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ST1300 Archive of Wisdom / Re: Tony Worrall's "Pendle Parking Brake" ( ST1300 ) *
« Last post by KoTAOW on September 12, 2018, 07:13:29 PM »
Comments by Scott Chaisson, STOC #8642:  It's important to note that you should adjust the brake first, before you drill. The hole changes when the brake is adjusted.

At least, that's the way it seems to me on my bike. I've had it for ~2 years now. Works very well.
ST1100 Archive of Wisdom / Dash Shelf ( ST1100 ) *
« Last post by KoTAOW on September 12, 2018, 07:09:56 PM »
Contributed by Adrian, aka Totgas, STOC #XXXX.

Original article here:


Dash Shelf ( ST1100 )

Items Needed:
•   Aluminum sheet metal at least 2 mm/0.079" thick and checkerboard pattern
•   Angle grinder
•   Straight file
•   Different grades of sandpaper
•   Rubber mallet
•   Hacksaw blade
•   Drill and 2 mm/0.079" & 5 mm/0.197" drill bits
•   Scribe or sharp nail
•   Paint – metal primer and topcoat (recommend matt black)
•   Vice
•   1hr not including paint drying time
•   Small washers – Optional (6)

Note: the shape of this shelf (my own design) maximises available space without restricting your view of the warning lights.

I recently bought a new GPS (A TomTom Rider) to replace the ALDI one I had had for the last 4 years (A Go-Cruise) Great GPS – much maligned.

My original dash shelf was made of light weight metal and as a result the TomTom bounced around quite a lot.

First off I made a new mounting bracket instead of using the ram mount that came with the TomTom (as it was quite high) but the bounce continued. My plan was therefore to remove the bounce from the dash shelf by making a second shelf this time out of a much thicker material.

So off to Bunnings and I picked up a 2 mm/0.079" Checkerboard Aluminum sheet for $34.00.

My original 1mm shelf I was able to cutout with tin snips but this one was a little harder so I decided on the angle grinder. I removed my windscreen and then the existing shelf, bashed it with a rubber hammer (until it was quite dead and flat) and made up a template which needs to be mirrored.

After tracing the image on the back of the metal sheet I cut out the shape with the grinder. There was plenty of sheet left over for the next project.

However as you can see the grinder leave a fairly rough edge

So the first order of business is to remove all the rough edges with a file then sandpaper. Don’t be tempted to use a mechanical sanding device as it will damage the edges.

Finally sand the entire underside of the plate (which is actually the top of the shelf) as this creates a nice rough surface for the paint to bond to. Also using a hacksaw blade tidy up the cuts next to the front legs.

Place the shelve in the vice and using a rubber mallet bend the legs and side tabs accordingly. (I always bend these the wrong way initially so think about the direction they need to go in)

Now drill the holes with a 2 mm/0.079" drill and then the 5 mm/0.197". The holes need to be reasonably close to the edge as below.

With this done, you are ready for a test fit. I will guarantee that the holes will not align 100%.

However, the fact that we have made this out of aluminum means that the legs can be adjusted to fit perfectly. (Hint – always fit the side tabs first and never tighten any bolt up until all are in place)

Time for a final sand, clean and spray with a suitable primer for aluminum. (Hint – If you are going to mount accessories on the shelf [isn’t that what it’s for] and you know exactly where they are going, then drill the holes now).

I use dry gal as my primer for everything and it works fine.

After a suitable drying time (1hr for the Gal) spray the top coat or two.

Nearly there….. One final tip the front legs will be sitting on plastic that is not completely flat. If you are anal like me about your bike, you may want the stick three small washers together to place them between the leg and the plastic, this will prevent the plastic cracking over time – trust me)

Fit and farklise…


Thank You again for your contribution Adrian, aka Totgas, STOC #XXXX
ST1300 Archive of Wisdom / Tony Worrall's "Pendle Parking Brake" ( ST1300 ) *
« Last post by KoTAOW on August 26, 2018, 09:00:19 AM »
Contributed by Michael Moore, STOC #2636.


Tony Worrall's "Pendle Parking Brake" ( ST1300 )

I bought a ST 1300 a couple of months ago, and the one gadget I missed the most on the new 1300 was the Middleton Handbrake that I have had on my ST 1100 for the past 10 years. For those of you who didn't have an ST during the last century, the Middleton Handbrake was a clever little bit of stainless steel origami that allowed the rider to set the front brake to remain on. The park brake released automatically when the front brake lever was pulled in a bit further. It worked by putting a small tang in behind the brake lever when the brake lever was applied and the handbrake lever was moved up by the rider's thumb or forefinger. Clever and elegant engineering at its best.

With the handbrake fitted on your ST 1100, you could set it with a flick of the finger when at a stoplight, or parked at the side of the road looking at a map, or in any other situation where you didn't want the moto to roll in either direction, but wanted to be able to take your hand (and foot) off the brake lever. I used it constantly.

Middleton Handbrake for ST 1100

Mr. Middleton ran (runs?) a stainless steel shop in the UK. My guess is that he also rode a ST 1100, and developed this little goodie on his own. Unfortunately, it seems that he never bought a ST 1300 (and probably sold his ST 1100), because the original ST 1100 handbrake is now out of production, and there never was a handbrake made for the ST 1300.

...until Tony Worrall came along.

Tony (whom I am going to guess is a ST 1300 owner) has designed and is currently manufacturing and shipping handbrake kits for the ST 1300. I ordered a kit from him a couple of weeks ago, and when it arrived by post, I installed it on my ST 1300.

Here's what the contents of the kit look like:

Only the handbrake lever (top part) and the replacement brake lever bolt are actually installed on the ST 1300. The drill bit, flat piece of metal with the two holes, the nut and the washers are used during the installation process, and discarded afterwards.

The shape of the ST 1300 brake lever and the placement of the throttle cables is such that the original Middleton design cannot be used on the ST 1300. There's not enough space available - the throttle cables are in the way. Additionally, the inboard end of the brake lever is a little different on the 1300, and doesn't present an easy opportunity to slide a tang into place to keep the brake applied.

Tony has followed a different path designing his handbrake. Instead of attempting to keep the front brake applied by sticking something into the far inboard end of the brake lever, he's designed a device that fits into a small dimple (hole) drilled into the top of the front handbrake lever. The general principle is the same, though: To use it, you squeeze the front brake lever in the normal way, then press down on the top of a spring-loaded pin that is captive in the end of a bar mounted above the brake lever. This inserts the pin into the hole in the top of the lever. The pin is spring-loaded to pop up out of the hole in the brake lever, and the hole is larger than the pin. Thus, any further squeezing of the brake lever once the parking brake is applied will cause the pin to pop up and the handbrake to release. It works well.

Tony provides a complete set of illustrated instructions with the kit (the instructions are also available at his website, click here). I'm not going to attempt to duplicate his instructions here, but rather to provide a general overview of how the thing works, and what is involved in installing it.

First, you remove the front brake lever, and using the existing Honda bolt and the washers, nut, and drilling template that Tony provides, you mount the drilling template onto the top of the handbrake lever. The smaller hole on on the drilling template, on the right side of the picture below, shows where the hole will be drilled in the handbrake lever.

Drilling Template Mounted
The hole will be drilled more or less at the outboard end of the arrow embossed on the lever.

Hole Partially Drilled
I had to sneak a peek. The handgrip is 18 mm thick at this point, the hole will only be 5 mm deep

Hole Drilled, Everything Re-Installed

How it works (pin movement up and down into hole)

How it is Applied
To release it, just slightly squeeze the brake lever in the normal manner, no need to touch the parking brake, it will pop up.

What it looks like when Applied

I was a bit apprehensive about the idea of drilling a hole partway into the front brake lever. But, after thinking about it for a bit, I realized that the hole (a dimple, actually) is only 4 mm deep, and the handbrake lever is 18 mm thick at the point where the hole gets placed. Besides, Honda has already drilled a much larger hole completely through the handbrake lever casting - up where it pivots to apply the brake (where the bolt goes) - and I have heard no reports of the casting breaking where Honda put their hole.

I was also kind of apprehensive about my limited skill drilling holes in metal, but the task was made pretty simple by the template and drill bit that Tony provides. The only thing I had to pay attention to was making sure I did not drill any deeper than the 4 to 6 mm specified (final depth of my hole was 4.5 mm).

All told, it took about 30 minutes to carry out this installation, and 10 minutes of that time was fetching the drill and then putting the drill away.

The Pendle Parking Brake for the ST 1300 works as well as the original Middleton design for the ST 1100. I'm very happy with it, and recommend it without reservation to others. Be aware that it is only intended to be used when the rider is astride the motorcycle - in other words, if you want to park your bike on a hill using the side-stand, you put the engine in gear as you normally would. This handbrake would hold the moto parked on a hill, but if anyone bumps the front brake lever, the handbrake will instantly release, as it is designed to do.

The only addition I would make to the otherwise excellent instructions that Tony provides with the kit is to suggest that after installing everything, you apply a little bit of oil to the spring-loaded pin that goes up and down, to ensure that it extends and retracts easily and without any friction. It would be nice if the button on top of the spring-loaded pin was bigger... I'm going to keep my eyes open for something that I can put over it to provide a larger surface to push on. But, there is no problem operating the pin as it is now.

Tony sells these parking brakes on eBay for ₤30 ( about $50 US Dollars), shipping included. You'll have to go on eBay and search for "Pendle Parking Brake" to find it. His website, which contains information and installation instructions, is here. I believe that he sells a similar device for the ST 1100, but I am not familiar with that device.


Ooops, I forgot to mention that the amount of pressure that the handbrake exerts when applied can be adjusted using a small set-screw at the inboard end of the lever. Because this facility for adjustment is provided, fore and aft placement of the hole (when drilling it) is not critical. I chose to try and center the hole front to back in the brake lever, I think that position minimizes the risk of any cracks propagating in the casting as a result of the hole being drilled.

The adjustment set-screw allows for brake lever position to be changed using the chrome dial on the brake lever without any loss of efficiency of the parking brake.

Adjustment Set-Screw


Thank You again for your contribution Michael Moore, STOC #2636
ST1300 Archive of Wisdom / Common Torque Values and Wrench Sizes ( ST1300 ) *
« Last post by KoTAOW on August 10, 2018, 09:47:54 AM »
Contributed by Ray Antasek, STOC #XXX.


Common Torque Values and Wrench Sizes ( ST1300 )

Direct link to file:


Thank You again for your contribution Ray Antasek, STOC #XXX
ST1100 Archive of Wisdom / Wheel Bearing R&R Tip: Distance Collar Mod ( ST1100 ) *
« Last post by KoTAOW on July 08, 2018, 07:56:06 PM »
Original idea by Paul Kolbo, STOC #273, text and pictures by John OoSTerhuis, STOC #1058


Wheel Bearing R&R Tip: Distance Collar Mod ( ST1100 )

If you've ever had difficulty removing an ST's wheel bearings, it's usually because the Distance Collar is so tightly wedged that you can't move it enough to get at the bearing properly.  BTDT!... 

While you've got the Distance Collar out, grind a couple of notches on the ID of one end so that whatever driver/drift/rod you are using will have better purchase on the backside of the inner race of the bearing you're pounding out.  I don't have a Distance Collar handy so I used a piece of PVC pipe to simulate the real thing, and added some black marker for clarity:

You only have to do this to one end of the Distance Collar.  I recommend placing the notched end to the left side of ST1100 wheels, for consistency front and rear, and because the rear wheel's right side bearing is a double-row type.  The double-row bearing will be easier to remove after the left side, single-row bearing is out.


Thank You again for your contribution Paul Kolbo, STOC #273 and John OoSTerhuis, STOC #1058
Submitted by Alan Wilson, STOC #XXXX
Location:8 Grahamsdyke Road, Bo’Ness. West Lothian. EH51 9EG
Contact email:

Original article is located here:


How to replace the Water Pump Bearing and Seal ( ST1100 )


Parts available on ebay at this link:

Price: GBP 49.99
Approximately US $66.15 (June 2018 )



You will need a small press for this, don’t try and use a vice or large mallet.

The hotter you get the pump casting the easier the bearing will press out. So remove the rubber band seal and idler bearing.

Decide now where and how you will support the casting in the press. It must be very close to the bearing.

Put the pump assembly into your kitchen oven and cook at 200 C for 10 mins, do that when the wife is out because it will smoke a bit.

Use gloves to remove.

Make sure the casting is well supported close to the bearing when you press, if you see the casting flex, stop because you haven’t got it supported well enough.

Read though these instructions a few times to make sure you understand the steps, they were written with mechanics in mind not for someone who thinks you press with an ironing board.

1. Press the bearing out using a 4 or 5 mm hex ½”  or 3/8”  socket drive.

Press though the hole in the fan end just as far as the length of the hex will allow you.

Any other attempt at removing the fan first will damage it

If you didn’t use the oven pouring some boiling water over the casting will loosen the bearing.

2. Once you have pressed the length of the hex key, raise the press and lift off the fan.

3. Finish off the pressing using a 1/4 "drive long 8mm socket, the bearing will fall out below.

4. Press or tap out the seal cup using a socket.

5. Press off the pulley from the bearing.

6. There are two bleed vent holes between the seal and the bearing, and the outside edge of the pump, make sure they are clear.

They tend to corrode closed due to the seal leaking and are a pain to clear but has to be done.

One is shown with a screwdriver, the other is show at about the 7 O’clock position

7. Reassemble, Press in the new bearing from the pulley side until the edge is flush with the casting. Use a 22mm socket.

8. Press in the new seal cup using a 27mm socket.

9. Press on the pulley wheel until the shaft protrudes by 1mm out of the pulley.

10. Put the fan onto a flat surface and check the blades are straight, they will probably be bent a very little so straighten them out.

11. Remove the old seal and clean out the hole. Fit the new rubber seal into the fan using a little silicon sealant, this maybe a tight fit, looser is best so don't force, rub the rubber seal around the edge with some sand paper to achieve a "fall in fit" if required.

Fit the white ceramic washer, the side with the black marking goes against the rubber, don’t mix it up or the seal may not be water tight.

12. Press the fan fully onto the shaft.

13. Check the fan clearance, it should be about 1mm, closer is fine but higher risks the fan hitting the engine block. Make sure it turns freely.

It is lubed by the coolant so it will be a little stiff, don’t get or put oil on the ceramic surface, it can be contaminated and not seal.


Thank You again for your contribution Alan Wilson, STOC #XXXX
ST1100 Archive of Wisdom / Rebuilding the Water Pump ( ST1100 ) *
« Last post by KoTAOW on June 27, 2018, 10:26:09 PM »
Submitted by Terry Smith, STOC #8901


Rebuilding the Water Pump ( ST1100 )

Complete water pumps are unavailable for the early ST’s new, but I was able to find a vendor on
eBay, who sells a rebuild kit for GBP68.99, shipped to anywhere. 

Ebay store is located here:

Web page here:

Some of the photos below are from the vendor’s website. The same kit can also be used on later model ST1100’s. The vendor (Alan) was helpful via text using the number on his website.


The water pump seal and/or the o-ring on the pump housing began leaking on my 28-year old bike
at around 125,000km.

The pulley and impellor get re-used, so need to be pressed out of the original housing.

The parts supplied consisted of a new shaft and bearings, ceramic seal, stationary seal and rubber
seal for the impellor.

To access the pump, you will need to remove the bodywork, drain and remove the radiator, then
remove the timing belt covers and the timing belt, plus the tensioner and idler pulleys. You will also
need to remove one of the cam pulleys and the cover that bolts to the cylinder head (I did the left
side), without that you have no way of getting the pump housing out of the bike; you will probably
need a new gasket for this one (14525-MY3-000). I also ordered a new pump o-ring (19226-MT3-
) and the idler pulley (14560-MT3-003) as that had a loose bearing.

Once the 7 bolts are removed the pump housing can be removed from the front of the engine, I
used a pry bar to get it moving. I disconnected the oil-cooler water hose at the cooler, plus the hose
guide that shares the case bolts, as it was impractical to get it off the water pump housing in place.

The instruction supplied by the vendor show the use of a hydraulic press to separate and reinstate
the parts, I don’t have access to a press so relied on using a large hammer.
Firstly, support the pump housing well, close to the pulley, with the impellor facing up, then drive
the shaft/bearings out by pressing on the end of the shaft visible through the hole in the impellor. I
used a 5mm allen key bit mounted on the end of a short extension bar of my ½” socket set. The
socket on the end of the extension bar took a bit of a beating but is still usable.

This required some big hits to shift, and the vendor recommends heating the housing by pouring
boiling water onto it which will make the alloy parts expand (you could also heat it in an oven,
apparently that will stink up your kitchen, you have been warned).

After the first bit of movement the impellor will make contact with the housing and then slide up off
the shaft, and can be removed. You can switch to an 8mm socket bit and continue to drive the
shaft/bearings fully out of the housing.

You now need to separate the pulley from the shaft; support the pulley well, then drive the shaft out
of the pulley fully using the 8mm diameter bit.

You can now drive the old seal out of the housing using a 16mm socket. I cleaned up the pulley
bearing housing with fine sandpaper to make reinstallation easier and added a little grease. I took
time to clean the pump housing fully as well. This includes the two weep holes at right angles to the
shaft axis.

I drove the new bearing and axle into the pump housing using a 22mm socket, until the surface of
bearing was flush with the edge of the housing. To make this easier I heated the pump housing with
a hot air gun, and chilled the bearing/shaft in my freezer first.

Flip the assembly over, and gently press the pump stationary seal into the housing using a 22mm

Now the pulley can be re-fitted, driven onto the shaft which I supported well from below so all the
load is transferred to the support, not through the bearings. The pulley should be driven until the
shaft projects by 1mm.


The impellor should be checked/trued for flatness in case the removal process bent it; mine was

The rubber seal is now fitted into the impellor hub with a small amount of silicon sealer, then the
ceramic seal is fitted. The seal has a glossy side, and a machined matte side; the matte side should
face the stationary seal in the pump housing. Don’t apply any lubricant other than coolant to this

The impellor is now placed on the shaft and driven home, again the shaft needs to be supported
from below so no force is imparted to the bearing. There was a final clearance of about 1mm
between the pump housing and the impellor.


And…you’re done.
You will find that the seal is a little stiff (it is lubricated by coolant) so the impellor won’t turn that
freely. Don’t panic.


Thank You again for your contribution Terry Smith, STOC #8901
ST1100 Archive of Wisdom / Electric Fuel Pump Option ( ST1100 ) *
« Last post by KoTAOW on March 26, 2018, 06:41:49 PM »
Contributed by Dale Isley, STOC #5341.


Electric Fuel Pump Option ( ST1100 )

I thought I might post my solution to replacing a dead fuel pump on an ST1100. A lot of people have used Carter or Honda Automotive pumps and attached them to the stock fuel pump assembly. I decided to go electric and mounted it to replace the Auto Fuel Valve that many have already removed from their systems.

In this application you simply leave the dead pump and everything in your fuel tank alone. The Facet pump will use the old dead tank set up as a pick up tube.

NAPA has a part number 610-3021 which is the Facet Posi-Flow pump and even came branded that way. Rated at 1psi-2psi at 7gph (this is the lowest rating... some sites have it rated as much as 1.5psi-2.5psi at 25gph) I thought it would be a better fit that the 40178, 40177, etc, etc. Since it is a Posi-Flow it is rounder than the Cube and should fit easier as well. It is about $70 - $80 at the time of my purchase through NAPA. It can be had for a bit less online, but I wasn't willing to wait for the little savings once shipping was added to their lower price.

The Facet Posi-Flow page here: shows it as the 60304, rated on the Facet site as 1psi-2psi 15gph with a 50" wet lift.

I fabricated this bracket and painted it black. This will locate the pump on the right side of the air filter housing using the bracket from the Auto Fuel Valve.

You will need to add a 90 degree fitting to the outflow side. The stock outflow fuel line has a 90 degree bend molded into it. You will be removing the molded bend from the fuel line and once cut you will attach it to the fitting. There is a 45 degree fitting on the inflow toward the tank, where I inserted an inline fuel filter. The Fuel Filter is NAPA Part number 610-1085 and it is a Balkamp part number FEP735.

This is the bracket with pump and fittings attached to the Auto Fuel Valve bracket ready to bolt to the air filter housing.

A few pictures showing the position of everything in place.

Pump power was pulled from the spade connector going to the stock pump.

Here is a picture of the new pump, wiring, and you'll notice I wrapped the inline fuel filter in some closed cell foam with a zip tie. This is to protect the plastic once the air filter cover is installed.

Tupperware going back on... this picture was taken before I wrapped the electical with protective plastic loom, which you can see on the previous picture.

While it is all apart, remove the rubber insert around your fuel cap, drill a hole through the bottom of the idle adjuster hold down, and thread a zip to hold that sucker. Makes turning the knob to adjust your idle SO EASY!

I've been running this configuration for about a year, over 8k miles, and have not had any issues.

As I said, just an option. I can carry an extra fuel pump and filter in my under seat storage with my tools and be able to change it out on the road if failure occurs.


Thank You again for your contribution ]Dale Isley, STOC #5341
ST1300 Archive of Wisdom / LED Headlight Conversion ( ST1300 ) *
« Last post by KoTAOW on January 09, 2018, 02:03:44 PM »
Submitted by aka JayBear, STOC #XXXX
Original posting link:


LED Headlight Conversion ( ST1300 )

How many ST riders does it take to change a light bulb

Hello fellow ST riders!

If you're trying to figure out how to install your new LED headlights then you have come to the right place. I recently changed out the lighting on the front of my ST1300 to all LEDs and realized information on the process was scattered all over so I decided to document my entire process by taking photos along the way. My hope is that this guide will help you to visualize the process and help you understand the mechanisms involved so that you can spend less time fumbling around and looking all over the threads for info.

Disclaimer: I am not a mechanic, electrical engineer, or a rocket scientist (go figure)! I am just an average DIY-er so use this information accordingly. Enough chit-chat, let's get to it!


It is important to note that the tabs on the OEM bulb and the notches on the OEM housing do not have the same angle as an aftermarket H4 bulb (see photo below for comparison).

Notice the bottom two tabs on the OEM bulb are more spread out. Because of this you will need to modify the new bulb.
Common solutions are
  • Cut the tabs off
  • Bend the tabs back, or
  • Use shims

WHAT ARE SHIMS? They are metal rings cut to match the OEM tab angle. You just slip them on over the bulb so that you can lock them in place. Although not required for this project I want to share the info here.

Next item is how to access the bulbs. I used option #3 but other common solutions are (see images)
  • Reach in from from the front of the bike and below the headlight housing
  • Reach in from above behind the handlebars
  • Remove the dash/instrument panel
  • Remove the front windscreen and surrounding plastics
  • Remove side fairings


Locate the headlight. You will see a big round rubber boot with an electrical connector in the middle. You need to remove this connector. To do this you need to press down on the tabs located on either side of the connector (see image). You may need to dig your fingers into the boot a little bit to reach these tabs. You are disconnecting the harness from the bulb so you should only have to pull straight out but some wiggling may be required.

Once you have the connector from the wiring harness out, remove the rubber boot. Just grab from the edges and pull/peel back.

When the boot is off it will reveal the wire clip and the bulb. Now unlatch the wire clip, or bail clip, by pushing in with your thumb and turning slightly. The clip will unhook and swing open to free the bulb from the housing.

Then remove the bulb. Just pull straight out. Be careful not to let your fingers touch the glass if you plan on keeping the bulbs. If you do accidentally touch the glass then use a small amount of rubbing alcohol to clean it.

Now before you insert the new LED bulb you will need to modify it as mentioned earlier. Choose your weapon. I used a Dremel with a metal cutting wheel bit to cut and file off the lower two tabs.

You need to know that the mounting plate (blue arrow, see image) that has the three tabs is removable. Just hold the plate with one hand the the fan with your other hand and twist. That will release the plate.

Now take the mounting plate (blue arrow, see image) and insert into the headlight housing by itself. Do not attach it to the bulb or else it will not fit! It will all make sense later. You must align the top tab with the notch in the housing (see image).

When you have the mounting plate inserted re-insert the wire clip to hold it down. This might take a while

Now that the clip is back in put the rubber boot back on. Still no bulb should be inserted! I have seen posts where people leave the rubber boot off or even cut it up to make the hole wider but this is not required.

Okay, now you can insert the LED bulb in through the rubber boot. Remember those notches on the bulb from when you removed the mounting plate? Well you need to align them so that you can insert the bulb and then twist to lock it back in place. It will help to look through the front of the housing when you insert the bulb. Look for the notch to help you with the alignment (blue arrow, see image).

After you have the bulb locked in you're almost done. Just plug the electrical connector to the new bulb and tuck away and zip-tie the wires and the LED driver (ballast/box thing). I tied them off to the side so that it would not interfere when turning the handle bars.


Next we will replace the position lights, or park lights, or marker lights. The little guys in the top corner (see images).

Locate the bulb socket. You will find a small rubber boot at the end of the wiring harness (see image). Pull this rubber socket straight out, but use caution! There is nothing really "locking" the bulb on so as you pull, the bulb may dislodge from the rubber socket and fall into the housing.

Once you have the socket removed simply pull the old bulb out, and plug in the new LED.

ALL DONE!!!! Now get out and ride! Stay safe!


Thank You again for your contribution aka JayBear, STOC #XXXX
* * * Article pending permission by Author * * *

Submitted by John Heath, STOC #XXXX
Original article can be found here:


Brakes - Operation of the Master Cylinder ( ST1100\ST1300 )

Some basic information here about the operation of the brake master cylinder.

This document was last edited on 17 July 2017 to remove references to 'relief port' and use the more correct 'compensating port'.

1 - 'Relaxed' Brake Master Cylinder (ie Brakes are not Applied)

The image shows the front master cylinder and the reservoir immediately above it - just like the ones used on the clutch and brake lever on the ST1300. The piston and push rod are shown in grey.

The primary seal (blue) is the one that applies considerable pressure to the braking system.

The secondary seal (black) maintains a body of fluid behind the primary seal which is gravity fed from the reservoir above. It also isolates the system from the outside world. This seal is never normally put under any great (ie braking force) pressure. The ST1300s secondary master cylinder being an exception to this arrangement.

Note the larger inlet port between the reservoir and the piston/cylinder. This maintains a volume of fluid between the two seals, fed constantly from the reservoir. The inlet port is never closed off by the position of the piston and seals.

The tiny compensating port is immediately in front (just to the left) of the primary seal. This allows fluid in the braking system to return into the reservoir and relieves any build up of pressure when the braking system is in this 'relaxed' state.

The spring is responsible for returning the piston to the right on this diagram. The push rod at the right hand end is operated by the brake lever.

The hose to the brake calliper is shown descending beyond the bottom of the picture on the left of the master cylinder.


2 - Master Cylinder when Brake is Applied

In Diagram 2, the piston has been pushed to the left. Fluid under pressure (pink) is forced down the brake line to the pistons in the brake caliper. Note that the primary seal (blue) has moved past the compensating port, preventing any fluid from returning to the reservoir. The fluid under pressure is responsible for pushing out the pistons in the brake calliper which push the brake pads onto the disc rotors. Once the brake pads are in contact with the disc rotors it takes only a small movement in the master cylinder (brake lever) to exert a force sufficient to bring the bike to a halt.


3 - Releasing the Brake Lever

When the brake lever is released, the piston and plunger are returned to the initial 'relaxed' position primarily as a result of the spring pressure in the master cylinder, but aided by the flexible hoses and the calliper piston seals returning to their normal state.

Each time the brakes are applied, the pads wear down a tiny fraction, and the calliper pistons are pushed out further than they were before the brakes were applied. When the brakes are released, the spring returns the master cylinder piston to its relaxed state and a negative pressure (vacuum) is created in the brake lines. Fluid is able to flow past the lips of the primary seal to allow for the fact that the pads have worn down a little.

The diagram shows the piston towards the end of its travel back to its 'relaxed' state, and the red arrow indicates the flow of extra fluid from the yellow reservoir fluid and into the brake lines (green fluid).


4 - Dealing with Pressure Build-up

When the brake is not being applied, and the system is in a relaxed state, it is important that fluid is able to 'flow' to and from the reservoir as required. This is can happen when:-

* A slight warps in the disc rotors or general chattering of the brakes over bumpy surfaces pushes the pistons in slightly.
* An increases in temperature causes the fluid to expand.
* The bike cools down in the garage overnight and the fluid contracts. The relief port allows fluid to flow into the brake lines rather than suck the calliper pistons back.
* The brake pads are replaced and the calliper pistons are pushed in. The displaced fluid returns to the reservoir through the tiny relief port. No damage can result in pushing in the calliper pistons in this way if the system has been flushed with new fluid and the exposed calliper pistons are clean. Otherwise it is better to expel the old fluid from the calliper bores via the bleed valve.

The picture shows the pressure in the brake line being allowed to pass through the tiny compensating port into the reservoir, once the brake lever has been released. To prevent the 'fountain' shown in the diagram, a small chromed disc clips slightly above the port at the bottom of the reservoir.


5 - Blocked Pressure Relief Port

If the piston is prevented from returning to its proper 'relaxed' state, then the Primary Seal will not expose the tiny compensating port. This could be caused by corrosion behind the piston, as shown. This part of the piston is open to the elements unless treated with silicone grease and covered with a rubber boot.

Alternatively, the compensating port itself could be blocked. Fluid that isn't replaced every year can turn into a thick gel which accumulates in the bottom of the reservoir. Or perhaps debris has fallen into the reservoir during a service.

Whatever, if the compensating port is not clear, or the piston fails to return properly to expose the compensating port, pressure builds up (red) and the brakes lock on solid. I have seen one situation recently where a master cylinder service kit was supplied incorrectly. The push rod was slightly too long and front brakes locked on solid at the first application and would not release.


The illustrations refer to the ST1300 front master cylinder, but the principles also apply to the secondary master cylinder and the rear master cylinder, even though their relief port is connected to the fluid inlet line rather than to the reservoir itself.


Final note. Throughout this document, I have made much more of the role of the compensating port in relieving pressure than its other functions.

In fact, the port will allow fluid to flow in either direction to add or remove fluid from the lines to compensate for the fact that the existing fluid will expand or contract as the temperature fluctuates. To do this, the master cylinder piston has to be returned to its relaxed position so that the port is not blocked by the seal. The spring in the master cylinder ensures that this happens.


Thank You again for your contribution John Heath, STOC #XXXX
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