New Discs - Now servo on!

[Howard J]

I recently bought a set of nearly new Armstrong wavey discs & pads off a mate of mine to fit on my 04 1200GS.

Since I have fitted them the brake servo is staying on unless I push the front brake lever away from the bars, I have tried adjusting the micro switch to no avail, Now I have noticed that the discs seem to look a bit thinner than the ones that were fitted so I am thinking that maybe the brakes need bleeding to make the brake lever return faster and all the way to turn the servo micro switch off? Does any one have any thoughts on this? could this be the problem?

This has been driving me mad for the past few days as I also fitted new levers, but I have now discounted this. HELP!!

 

[alex_rsa]

After having loads of fun trying to get the tailight to work properly, try this....


Remove the microswitch with it still connnected to the loom. Turn the ignition on with the microswitch depressed. You will notice a noise if you release the microswitch (I assume the servo). Depress the microswitch and pull in the lever, this should also trigger a servo but the noise is different. At this point you will probably get a warning light so turn the ignition on and off.

What you need to do now is refit the switch and adjust it and aim to get the 2 "servos" to trigger pretty much at the same time. It was a lot of trial and error (remember that depressed is "off" for the microswitch and this happens with the lever released). I got mine to release the microswitch slighlty before the lever as this triggers the taillight.

Good luck

Alex

 

[Howard J]

Thanks Alex, i think i may have sussed it now, it looks like when i put the new discs and pads in i pushed in the caliper pistons which forced brake fluid back into the servo overflow, leaving less fluid in the brake lines, which means the front brake lever plunger rod thing that goes into the master cylinder does not fully come out ( only by a few mm) when you release the lever, so it looks like the system needs bleeding, i have got it booked into Adventure Bike Wharehouse on Friday for Jono to bleed, hope this will sort it.

PS. There is no spring!

 

[cookie]

that doesn't sound right.

 

[Howard J]

that doesn't sound right.

Which bit?

 

[Deleted account 211025001]

Which bit?

I think Cookie means the lines needing bleeding

Yes, you will have pushed fluid back into the reservoir, but by squeezing the brake lever a few times you will push the pistons back out and the reservoir level will drop down to where it was before (or a wee bit lower if the discs are thinner). They only need bleeding if you got air into the system and I'm struggling to see how you have done that based on what you say

I'm not sure of the answer mind but think I'd be checking the micro switch was working properly and coming on when it should. Also, the obvious but common one of the brake lever being fouled by the hand guards...............

Andres

 

[cookie]

Which bit?

I think Cookie means the lines needing bleeding

Yes, you will have pushed fluid back into the reservoir, but by squeezing the brake lever a few times you will push the pistons back out and the reservoir level will drop down to where it was before (or a wee bit lower if the discs are thinner). They only need bleeding if you got air into the system and I'm struggling to see how you have done that based on what you say

I'm not sure of the answer mind but think I'd be checking the micro switch was working properly and coming on when it should. Also, the obvious but common one of the brake lever being fouled by the hand guards...............

Andres

that bit.

nothing you have said you've done would allow air into the system AFAICS

 

[Howard J]

http://www.ukgser.com/forums/showthread.php?t=253252&highlight=abs+fluid

See posts 5 & 6

 

[Deleted account 211025001]

http://www.ukgser.com/forums/showthread.php?t=253252&highlight=abs+fluid

See posts 5 & 6

Interesting............did you notice fluid pissing out of the reservoir then?

I'm STILL struggling to see how air could be introduced into the system though - it'll be interesting to see what ABW have to say when they get their mitts on it on Friday

andres

 

[Magwych]

This has been driving me mad for the past few days as I also fitted new levers, but I have now discounted this. HELP!!

How did you discount that removing and replacing the levers might have interfered with the operation of the microswitches that influence the operation of the servo? IMHO that would be my very first port of call ... If the master cylinder is not returning to its normal "resting" state then something could be preventing it?

Did you do any other works at the same time?

 

[Howard J]

How did you discount that removing and replacing the levers might have interfered with the operation of the microswitches that influence the operation of the servo? IMHO that would be my very first port of call ... If the master cylinder is not returning to its normal "resting" state then something could be preventing it?

Did you do any other works at the same time?

It was my first port of call, but to change the levers I used the main workings from the old levers, so there are no new parts that are used in conjunction with the master cylinder or the micro switch, I did at first think that I had lost a spring from where the plunger enters the master cylinder, but then after some research found out that there isn't one. The only other thing I can think of is that the master cylinder is worn, but it just seems a bit of a coincidence that it should prove faulty at the same time I have fitted levers and discs.

 

[trainman]

How did you discount that removing and replacing the levers might have interfered with the operation of the microswitches that influence the operation of the servo? IMHO that would be my very first port of call ... If the master cylinder is not returning to its normal "resting" state then something could be preventing it?

Did you do any other works at the same time?

agree, my moneys on levers, too much of a co incidence!!

 

[fizzer]

just some thing to think about ,my mate had a k1200r ,he put aftermarket levers on it and the brake light stayed on all the time.
just out of curiosity what happens if you take the brake lever off ,then turn the ignition on.

 

[Howard J]

Sorted, the front brake master cylinder was knackered, had to get a used one from motoworks for £90.

Big, big thanks to Jono at ABW in Manchester for sorting it all out today and coffee and sticky buns.

 

[Deleted account 211025001]

All's well that ends well

Andres