[working class hero]

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THIS FORUM IS TRULY THE FONT OF ALL KNOWLEDGE REGARDING GOLDWINGS SO I HOPE THAT SOMEONE CAN SHED SOME LIGHT ON MY PARTICULAR PROBLEM I HAVE AN 86 1200 ASP AND I HAVE LITTLE OR NO RESISTANCE FROM MY REAR BRAKE PEDAL UNLESS I PUMP IT FIVE OR SIX TIMES AND THEN THE REAR CALIPER WILL LOCK SOLID AND WILL ONLY RELEASE IF I LEAVE IT FOR A WHILE OR RELEASE THE PRESSURE AT THE BLEED NIPPLE BOTH FRONT CALIPERS SEEM TO BE OPERATING FINE I HAVE CHANGED THE PADS, CLEANED THE PISTONS, REPLACED THE SEALS, GREASED THE BUSHINGS AND TRIED FOR HOURS TO BLEED THE SYSTEM BUT ALL TO NO AVAIL I DID TRY RIDING THE BIKE USING JUST THE FRONT BRAKE BUT AFTER A MILE OR SO THE REAR AND FRONT RIGHT CALIPERS GRADUALLY LOCKED SOLID AND COULD ONLY BE RELEASED BY ALLOWING TO COOL OR RELEASING PRESSURE FROM THE BLEED NIPPLE WHICH SQUIRTED OUT LIKE A WATER PISTOL AND WAS VERY HOT :shock: I DID TRY TO INVESTIGATE THE MASTER CYLINDER BUT TO MY HORROR FOUND BOTH NUTS ON THE BRAKE PIPES ROUNDED OFF , SO I NEED TO KNOW DO I PURSUE THE TRAPPED AIR ROUTE? OR THE MASTER CYLINDER? AS THE LATTER IS NOW A JOB I WOULD LIKE TO AVOID.
I SHALL SIT BACK--------------- RELAX-------------- AND AWAIT YOUR PEARLS OF WISDOM!
TAS.

 

[globetrotter]

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Tas, please use lower case - upper case is like shouting at people.

You did not say what bike it was (reread and you did). Later bikes have linked braking systems. My first guess is the master cylinder unless when you refurbished the rear calipers you put the seals in wrong although that should not be the case if when you open up the bleed nipple it releases the pistons. Have you checked that the piston in the master cylinder is returning. Pump the rear a few times and see if there is any play between the pushrod and the plunger - if so the master cylinder piston need cleaning and new seals etc.

 

[tricky]

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jees that uppercase is hard to read.

the 84-87 models also have linked braking. the front right and rear are applied with the foot peddle.


Check that the calipers are floating freely on the slide pins, that would also cause the brake caliper to seize and get so hot you cant touch it. Oops I said it was hard to read, It seems you did a rebuild

If that doesnt solve the problem I would suggest taking the master cylinder apart, (right side under the side cover) it could be there is some junk in there preventing the caliper from releasing. You may have picked up some kangaroo droppings in your travels


(after trying the first suggestion)

 

[exavid]

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:waving::waving:Welcome to the Best Goldwing Site on the Internet! Working...:waving::waving:

I'd say you need to work over the rear master cylinder. The need to pump several times is either air still in the system or a master that isn't holding pressure. The locking up of the calipersis most likelycrud in the master. If a single caliper locked up it could be a bad brake line coming apart internally but since both of your linked brakes locked up it seems to me it would have to be caused by the master not releasing the pressure. When you release the foot brake pedal, the piston in the master moves back to release the pressure and unports a passage to allow the excess fluid to return to the master reservoir. If that port is plugged the pressure will build up and lock.

It's also possible that air in the system is making things worse, compressed air in the lines, caliper or master can do odd things too. When you bleed the linked system it's best if you bleed the brake farthest from the master which is the front brake first. Once you have that running without bubbles, do the rear and then repeat a couple times. You may have to crack the brake lines at the caliper and master to get rid of all the air. When I bleed hydraulic brakes, I always use a tube attached to the bleeder that goes into the bottom of a jar of can with an inch of brake fluid in the bottom covering the end of the tube. That way no air can accidently be sucked back into the system if you accidently let go of the pedal with the bleeder open.

 

[ARKYMAN2003]

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i agree with exavid exactly... had the same sort of lockup problem with

a GL500 silverwing earlier in the summer.. the passage in the handle bar

master cylinder had become clogged... I blew it clean and wolved the

problem. If that passage stays clogged, you will never get the pressure

release when the footlever/handlebar control returns to rest. I haven't

be "in" to my (rear) GW master cylinder yet, but I will be inspecting mine

soon, I fear, because of the way it's acting the last few days...good luck!

arkyman

 

[DJ]

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The problem will be in the rear master cylinder as this controls one of the front calipers and the back one. I'd be checking the vent in the MC for sure, as this allows the fluid to return when you release the pedal.
Brake hoses breaking down internally can also cause this problem, but its doubtful if front and back hoses would go like this at the same time.

 

[working class hero]

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Apologies for the upper case I live and learn, so the general consensus appears to point toward the master cylinder I just wish that there was a definitive test I could do to rule out air in the brake line anyway thanks for your replies and I shall let you know what I find.
TAS

 

[rcmatt007]

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probably the best test to see if it is air is to bleed the system and see if it gets better... as several have mentioned the linked brake can be a bugger (is it okay to use that word in England?) I haven't, but other use the vacumn system to bleed which is better at geeting air out. also, I learned the hard way, the stuck cliper pin can also cause troubles with brakes.

 

[07Silver]

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TAS, Goldwings are a pain to bleed the linked brakes. Why not inject the fluid from the nipple end? This usually works (assuming the master cylinder is good) and there are loads of posts on the forum about how to do this.

 

[working class hero]

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Well I finally managed to remove my master cylinder and opened it up to replace the seals problem is when I opened it everything inside jumped out onto the floor I have got myself a repair kit problem is i dont know what order it all goes back in my main problem is whether the small rubber cup goes in first to hold the spring or does the spring go in first and then the rubber cup to act as a buffer between the spring and the piston? anybody out there who has done one recently can shed some light Thanks. Tas

 

[exavid]

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working class hero wrote:

Well I finally managed to remove my master cylinder and opened it up to replace the seals problem is when I opened it everything inside jumped out onto the floor I have got myself a repair kit problem is i dont know what order it all goes back in my main problem is whether the small rubber cup goes in first to hold the spring or does the spring go in first and then the rubber cup to act as a buffer between the spring and the piston? anybody out there who has done one recently can shed some light Thanks. Tas

Tas, here's a print from the parts list, I hope you can make it out well enough to use. If not let me know and I'll try again. Unfortunately my parts book doesn't identify allthe parts it just calls it a piston assembly.

 

[working class hero]

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Thanks for that Exavid it would appear that its spring , rubber cap then piston unless any body knows different . TAS

 

[working class hero]

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I rebuilt the rear master cylinder as the seals did look a tad worn and also replaced the rear caliper as one of the bores looked a bit dodgy and this has seemed to solve my problem but bleeding those linked brakes man what a nightmare , cracking joints both ends ,syringing forward and backwards leaving the pedal depressed overnight but I got there in the end thanks for all the advice:cheeky1: . Tas