Steve Saunders Goldwing Forums banner

Status
Not open for further replies.
1 - 20 of 33 Posts

·
Premium Member
Joined
·
12 Posts
Discussion Starter #1
imported post

Hello everybody!! Im fairly new to this forum, and loving it!!! such a friendlyplace!!

I have this problem: the rear brakes of my 91 interstate all of a sudden start to stick to the disks.. the only way to free it is by loosing eitherthe rear or front bleeder,after getting some fluid out, I can roll it again... My gues was that the rear master cyl needed to be rebuilt, so I did it, following the clymer manual instructions(and this forum, of course), I took special attention on getting clear that little mini-hole, so im sure is not blocked, after putting everything back again, bleeding the system, and crossing my fingers, the bike roll fine for about 10 miles, but after a while it locked again....!!!
So I re-did the same thing: cleaned every component, make sure again that little pinhole wasn't blocked, reinstall the system, bleed it again, crossed my fingers (this time I let it running on the center stand), let it run for about 10 minutes, making shifts, applying the brakes....and it started to lock agailn...until totally locked both tires....so i had to release the bleeder again...Soooo, the master cyl is again in my hand...and I notice something:when I press the spring and the seal in the bore of the cylinder, sometimes it won't come back to the top of the bore!! is that normal?..my common sense tellme that I might need to use an extra fine sand paper inside the cylinder...I can't see any rust or obviuos imperfection...Of course Im trying to avoid buying the whole master cyl...any advice will be greatly appreciated...Thanks
 

·
Official "Cheeky Plonker"
Joined
·
1,204 Posts
imported post

You Sir, have a stopped up return hole in your master cylinder, I personally have no experience with your master cylinder but I can assure you that there will be someone along soon that does.
 

·
Administrator
Joined
·
26,177 Posts
imported post

You are right about the piston not returning in the MC, it could cause that. I would think the pressure build up would push it back but maybe not. If the inner cup is not returning past the return hole it is blocking the fluid. The bore of the cylinder needs to be shiny smooth.
 

·
Premium Member
Joined
·
1,235 Posts
imported post

Do you have a floating type caliper on the back? If so, remove the caliper and see if the slide pins need to be cleaned up. Do you have the split system like the 1200 where the rear and one front brake apply at same time? If so, do both stick or only the rear? If both do, the problem might be in the master feeding both brakes. You might need to rebuild the master cylinder. Hard to say.
 

·
Premium Member
Joined
·
12 Posts
Discussion Starter #5
imported post

Thanks for your quick reply gentlemen!! This bike has a linked brake system (rear cylinder controls the rear and left front Brake). In order for me to make it roll again, I Have to release presure from either the front or rear bleeder.... What do u mean I have to rebuld the master cyl? I thought I did by replacing the cup, spring, and other components for the cylinder....Basically my question is if is normal for the plastic cup at the end of the spring to be stuck at about 3/4 of the lenght of the cylinder...and I insist, the return hole is clean!...Your help and/or comments are very appreciated....thank you very much!!
 

·
Premium Member
Joined
·
650 Posts
imported post

Recently put new EBC HH pads on rear wheel['95 SE]. Foundlower rear caliper pin FROZEN solid from seriousrust/corrosion. Due tothis, calipercould notfloat; oneHH padwore downto metal backer, whileotheris still ingood shape[enough to keepas a spare]. Was a bugger to removepin, even w/PB Blaster! Got new pin/boots from Venco; used anti-sieze when reassembling. But,need new rear caliper inspring!
Afterbore was cleaned, new pinfit way too loose [excessive wear/corrosion had occured to the aluminum]. Thisnow puts stress on caliper when brake is applied, asit cannot float left/right smoothly and isbinding. My 2 cents.......Tom
 

·
Premium Member
Joined
·
6,422 Posts
imported post

No, The plunger should return all the way.
How full is the resivor If you fill it over the max fill line it can cause a problem like you are describeing. but I would check The bore agian . any time when rebuilding the Mastercylinder light hone with fine stone and be shure to move in and out while honeing.That bore must be clean and no pitting. also calipers may have moisture and dirt in them.as well did you flush system before rebuild.?If not you may be picking up trash back into the tiny return Hole
also make shure you are useing clean new fluid of the
recomened # on cap. and make shure you have proper amount of free play in pedal.
 

·
Registered
Joined
·
2,795 Posts
imported post

It might also be caused by a Collapsed Brake Line... eg If a brake caliper is removed and left hanging, it can put a non-visable kink in the brake line, which prohibits movement of fluid... which does not allow the brakes to release.
 

·
Administrator
Joined
·
26,177 Posts
imported post

ALEX BERECZKY wrote:
It might also be caused by a Collapsed Brake Line... eg If a brake caliper is removed and left hanging, it can put a non-visable kink in the brake line, which prohibits movement of fluid... which does not allow the brakes to release.
Except his has both front and rear not releasing and opening either bleeder releases them both and the lines are separate.
 

·
Premium Member
Joined
·
1,424 Posts
imported post

i insisted the hole was clean on mine too untill mine kept locking up repeatedly and stranding me...i drilled that little bitch out and it worked perfectly to this day....you might need just use a peice of wire and/or something might be floating back into the hole
 

·
Premium Member
Joined
·
12 Posts
Discussion Starter #11
imported post

Hello to everybody

I haven't had time to work in the GW until today; i just used a metal sponge grade 000 instead of any sandpaper to make the inside of the cylinder real smooth; it changed a lot, it looks really shine in the inside!! Probably you guys wont aprove what I did to make sure the little pinhole is clean: I run water under presure thru the cylinder and I could clearly see two streams of water out; after that I double cleaned it with alcohol and let if soaking with DOT4 for some time...so im positive the pinhole is clean...I put it back and made a small test ride for about 5 minutes without any failure, but, being in texas, it start to rain and had to come backhome...will post of the results tomorrow. You guy are the best, thanks again to everybody...PS: I rode it without the exhaust chamber and mufflers, and did like it the sound!!! How bad could it be to skip the exhaust chamber at all?
 

·
Premium Member
Joined
·
28,832 Posts
imported post

Just want to say something here on this thread. We change our OIL Regularly we change our Plugs and filters. But on a bike it's also important to change our Brake fluid every once in a while. It gets dirty like everything else and that dirt will lead to this and other types of Failures. So look at the color every once in a while if its turned dirty. Just bleed the brakes and get the old fluid out. Brake fluid isn't that expensive that it's not worth doing so just remember.
 

·
Premium Member
Joined
·
815 Posts
imported post

Agree with purple pirate.

The PO of my bike obviously had never done it and it was like a dark sludge.

Drained and refilled with nice clear fluid.

Cost is minimal and like to have working brakes !!






.
 

·
Premium Member
Joined
·
206 Posts
imported post

Better check the caliper before you look any further. I was advised and found to be true that the pistons can gum up pretty quickly. The shop that gave me that advice said they'd seen it in as little as 40,000 miles.

Because of uneven pad wear, I pulled mine apart (at 140,000 miles) and it was surprising the pistons would move at all. I had to scrape out every groove, clean up the pistons, replace all seals and dress the cylinder walls to restore proper function. Your caliper could be stuck.

Jack
 

·
Premium Member
Joined
·
12 Posts
Discussion Starter #15
imported post

Well, raining again here in this side of TX....still took bike for a test ride....about 10 miles and bakes locked again...I have to carry my 10mm wrench to loose pressure fom front disk brake in the middle of the road...lol...Both tires get locked when this happend, but releasing pressure from any of them will make the bike to roll again...I guess I have to check every single advice you guys had gave to me...Is personal now...LOL...I will check for 1) Colapsed lines....2)sticky calipers (gum)....3)Will change brake oil again(BTW, Im using a valvoline DOT 3 and 4)... and... what other suggestions??...Thank to all of you guys, you are great....will keep you posted.
 

·
Premium Member
Joined
·
12 Posts
Discussion Starter #17
imported post

Hello everybody!! Another week I miss riding my gw because of brakes!!!I checked everything you guys told me, did not work. Got so frustated that i ended up buyin a used (i know) rear caliper and master cyl fro a WORKING gw, cleaned both parts, installed, and still not working....I hired somebody to help me with the problem, he diagnosticated maybe a line from the cyl to the front brake is colapsed because of the heads heat, it made sense to me, so insted of tracking the line i decided to cancel temporarely the front line directly from the master cylinder, so at this time the master cyl is working only in the rear caliper...well it happened again...bike is unable to move at all! I interchange one and another rear caliper and master cylinder, same problem...the guy I hire to helpme, toldme to buy a brand new rear caliper (around $500 from the dealer), which Im trying to avoid from the begining...still if I buy it, im afraid is other part the problem...he tested the master cyl and assured to me both master cylinders were working...I see as to much coincidence that both rear caliper did not work, he toldme that maybe I damaged the piston seals when put them back...as mather of fact, it was really hard to separate the pads from one of the caipers, so my next step is goin go replace the seals (pistons seem fine to me)... any advise??? thanks.
 

·
Premium Member
Joined
·
1,137 Posts
imported post

chilidawg wrote:
You Sir, have a stopped up return hole in your master cylinder, I personally have no experience with your master cylinder but I can assure you that there will be someone along soon that does.
 

·
Premium Member
Joined
·
250 Posts
imported post

I am wondering if the piston inside themaster cylinderis returning all the way back so the small bleed hole is uncovered to let the fluid drain back into the reservoir? The book said that the brake clevis measurement to the first mounting bolt hole center to center on themaster cylindershould be 100mm. I am thinking that something is sticking and not letting the piston returning all the way back. It could be the shaft that goes through the frame that the brake pedal slides onto that is sticking. I was wondering if you could take the clevis pin out the next time it locks up. This would let the piston come all the way back in the master cylinder. Just a thought I have. Hope it helps.
 

·
Registered
Joined
·
2,795 Posts
imported post

So far you've isolated the following items:
1) Front brake line and caliper (disconnected)
2) Rear brake caliper (replaced)
3) Rear master cyclinder (replaced)

The only thing remaining unexamined, is the rear brake line... I'd suggest replacing that; or try Isolating it (by detaching it, as you did with the front brake line) to test.
 
1 - 20 of 33 Posts
Status
Not open for further replies.
Top