'81 Master cylinder rebuild problem


Information and questions on GL1100 Goldwings (1980-1983)
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dawgout81
Posts: 96
Joined: Fri Apr 22, 2011 5:53 pm
Location: New Ulm, MN
Motorcycle: 1988 1500

'81 Master cylinder rebuild problem

Postby dawgout81 » Mon Feb 13, 2012 6:32 pm



Last weekend I got all my brake cylinders rebuilt, including the master.

However, after putting the master cylinder aside on the work table after rebuilding (while rebuilding the rear cylinder, calipers and installing new stainless brake lines), the piston in the master cylinder will not move in and out anymore after sitting for two days.

Does anyone have any suggestions:
1. as to how this happened, it worked fine right after rebuild?
2. what to do about it now?



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seabee_
Posts: 494
Joined: Sun May 29, 2011 8:17 pm
Location: sterling heights, mi
Motorcycle: 1985 Honda Goldwing GL1200
117k miles
1977 Kawasaki kz400
1978 Suzuki GSXr750
1980 Kawasaki GPZ400
1975 Honda CB360T

Re: '81 Master cylinder rebuild problem

Postby seabee_ » Mon Feb 13, 2012 6:54 pm

During the rebuild or while it sat on the table, did any petroleum based liquids/oils come into contact with the master cylinder? The thing with the rubber components, seals-cups-boots, is that they will swell when they come in contact with petroleum products. They can work fine at first, then the swelling starts. That's a possibility. If this is the case, spray the master cylinder down with brake cleaner and see if it comes apart easier. Then clean everything real good(probably a few times) and put back together.

Did you use anything on it while putting it together? Did you put brake fluid in the master cylinder while it sat on the bench and what type?
Let us know if you get it fixed.
Paul
CE1 Navy Seabees/RET
1981 to 2002
ASE Mechanic

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dawgout81
Posts: 96
Joined: Fri Apr 22, 2011 5:53 pm
Location: New Ulm, MN
Motorcycle: 1988 1500

Re: '81 Master cylinder rebuild problem

Postby dawgout81 » Mon Feb 13, 2012 7:41 pm

I used ATF to lubricate the rubber seals all around.
Would that cause the swelling?

I am going to wait to try and fix as it will be until Thursday when I get a chance to put it all back together and bleed the system.

The cylinders were cleaned with brake cleaner and looked good and the pistons and seals are all new.

The brake cleaner was Gunk brand (non chlorinated).

User avatar
seabee_
Posts: 494
Joined: Sun May 29, 2011 8:17 pm
Location: sterling heights, mi
Motorcycle: 1985 Honda Goldwing GL1200
117k miles
1977 Kawasaki kz400
1978 Suzuki GSXr750
1980 Kawasaki GPZ400
1975 Honda CB360T

Re: '81 Master cylinder rebuild problem

Postby seabee_ » Mon Feb 13, 2012 8:48 pm

The ATF is possibly the culprit. Some ATF's contain a petroleum-based mineral oil in the mix. If it was in the ATF, then that will cause the swelled seals. You will need to clean it out the best you can to get it apart. Then you will have to try cleaning the components with brake cleaner. when putting it back together use brake fluid or non-petroleum lube to ease installation. I use silicon brake lube when I work on brakes. If you can't get the master to work, you might need new seals.
Paul
CE1 Navy Seabees/RET
1981 to 2002
ASE Mechanic

raycw
Posts: 127
Joined: Wed May 19, 2010 11:02 pm
Location: Jackson, CA
Motorcycle: 88 GL1500

Re: '81 Master cylinder rebuild problem

Postby raycw » Wed Feb 15, 2012 1:18 am

Your problem might be with the ATF but I also remember having a 'size' problem with that year 1100. Even though you might order the ABSOLUTE CORRECT PART NUMBER…. HONDA SENDS THE WRONG PART.

I wish I could help with what number is the correct one but just that there was a problem and it was Honda's problem.

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RBGERSON
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Location: SCOTTSDALE, AZ
Motorcycle: 98 SE GL 1500
had every year from 75 to 83

Re: '81 Master cylinder rebuild problem

Postby RBGERSON » Thu Feb 16, 2012 9:03 am

let it sit for a few days the swelling will go away..usually..


HAD LOTS OF GOLDWING 75-83
NOW INTO 1500'S..RIDING A 1998 SE

FAIR WINDS,
RB


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