Hydro-Boost Leak between booster and master cylinder

Started by GulfCoastFighter0, July 09, 2009, 05:54 PM

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GulfCoastFighter0

I have an '80 Minnie Winnie on C30 Chassis.  It has the hydro-boost braking system, which has sprung a leak at the junction of the booster and master cylinder.  Looking at the repair manual, it seems that the only place that can be causing the leak would be the o-rings on the piston in the master cylinder.  Anyone have any tips or suggestions?  It seems simple enough to remove and replace the O-Rings, but I thought someone might have further insight.
1980 Minnie Winnie
1971 Bethany Citation 86
1971 Airstream Ambassador
NRA Recruiter

Froggy1936

Hi, You do know that there is both Power steering and brake fluid at this area, Which one is leaking  ?? Frank
"The Journey is the REWARD !"
Member of 15 years. We will always remember you, Frank.

GulfCoastFighter0

Quote from: Froggy1936 on July 10, 2009, 11:40 AM
Hi, You do know that there is both Power steering and brake fluid at this area, Which one is leaking  ?? Frank

Yes, and brake fluid.
1980 Minnie Winnie
1971 Bethany Citation 86
1971 Airstream Ambassador
NRA Recruiter

GulfCoastFighter0

I've had to order the seal kit online, as all my local parts houses can no longer get it?  Weird.  I was hoping to get a shakedown run in this weekend before our big trip in August, but maybe not!
1980 Minnie Winnie
1971 Bethany Citation 86
1971 Airstream Ambassador
NRA Recruiter

GulfCoastFighter0

Apparently no-one can get the right kit, so I bought a new Master Cylinder. The old fittings and lines were in bad shape and couldn't be removed from the old one, so I cut the lines.  I bench bled the MC, installed it, and replaced the front line without a hitch.  The rear line however, is being a pain.  I got the wrong size compression fittings twice (once my fault, another a misprint on the package), and I can't get my flare right.  It either cracks, or isn't large enough to actually seal!  The tranny lines weren't this difficult.  What a pain, all caused by a small O-ring leaking.  SHeesh.
1980 Minnie Winnie
1971 Bethany Citation 86
1971 Airstream Ambassador
NRA Recruiter

GulfCoastFighter0

OK, it seems this is becoming my personal blog.  Hope no-one minds (especially the mods LOL).

After getting everything right, I bled the system and everything looked great, no leaks, good pedal etc.  So I fired her up and hit the brakes a few times in the driveway before the test drive.  WOW, the hydro-boost put some pressure on the fittings and they ALL leaked.  So, I bought new lines with the factory flares (wound up being cheaper than all those fittings in the first place), and dang if all the connections aren't different sizes.  A few more trips to the parts store for adapters and I was in business.  Replaced the pads, cleaned up the rotors and checked for leaks.  No leaks, test drive and EUREKA, everything's great!  Drove down the highway just to celebrate.  What an aggravating job, but oh so satisfying in the end.  Now I can't load her up to go camping because it started pouring!  I'm heading out Monday regardless.
1980 Minnie Winnie
1971 Bethany Citation 86
1971 Airstream Ambassador
NRA Recruiter