Brake issue, please help

[Mike Z]

Had my new-to-me '87 GN out last night, taking first my fiancee (who is a Mustang girl, but really liked my Jiffy Lube car), and then my 15 year old son. During my boy's ride-along, we were doing a little acceleration testing. Car was pulling well, and then flattened off a little. We crested a small hill, and then I applied the brakes.

When I hit the brakes, the pedal was very firm. Thought that maybe a vacuum line came off (and did find one off a few minutes ago, which I fixed). Didn't help the pedal situation. Did some troubleshooting on here, and the 30 amp fuse is still good.

Any ideas on what to check next? I've only put ten miles on the car, it's too early to have a problem!!!

 

[mikestertwo]

Does the car still have the electric powermaster brake booster or has it been converted to vacuum?

 

[Mike Z]

Still has stock Powermaster.

 

[Mike Z]

Little more troubleshooting today. Pumped the pedal 10 times, removed the master cylinder cover, and fluid levels are adequate. Then turned ignition key on to listen to time to pressurize, but really couldn't discern sound of Powermaster motor because fan was on. Started and drove the car, and now it appears to be fine.
Guess I'll leave it alone until it malfunctions...

 

[REM3200]

Might want to keep an eye on your accumulator. They act like that when they go out. Very very hard pedal but not much stopping power. At least that's the way mine acted.

 

[outlaw7d9]

acccumulator bal is probably bad

 

[tzque]

Did you buy are car that sat around alot . If you did here is the first thing I would tell you to change .that is the front rubber brake lines. I had the same intial problem and then my brakes failed .I wasnt going to give the powermaster a second chance . I switched to vacuum still had braking issues .In the end my rubber hoses were bad which was causing the problems with my powermaster . this might not be your solution but it is a cheap place to start .

 

[Lee_Burough]

This is a link to GNTTYPE.org and their page of brake information....Look under 'Brake Mantenance' and find their link for troubleshooting, that is all you need.