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Old 08-26-2005, 09:43 PM
stizkidz stizkidz is offline
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Default help! serious brake problem!

Hello,

I just purchased an 87 GN, all stock with 82k miles. Everything on the car worls great, it is a wonderful car. Well, I have only had the car for a week and I am experiencing a terrible brake problem. The "power assist" part of the brake system seems to suddenly just stop working. Sometimes the brakes stop just fine while other times I will barely be able to stop. When it happens, the pedal gets almost impossible to push and it feels like there is absolutely no power assist. The brakes stay like this for a while and then all of the sudden (maybe 15 mins later) the brakes will be fine again. The "brake" light on the dash is NOT coming on at all. I checked the components and the pressure valve is gray and the accumulator has the yellow warning label just like they should be. I did notice brake fluid all over everything, ecspecially the powermaster assembly. HELP! I can;t drive the car like this, it is too dangerous.

Thanks.
-Ben
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Old 08-27-2005, 02:13 AM
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PaCemkr86 PaCemkr86 is offline
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Default Re: help! serious brake problem!

convert to vaccum brakes
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Old 08-27-2005, 01:22 PM
stizkidz stizkidz is offline
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Default Re: help! serious brake problem!

Is there some way to diagnose whether or not the Powermaster unit is faulty? Where can I purchase a new unit inexpensively? Thanks.
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Old 08-27-2005, 01:52 PM
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Lightbulb Re: help! serious brake problem!

Sounds like yours was overfilled or has a leak.

Inexpensively? Little chance of that at this time...

Start reading http://www.gnttype.org/techarea/brakes/brakespage.html

You can try calling your local Auto Zone / Advance Auto Parts / O'Reilys / NAPA / etc. and see what they have to offer. Don't think many or any carry the Cardone remanufactured Powermasters anymore. They may have the new Bendix units, which are not cheap. (But do not require a core - don't give yours up if you don't have to) Dealers still have them, but expect prices around $1300+. Some vendors such as Kirban's may still stock rebuilt units as well.

Cardone #52-9702 . Might try #52-9700 which is an '86 Caprice wagon and see if they have that. Just have to change the reservoir from your old one.

There is always the vacuum route...
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Old 08-27-2005, 06:32 PM
stizkidz stizkidz is offline
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Default Re: help! serious brake problem!

Based on the info I have read, it seems like converting to vacuum brakes would only take a little more time than replacing the Powermaster unit. Is this so? Can someone who has done the conversion give me a heads up or some pointers to make the swap a little easier for me, please. Can I buy the vacuum canister/master cylinder for 86-87 regals/monte carlo's only? I need to know so I know which cars in the junkyard I can scavenge the parts from. Is gaining access to the bolts under the dash very difficult?
Thanks,
-Ben
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Old 08-27-2005, 07:14 PM
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Lightbulb Re: help! serious brake problem!

You can use the entire setup from all G-bodies from 84-87 (and probably a bit earlier will work, too - but stick with these years). A rebuilt master cylinder is pretty cheap and worth considering. The vacuum booster may be a yard item. Much of the details are in the writeups I pointed you to. Note that getting the pedal arm and the check valve setup will be critical! For what a check valve costs, getting a new one would not hurt.

Getting at the bolts under the dash isn't hard. Not trivial, but not hard. Much easier that pulling yourself out of a twisted wreck.
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Old 08-27-2005, 08:23 PM
stizkidz stizkidz is offline
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Default Re: help! serious brake problem!

Do you have a picture of the check valve setup? I am having trouble picturing the whole check valve thing. Do I have to worry about any wiring issues? Finally, is it absolutely necessary to disconnect the speedo cable and if so, how difficult is this?
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Old 08-27-2005, 09:07 PM
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Exclamation Re: help! serious brake problem!

The check valve is the thing that the hose hooks into on the booster. See attached.

The speedo cable crosses over or under the booster that is on your firewall right now. It may not need to be touched.
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Old 08-28-2005, 08:16 PM
stizkidz stizkidz is offline
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Default Re: help! serious brake problem!

Ok, I gave this project a "test run" tonight to see if I could forsee any problems and I had to stop almost immediately. First I pulled the covers out from under the dash to gain access. Right away I noticed hundreds of wires in my way. I then noticed an even bigger obstacle, the steering column is right under the pedal bracket. I could not even see the pedal bracket bolts or even get my arm up there!!! How have so many people done this swap eailly with such an obstacle? There must be something that I am missing here. Please help, I am planning on doing this swap tommorrow, as I currently have no brakes!

Using:
http://www.turbobuicks.com/forums/at...achmentid=9540
as a reference, do I assume that the 4 bolt holes at the bottom of the assembly are the only bolts that I need to worry about? Are these the 4 bolts vsible on the firewall under the dash?

Last edited by stizkidz; 08-28-2005 at 08:38 PM.
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Old 08-29-2005, 11:49 PM
stizkidz stizkidz is offline
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Default Re: help! serious brake problem!

Ok, just an update:
I did the conversion today and it works great. I am happy as can be and would like to thank everyone for their help.
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