Losing brakes on 87 Buick GN

Every now and then my brake light pops on and I lose my power brakes so when I have to slow the car down I have to step on my brake pedal as about as hard as I can. This obviously is dangerous especially when I opened this car up some on the parkways.

I'm guessing my Master Cylinder is starting to go. Could I be right??

What else can cause this problem??

Thanks

Does the pedal go down farther than normal when this happens? Is the pedal harder to press than normal? Are you losing fluid? Are you able to pump the pedal and get back some pressure? Explain your symptoms to your local parts counterman and they should be able to advise you. You may want to use one of the higher end parts stores like NAPA, most of the chains stores really cannot help. There policies wont allow it and the employees are very often lacking meaningful experience.

Usually it is the accumulator (the thing that looks like a round ball), if the pedal is extremely hard to depress quickly, such as at a stoplight.

The accumulator is expensive, usually around $100. I would recommend you get a remanufactured brake unit, but those prices have skyrocketed lately.

what else is new. these brakes always go, iv heard more complints about these brakes then anything else. you can replace the unit which is what i did. apx 600$ total, and so far theyv been great. most people who have had these cars much longer than i have recomend the power brake conversion like the tta has.they said they replaced their powermaster every 5 or so years then made the conversion whith no problems after years. the tta's suposedly rarely need major brake work done. poston sells the conversion kit, but its pretty expensive apx 900$. my brother just got one on ebay for 150$ and it works great. if i had to guess, i would agree it is probrably the accumulator.

I would keep the powermaster system over vacume brakes anyday. as far as holding boost and emergency stopping the vacume system can not hold a candle to the powermaster unit Prople who pay 600 bucks for a powermaster don't know how to buy them. Go to autozone and tell them that you need the powermaster motor it should be like 220 bucks or something like that and it comes with everything including the good accumulator (The one with the yellow writing on it.)

The trick with the powermaster is to keep clean fluid in it. (I accually change my fluid once a year at the end of the summer.)

I think I have an accumlator in my workshop somewhere. The one with yellow writing on it. If I find it and it works (Ill take it to work and check the nitrogen charge on it.) If it checks good and you want it PM me and we could work something out.

Andy

My car's light comes on sometimes when i press the brakes real hard....but does not get harder to stop....do i have the same problem

i also just started to have this problem with the brakes on my 87 gn its like the key is off when it is on. Is there a way to test the accumulator and is their any special tricks to putting a new one on . any info would really help thanks. ( it had a remanufactured unit put on before i bought it about 5 years ago at midas $650 ) i dont need brakes that bad. lol.

Usually it is the accumulator (the thing that looks like a round ball), if the pedal is extremely hard to depress quickly, such as at a stoplight.

The accumulator is expensive, usually around $100.

didnt someone on one of the forums have the GM number for the old style accumulator ball?? i'm thinking it was lots cheaper then the yellow stripped new style. if you can get 2 or 3 for the price of the new style and have those two last as long or longer then 1 yellow strip one then it may be worth it. it is so easy to change out these accumulators at the first sign of trouble (brake symptoms and the dash brake light)

is it usually just the accumulator?or is it also the electric motor too. I am going to jump the motor some time soon. thanks.

I switched to vacuum a few years ago and haven't looked back. I didn't like the idea of losing my brakes everytime the fuse would blow. Very easy swap and MUCH cheaper than even the cheap PM's from Auto Zone.

thanks but i think i would rather stay with the original setup (just like that idea better). dont the vacum brakes react different with the turbo?

Yes, they do react differently. They actually work. Just keep in mind that when the sinlge 25 amp fuse blows you have 2-3 pumps of the pedal before your brakes are GONE. Ask me how I know. Very scary when you go to stop and you can't, all because of a little 25 amp fuse. Also keep in mind that every sinlge 1989 Turbo Trans Am had vacuum brakes. The reason? They learned a thing or two about the Power Master units. I switched mine from PM to vacuum in about 1 1/2 hours. It was very easy and cost about half of even the cheapest PM units from the parts store. Which you must keep in mind are REBUILT units and look like crap. All spray pained black and just ugly. Some might not worry about looks but I like my car to look nice. But, to each his own.

i am starting to be convinced where would you go to get one of these units (i like the 1 1/2 hours idea)thanks.

Here is what I did: Went to the salvage yard and bought a booster and brake pedal from a N/A Regal. You will need the new pedal because the mounting hole is a little higher on the N/A cars and the booster won't bolt up to the Turbo car pedal. You could always drill a new hole but it just seemed easier to change the pedal. All you need to do is remove the rod from the booster that attaches to the pedal and one bolt. Very easy. Then you will need a new master cylinder from a 1987 Regal and about 2 feet of vacuum hose for the booster. The last thing you will need is a vacuum block from Kirban's or most any other Buick vendor.
I went a little extra on mine and re-cad plated (with the spray paint kit) the junkyard booster to make it look original but you should have a very easy time finding one that just needs a little cleaning. I mounted the master on the booster, mounted the booster to the car, changed the pedal, changed the vacuum block, mounted the hose and hit the road. I didn't even have to bleed the brakes because when I was done, I just barely pushed the brakes a couple times and it bled the small amount of air out of the fittings.
The new billet vacuum block:$25
New master cylinder :$20-25?
Junkyard booster & pedal:$10-15
I have pics if you would like to see how original it looks when you are done. Like I said, this was very easy to do and the peace of mind priceless!

There's no question that going to the Hydro Boost system will mitigate the on-going problems with the accumulators having an apparent finite life (87 GN, bought new in 87, and my 4th accumulator replacement). However, note the earlier comments, which are right on the mark: There is no comparision in braking power between the Power Master and Hydro Boost - the former wins hands down. The second point about keeping the fluid clean (which is a real pain in the ass to remember) is imperative to improve the accumulator's service life. Finally (my point) is that accumulator's, in my experience, go out fairly infrequently. When they do, head someplace like eBay and you'll probably find one for 1/2 the going retail at GM or wherever. I just got my latest replacement there for $70.

Good Luck whatever your braking systems decisions might be, but that Power Master, when it's maintained, is a beauty!

I'm talking about the vacuum brakes, not the hydro-boost. Big difference. The hydro-boost runs off of the power steering pump. A completely different animal.

thanks i will probably go with the powermaster

Just so everyone knows, Dennis Kirban just got his hands on some NOS accumulators. If anyone needs one he is the man to call! :2cents: