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Powermaster Brake Dangerous Defects

a_l_hubcapsa_l_hubcaps Member Posts: 518
edited April 2014 in Pontiac
I am a high school student in NJ. I drive a 1986 Pontiac Parisienne in near mint condition, well maintained, with 41,700 original miles. My problem is that the stock Powermaster brake system is dangerously defective. I experienced a total brake failure on a major highway, which could have caused a serious accident. The car has been in the shop four times with brake related problems since I bought it in 3/00. I have spent over $500 replacing brake parts. I found that the Powermaster system is widely known to be defective; there are loads of consumer complaints to NHTSA. Two components were recalled in 1990, but GM refuses to give me the free repair because my VIN number was not included in the recall, although my car does have the defective parts (my mechanic checked). These brake problems are a potentially dangerous situation, because the brakes seem to be fine but will suddenly fail or behave strangely with no warning. I have no way of knowing if my car is going to stop properly when I push the brake pedal. GM should be held responsible for this shoddy quality. My dad owns a 1998 Oldsmobile Intrigue and it is a quality nightmare, too. From what I hear, Chrysler and Ford are even worse. Buy a Toyota!

- Andrew L


  • racer_x_9racer_x_9 Member Posts: 91
    Do you have the maint records for the car? If the brake fluid was never changed and the system flushed, this could take its toll on the braking system after 15 years of use.

    Brake fluid goes bad as a function of time, not miles.
  • turbogn1turbogn1 Member Posts: 1
    You are not alone. GM used the Powermaster brake system on the 86 full size wagons and the 86 and 87 Buick Regals with the 3.8L SFI Turbo engine (Grand National).

    There are two recalls on this system. The first is easy to check to see if it's done, GM recalled the pressure switch on the top of the powermaster. If it is black in colour, then you need to have it replaced by the recall (free of charge). If it's grey, then it has already been changed. There is also a proportioning valve invovled in the recall.

    Over time, the Powermasters tend to develop numerous other problems with age. If it's not the pressure switch, it might be the accumulator on the side. Sometimes the pump will stop working all together. And finally, it's possible that the master cylinder will eventually start leaking pressure and need to be rebuilt.

    On the turbo cars, it's nice to have the powermaster system, as when the engine is under boost, you have no vacuum for power assist to the brakes (useful for racing at the track). On the wagons however, there is no real need for the powermaster.

    Your best bet is to convert to vacuum brakes. It's fairly easy to do... all you need is a brake pedal and master cylinder out of another GM wagon in the wrecking yard, and it should just drop right in. Several Grand National owners have done this already. For details on the conversion, go to the website and look under the technical archives:


    Replacing the entire powermaster with a new unit would likely get rid of your problems for another 10 years as well, but they are extremely expensive ($800 or more).

    Before you do the conversion, check the pressure switch and accumulator. If that's all the problem is it will buy you time until something else on it breaks. The switch is covered under the recall, and the accumulators are about $60. Everything else on it is very expesive, the pump is almost $300.
  • joe3891joe3891 Member Posts: 759
    Will a junk sell anyone used brake parts,i thought there is a federal law prohibiting it.
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