Electric Power Brakes 1986 LeSabre RWD

[Bradley]

Does anyone know anything about the Electric Power brakes on 1986 LeSabre RWD? I have never seen such a system and It probabaly needs service - my "Brake" light is on, and the car has been ingnored by previous owner.
THanks, Brad

[BillK]

Brad,
The "brake" light normally, but not always, indicates a problem in the hydraulic system of the brakes.
If by "electric" brakes you are referring to the Antilock Brake System....it requires some special tools and possibly a scanner to properly service. If you are serious about servicing the vehicle yourself, the first purchase you should make is the factory service manual. They are sometimes available on E-bay and still available new. Expensive, but invaluable...I dont know how anyone can service a modern vehicle without it.

[TODD]

Bradley, this sounds like the PowerMaster brake system. It was only used on 85-87 Turbo-powered Regals and the 86 Electra/LeSabre wagons.

Instead of engine vacuum to provide power boost at the brake pedal, it uses an electric pump mounted under the master cylinder. This pump forces brake fluid into an accumulator ball on the left side of the brake assembly. As pressure builds up, a nitrogen-filled bladder in the ball compresses to store energy. As the pressure reaches about 675 psi, the pump cuts off.

As the brake pedal operates to stop the car, this fluid under high pressure is released a little at a time to provide power boost. As the stored pressure drops to about 400 psi after maybe 10 stops, the compressor comes back on to recharge the system.

This looks neat in the shop manual, and electrically it is very simple. The other brake system components appear to be regular items. The special Power Master items only take up 9 pages in the shop manual. Buick issued a good Service Bulletin in 1990 dealing with troubleshooting the PM system. The purpose of the bulletin was apparently to cut down on excessive parts replacement when mechanics service these systems. You are welcome to copies of what data I have on this system.

Someone asked a similar question on this site a few months ago on his 86 LeSabre wagon. There were no responses. It doesn't look like anyone here has lived with one of these systems. I would bet the Buick Grand National/Regal Turbo guys have taken these systems down to the last nut and bolt and know all the quirks.

I hate to send readers other bulletin boards, but the GN/Turbo sites are probably an excellent source of information. I don't have any specific boards in mind, but we can dig some up if you have trouble finding some. Good luck with this unique system.