NEWBIE HELP! WTF is a brake switch

[TRYMY231S]

NEWBIE HELP! WTF is a brake pressure switch

Well last night I'm coming home from my friend's house and the brake light comes on. No big deal I thought - until I hit the next red light and I couldn't stop!!! I talked to one of DeQuick's boys and they said it was a brake switch? The brake fuse is blown if this help out. Also, the whole brake unit looks new (the car has 140,000 and this is the only real clean piece under the hood). Where can I find one of these brake switches? I don't care about price cause this is my *second* broken car as of right now (the trans in my GTP went bye bye) and I need something to drive. HELP!!!

Thanks in advance,

 

[Turbo Brian]

Start by replacing the 30A fuse and see if the problem recurs. The fuse powers the brake pressure pump. If the pump continues to blow fuses, chances are the brake pressure pump has excessive draw (bad pump motor) or possibly is running continuously, which might be caused by a bad pressure switch.

There are some new pump motors available through this board, but the pressure switches are strictly dealer items. They run about $130 last time someone posted a ballpark price.

 

[TTA197]

Brian, I would convert over to vacuum brakes. I had my switch go out on my GN along with the accumulator. I bought my switch new at the dealer for $180 only to find out I also had a bad accumulator. So I decided to convert to vacuum brakes then and love it. If you don't want to convert to vacuum , I'll sell you my switch. Nicholas.

 

[texasturbo]

brake switch

If the switch is bad, it will cause the motor to run excessively, thus an over pressure situation will occur and cause excessive current draw from the motor and blow the fuse. Try (with the key off ) pumping the brakes about 10 to 15 good times to release all the pressure out of the system. Replace the fuse.
Then in an area where you can hear the pump motor running, just turn the key on. You should be able to hear it run, slow down as it builds pressure and kick off when sufficient pressure has been reached to trip the pressure switch on top of the brake assembly. If it continues to run or intermittantly continues to run, then the brake pressure switch is probably bad. If when the key is turned on the fuse blows immediately, then good chances are the pump motor is bad or there is a wiring issue somewhere. Hope this helps.....

 

[WIKEDV6]

Hey where in Chicago are you, If you want to try changing the switch, I may have few laying around or you could buy the WHOLE new(rebuild) unit for around $179.00 from Autozone w/ life time warranty.

Good luck
Prasad

 

[Chuck Leeper]

Brakes or lack of??

Look behind the M/C assy. There's a switch there. Is it gray or black? If it's black, there's a GM recall on it, and the local GM dlr should replace it for free. [They are well OVER $100 if you buy it.]

MOST likely, the motor is FUBAR. To see if the sw. is at fault: replace the fuse. Turn the key to ON. The pump should cycle for a few seconds and turn off. If it continues to run, then the sw. is most likely gone south. If it turns off OK, then it's usually the motor.
Being the assy is clean and looks new, it's probably a rebuilt Powermaster assy from someone like Cardone, Autozone, Pep Boyz, etc. SOME WORK, SOME DON'T!!

WARNING!! Do NOT remove the lid and start the engine and stand on the brakes!! You WILL spray your paint w/ brake fluid!!
DO ALL testing w. the lid on and snapped down in place.

ALL disassembly has to be done AFTER you de-pressurize the system. To do this, key OFF, pump the pedal AT LEAST 10 times. This bleeds the PSI off the accumulator. This is important as there's several 100 psi in it and it will hurt you and your paint job, if not done.
The system should have the fluid changed every 2 yrs. Now's the time to do it.
HTH,

 

[Lee_Burough]

Troubleshooting Powermaster Brakes

When my TR's brakes were acting up, I found this GNTTYPE page for a complete reference on general brake issues:

http://gnttype.org/techarea/brakes/brakespage.html


For detailed steps in troubleshooting Powermaster Brakes, go here:


http://gnttype.org/techarea/brakes/PwrMstr.html

Good Luck

 

[TRYMY231S]

Thanks for all the responses guys. I'll try these ideas when I get home. WIKEDV6 - I work downtown, live in the western burbs, and hang out on the south side. I'll be at US 41 for Street Car Chaos tomorrow if you are going. I'll buy the switch from you if you have one. I'll try the fuse first, but it's never an easy problem with me.

EDIT: typos