10er

Rank nooB here. I've owned my 96 S-10 with only about 140k for a few years. Today the brakes required lots of pressure, with little stopping power available. The brakes worked, but took a lot farther to stop. My experience is that this is a failure of a brake booster in the power brake system, but I can't figure out if the truck has power brakes. What should I look for?

tech2

its gotta have a vacuum booster. look for a big round metal bowl shaped object bolted to the firewall, behind the master cylinder. check the vacuum line to the booster.


to check the booster; with the truck off, press the brake pedal multiple times to deplete the vacuum reserve. hold the pedal down on the last application. start the vehicle. if the booster is working it the pedal should go lower to the floor.

10er

Thanks, tech2. Pulled the line off at the booster this pm and the line has good strong vacuum when I capped it with my thumb. I also did your pumping test and there was no difference in pedal pressure after starting the engine. In addition, inside the cabin I can hear a hissing sound when the pedal is pressed, so I'm guessing vacuum is leaking from the back side of the booster. I suppose my next step now is a trip to Rock Auto...

Your help is much appreciated!

10er

Looking at the FLAPS offerings, can the booster be replaced without opening the hydraulic side of the system, and is this difficult? Driving around a bit with the failed booster, the brakes themselves feel rock solid once I got used to the pressure required, so I'd rather not have to bleed the brakes if I can avoid it. It looks like the M/C bolts onto the outside, booster bolts to firewall, brake pedal bolts to booster from inside. Am I missing something? Also, are the reman units OK or do they fail quicker than a new one?

TIA!

tech2

sounds like you are headed in the right direction. I have not done one for this model. I would definitely try to remove the booster without disconnecting the fluid lines.
If there is a big difference in price buy the cheaper one. Its hard to know reliability of such things.

10er

You have been a great help, tech2! I would still be scratching my head without your help. Thanks again!