I have a '91 Chevy Suburban, 5.7L 1500, 2 wheel drive, AC, PW.
One day my power brake went out abruptly. One second I had power brakes, the next they were gone. I can still brake, but the pedal is extremely hard to depress.
I checked to see if I had vacuum, and I get strong suction from the line that goes directly into the booster. Has my booster gone bad, or is this possibly a master cylinder problem?
Thanks in advance for any assistance!
Mark
Mark,
With the vehicle OFF, pump up the brakes till you get a really stiff pedal. Pushing down on the pedal as hard as you can, start the engine. The pedal should drop a few inches. If the pedal don't drop, the booster is shot.
Doc
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How about the check valve in the vacuum line that feeds the booster?
Sounds like the booster to me, but you can easily check the Check valve. Just pull it off, Suck on one end and you should get flow, try sucking on the other end and you shouldn't get anything. Those things rarely fail. Are you getting any Vacuum Noses inside the truck? Say you step on the peddle just a little and you start hearing a vacuum leak(While the truck is running) Then it's BAD for sure.
Yep, that's what I got!
Mark
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