How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask HDGENE Your Own Question
HDGENE, Master Auto Technician
Category: GMC
Satisfied Customers: 5647
Experience:  Master Auto Technican
Type Your GMC Question Here...
HDGENE is online now
A new question is answered every 9 seconds

My 2003 GMC Sierra 5.3 has a Service brake booster warning

Customer Question

My 2003 GMC Sierra 5.3 has a Service brake booster warning light on I believe that I have a vacuum booster I ran the test that suggested in the Chilton Service book
Submitted: 1 year ago.
Category: GMC
Expert:  HDGENE replied 1 year ago.

Ok if it is a vacuum brake booster it will have a large metal vacuum booster behind the master cylinder,if it is a hydroboost system it will have power steering hoses going to the hydroboost unit behind the master cylinder. Pump the brake pedal several times and hold your foot on the brake and start the engine, if the booster is ok it should make the brake pedal drop while holding down on it

Customer: replied 1 year ago.
It is definitely a vacuum booster and I did the test you just described the test passed
Expert:  HDGENE replied 1 year ago.

And the light stays on all the time?