Buy Now | Log In | ALLDATA Corporate Site |
Back To Home Page
Log In To Your Subscription
Go To ALLDATA Back Home
Buy A Subscription! Back Home About ALLDATA Information View Sample Vehicles Read Testimonials View Factory Service Bulletins and Recall Titles Contact Us
Dowload Our Navigation Chart
February 2015: New vehicles added including 2014 GM.
• View New Vehicles
October 2014: Release of 2013 along with initial 2014 Vehicles
• View Vehicles
View All News and Updates:
• Go To News
Tech Tips
  Read All Tech Tips

ALLDATA Tech Articles Are Updated Weekly
• View All Tech Articles

  Dodge Durango: Brake Pulsation Problems In Paul's Durango
• Read Dodge Article
Fixing A Smelly Audi Audi Tech Tip: A4 begins to Smell caused by a Faulty Hose Composition
• Read Audi Article
Why Do You Need To Change Your Timing Belt? Why Replace Your Timing Belt
• Read Belt Article
Jim Grant Tech Tips Jim Grant Tech Tips
A collection of helpful articles based on reader submissions
Home >> Featured Tech Articles >> Go Back
  Jim Grant's Tech TipsJim Grant's Tech Tips
Below is a collection of Jim Grant's Tech Tips sorted by Vehicle Make. These Tech Tips were answers to questions submitted to Jim by users over the course of many years.
If you have any questions, please feel free to email us.



Lincoln - Mercury
  Jim Grant's Tech Tips

96 GMC Jimmy, ABS / Hissing Brake Pedal
Q: My '96 Jimmy has been in for the first ABS recall and since that time, the brakes have gradually become less effective. When applying brake pedal, a hissing sound comes from the area of the pedal. If I pump the brakes once, all brake function disappears. I have no ability to stop at all. The vehicle is scheduled for the second recall in a few days and I want to make sure that I won't be misled into replacing other brake parts. The 2nd recall involves replacing a vacuum switch on the transfer case, and the hissing in the pedal certainly sounds like a vacuum leak. What would cause the hissing, and also what would cause the brakes to fail altogether after pumping just once?.....Rich

A: The problem youíre describing and the recall for the brakes are not likely related. Why? One recall is for a change in the Anti-lock Brake computerís program. The other involves a switch that tells the Anti-lock Brake computer when the vehicle is in 4 or 2 wheel drive. Your condition seems related to the power brake booster. The power brake booster makes use of engine vacuum to provide power assist when braking. If the vacuum supply to the brake booster is low the effort required to stop the vehicle greatly increases. Iím talking the kind of push that causes your leg muscles to spaz just to stop the vehicle. Most brake boosters have a vacuum reserve that is good for 2 to 3 brake applications; anything less thereís a problem. If the engine is not running correctly the amount of available vacuum to the power brake booster is reduced, which reduces braking ability. This can be checked easily with a vacuum gauge. If vacuum supply is low then thereís a problem with the engine. If the vacuum supply is good then the vacuum hose, vacuum check valve, or brake booster has a problem. From your description you have a basic brake function problem that the recalls are not likely to correct. Be sure to check the basics of the power brake system first.

Have any Questions About Please Email Us
Buy Now | Log In | About | Sample Vehicles | Testimonials | Join Affiliate Program