Jump to content

Blown Brake Booster?


Recommended Posts

Short story- Driving my 87 home from work yesterday and slammed on my brakes because someone cut me off and then slammed on their brakes to stop at a yellow light. I had all 4 tires locked up skidding sideways... Ever since I've had to pump the pedal 2-3 times for it to have decent stopping power. I checked all the lines and cylinders for leaks and couldn't find any, there haven't been any puddles or drops anywhere either. Could I have blown the vacuum seal inside the booster? It makes a hissing sound louder than usual but I still have working brakes after pumping the pedal 2-3 times! I need to figure this out because now I have 2 Jeeps I can't drive :(

Link to comment
Share on other sites

Check your hard lines, especially over the gas tank, and check your rear height sensing valve. It was a panic stop just such as you describe that exploded the height sensing valve in my '88 MJ.

 

The result is that you get a low pedal because the rear circuit is blown and you are now stopping entirely with the fronts.

Link to comment
Share on other sites

I checked everything from the booster to the rear wheel cylinders and there's no leaks, 99% of the truck is rust free so none of the lines are rotted. I did the chilton brake booster test and seems like my booster is shot, I have a 99 XJ booster and master I can modify to fit so that'll be this week/weekends project..

Link to comment
Share on other sites

I checked everything from the booster to the rear wheel cylinders and there's no leaks, 99% of the truck is rust free so none of the lines are rotted. I did the chilton brake booster test and seems like my booster is shot, I have a 99 XJ booster and master I can modify to fit so that'll be this week/weekends project..

You stated that there was additional 'hissing' after the panic breaking.......that was the tell tale......but you got it figured out anyway.

 

I replaced my booster with a new stock one last year and I wish I had done the later model upgrade.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share

×
×
  • Create New...