Eric90XJ

I've been having vacuum leak problem, i blocked off the EGR system, seemed to have brought my idle down some but not all the way. I was talking to the guy over at AutoZone and he seemed to know what he was talking about and garunteed my Brake Power Booster was the source of my problems. The brakes work horribly and I have to stomp so hard on the pedal to get them to work and when you press the pedel with the engine off you hear a noise like air rushing. Any one else support this? I'm fixin to go ahead and order a new one. My other question is, do I need the new cylinder too? Is there a way to tell? My experience with brakes is limited. Thanks for the response.

mark's91-XJ

yep i had the same problem last week. if you can hear air coming from the booster its bad. the leak will through off the computer and cause bad idle problems. as far as the master for 12 bucks more at auto zone you get a
new one , might as well while you have it out!

Eric90XJ

Sweet, sounds like im on the right path. Do I need to check any lines or anything or would it be the pressurized cylinder chamber itself that has the leak?

mark's91-XJ

when you replace the boster it will fix the vac leak, if you do the master too remember you will have to bead all the break lines at the wheel cylinders RR to FL. you should check them as well. peal back the rubber seal and see if you see break fluid ,if so replace it 9 bucks auto zone again lol

Whackmaster

I had the same problem...Booster fixed it

Willys55

You don't have to bleed the brakes at the wheels cylinders or calipers. If you are replacing the master cylinder you bench bleed the master first. When you install it as long as you don't open any bleeder screws the fluid in the lines will remain and all you have to do is re attach them to the new master. Air does not enter the lines when you remove them from the master unless the bleeder screws are opened first. BTW, a quick test of the booster leak problem , remove the check valve from the booster and plug the line. Start the engine and see if runs normally, idle and all. Re attach the booster check valve and restart the engine, after 30 seconds turn off the engine and pump the pedal 5 times , the brake pedal should get rock hard, after pumping the peddle 5 times while still holding the pedal down restart the engine, if the booster diaphragm is working correctly the pedal should drop to the floor a couple of inches. From what you described the booster sounds like the problem, and many companies offer the booster and master together as a kit.