89Pioneer

I got in the Jeep today and the brake pedal was hard as a rock and I have to give it all I got to get any brake. Feels like when you pump the brakes with the engine off. That's how it is now, with the engine running. It has ABS and since I bought it the check antilock light has been on and whenever I brake there would be a pulsating/vibrating noise. Anybody have any ideas?

robertj

Sounds like your vacuum brake booster could be bad. You really should get your brakes serviced if you've been driving around with an ABS light on and pulsating in your pedal if you can't work on it yourself; otherwise, you need to lift it up and get to work. The pulsating is probably the fact that you need new rotors or need to have them turned. While you're there it'd be a good idea to inspect the pads, calipers, shoes, drums, and cylinders. With a Jeep that old it'd be a great idea to flush the fluid as well.

89Pioneer

I thought ABS didn't use the power booster and that's the difference between ABS and power brakes. Is the big ball thing next to the master cylinder the ABS pump does anyone know? I hesitant to use my haynes manual due to it calls for the wrong bulb type to go in the license plate. Dont know how off it is on other things.

robertj

ABS and power assist have absolutely nothing to do with each other, and I doubt there are many ABS systems out there without a brake booster. If you're talking about the big round vacuum canister behind your master cylinder, that would be your brake booster.

Metmknice

ABS has NO effect on normal brake operation.

89Pioneer

What would cause the brakes to get so like they are now? Master cylinder? or booster? is there a way to check what is bad?

robertj

I DIDN'T say that they did, but it's obvious to me that the OP has let his brake problems stack up. I was just trying to make a point that he should consider getting it serviced.

Thanks for your contribution to the thread. You might try actually pitching in and helping next time instead of trying to put words in my mouth.

robertj

As I told you before I think the booster is the problem.

89Pioneer

People are funny on here. Any way, I bought this Jeep the day after turkey day. It had the noise when I bought it, but the pedal was fine. This just happened a couple of days ago. I talked to a guy at the local brake shop and he said it was a dealer only type situation due to the upwards of a couple thousands pounds of vacuum in that ball. Is this true or is this something that can be done in the driveway?

offroadohio

There is no pressure in the brake booster when the jeep is not running. The FIRST thing I wold do is look to see fi the booster line didnt come unhooked. I would also inspect the check valve where the line hooks to the booster.

Either way a hard pedal is a booster issue.