1998 With Brake Problems - Booster?

The 1998 XJ has recently decided to start acting up. The brake pedal is very hard to push, but still works. If I slam it with all my strength I can barely get the brakes to lock up. That being said, before the problem it was very easy to lock them up and the pedal was nowhere near as hard to push. I also hear a a shissing sound from under the dash. To quote another member from a thread I found while searching it sounds like "One PISSED off snake stuck in the dash." Seems like the brake booster is broken. Any thoughts suggestions?

If it is broken, the good thing is that I already have the newer model with the better brake system. I do not have ABS. All the writeups on how to swap the booster are abotu upgrading an older XJ to a new booster. How hard is it to swap out a brake booster? It seems to be easy, but I don't know what to bleed and that kind of thing. Can anyone guide me through it or give me a good link on how to do the swap? Thanks for the help!

It sounds like you have a failed booster, but here is the sure-fire test:

With the engine off, pump the brake pedal about 10 times, until it becomes rock hard, and does not move much. On the last pump, hold the pedal down firmly, then start the engine. As the engine starts, the pedal should sink further as manifold vacuum rises. If this does NOT happen, you have a failed booster.

Booster replacement is easy: Unbolt the MC, and move it forward as much as you can without bending/kinking the hard lines. Unbolt the booster from the inside of the firewall, and disconnect the booster pushrod from the brake pedal arm. Remove old booster, and reinstall new booster in reverse order.

I don't have to bleed anything?

I forgot to mention that I did that test earlier and the pedal did not sink.

There is a recall on the 98 brake booster/MC....

drewkeen said:

I don't have to bleed anything?

I forgot to mention that I did that test earlier and the pedal did not sink.

Click to expand...

IF you don't disconnect the lines to the MC, no bleeding would be needed.

I have a 91 with similar problems. My brake Pump on the passenger side firewall keeps pumping. I think the MC must have a leak. Any tips on how to test for a mc leak.

Thanks

Rich, thanks for the heads up. I called the dealer and of course Murphy's law is that mine was not one of the recalled units. I did however set up an appointment to have the airbag recall done.

Should I got with a booster from NAPA, a junkyard or some other place? I read that if I get a Napa one I need to leave the spacer out, is this true for my 1998 or just for peopel swapping them into the older models?

The brake boosters on the non-ABS XJ should all interchange between a 97 thru 2001. I would go for a late-model booster from a junkyard, as booster's generally don't go bad, at least not on a 2001 in a boneyard.

If that fails, try a reman from NAPA.