Excessive brake pedal travel

I just finished gutting my XJ (1990 4.0 AW4 242 30 35) of it horrid Bendix 9 ABS and putting in a master cyl/booster from a 1996 XJ. Everything is great except I have excessive pedal travel. I have bled and bled and bled the system but the pedal seems to have a lot of travel until the brake hook up. Any suggestions?hasta

Do you have the right rod between the MC and the booster?

Don't take this wrong but I don't know you or your skills. Explain the exact steps you use to bleed the brakes.

I had horrible adjustment after the first swap, and it ended up being a bad booster out of the box. The second booster worked much better, I don't think I did anything different between the installs. Check the adjustment on the shoes as well, the have a good bit to do with the pedal feel.

Bleeding-- Order- RR,LR,RF,LF. Three pumps, open bleeder, close bleeder, lift pedal. repeat until all air is gone.

I am not sure about the rod... It is the one out of a 1996 XJ. I had to drill the hole at the end and grind a flat spot for the switch.

I am not so sure it is a bad booster. The booster does everything it should do. Check valve holds vacuum. Pedal sinks when engine is started with foot on brakes...etc

Sounds like you know what you are doing. My bet is that the rod is too short.

old_man said:

Sounds like you know what you are doing. My bet is that the rod is too short.

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Interesting. I was just searching for an answer to my problem that is roughly the same. Not trying to hijack, but maybe with my details we can figure this out for the both of us. Background: 1988 XJ non-ABS, swapped it out for 1996 booster from JY and 1996 master cylinder from autozone. Swapped it over and everything was great for a few days. After that, the pedal seemed to travel a bit more before the brakes would engage. I noticed a small leak from where one of the new lnes I made entered the prop valve. Turned out that the prop valve had a burr where the flare meets it. I replaced the valve, bled the brakes and drove out of the shop with a very hard pedal, with about an inch of travel, almost like the booster wasn't working. Waited about an hour and drove it home. On the way home I noticed that the booster was definately working, but the pedal had a lot of travel like it did before, but it will still lock up my 30's. I looked, and did not see any leaks. I was leaning toward the master cylinder due to the low quality of autozone parts, but I really don't know.

I don't think that the rod would be too short for either of us because I looked them over pretty closely and they were close. I am also ruling out the booster because it definately drops it when you start the engine. Adjusting the rears definately helps if they are out of adjustment, but mine are not.

To the OP, hope you get it resolved.

I think I will try adjusting the rears and see what happens. Thanks for the input! I'll keep you guys posted on what happens.

old_man said:

Sounds like you know what you are doing. My bet is that the rod is too short.

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How would you determine if the rod was too short?