One ton xj brakes issues!!!!

Slut99

Slut99

Member
Joined
May 17, 2013
Location
Winston-Salem, North Carolina
Alright the jeep is a 97 xj all disk brakes 14 bolt and d60 and the jeep had a corvette master cly on it and the brakes would work if you pump them up. Well I bled the brakes and still the same thing... Well I bought a brand new XJ OEM master cly and put it on bled the brakes again.. They are a tad better but still the same thing....

What's the issue??????
 
Are you bench bleeding the master cylinder before installation, and does the ABS system need bleeding if you have one?

If you have floating calipers, make sure all if the calipers slide on the slide pins. Stuck slide pins can sometimes make the brakes feel spongy because the caliper assembly will flex (sometimes the rotor will flex sideways as well) instead of sliding and can't make proper contact across the rotor.
 
78 Mercury Grand Marquis master cylinder with four wheel discs.
 
drkelly said:
78 Mercury Grand Marquis master cylinder with four wheel discs.
Click to expand...
Second that and make sure the calipers are on the correct side, bleeders up.
 
Slut99 said:
I understand that it might not be able to push enough fluid at once. But I don't think that's my issue. When I say pump them I have to pump them 5-8 times before getting a solid peddle...
Click to expand...
This is the problem and the result. Volume vs pressure problem. You need much more volume to get pedal "pressure". You can be bled properly but still not get good pedal. You need to displace more fluid in one stroke. Your area has increased with the calipers and the size of the related resevoirs (each caliper bore).
 
Either of the ones suggested will work. I have personally run the 86 E350 master on both a 95 XJ and a 89 MJ with Dana 60/14 Bolt combo. Each time I reused the stock booster.
Pedal feel was stock and I could lock up the tires no problem.
 
It happens sometimes, any chance a caliper is upside down and you have trapped air someplace?
I use a pressure bleeder myself. Works like a champ
 
Jody Treadway said:
It happens sometimes, any chance a caliper is upside down and you have trapped air someplace?
I use a pressure bleeder myself. Works like a champ
Click to expand...


All the bleeders are on top of the calipers.
I always bleed brakes with a hose coming off the bleeders in a cup of dot3 that way it pushes air out and sucks fluid back up.

I'm very confident that they are bleed up to par.

And like I said why would it act the same with a UPGRADED master cly????

That's what leads me to believe it's not a mc issue???
 
I used a 78 gand marquis Mc for a while but with o lyrics fair results. The jeep would stop, but not like a jeep with one ton brakes.

I swapped to a 69 camaro mc, moves the lines to driver side for easier access, and is all cast iron unit.

I also had to make a longer adjustment bolt for the push rod. Getting that bolt adjusted properly allowed me to set just how hard or soft the brake feel is.

What I learned, is that my push rod was too short with the grand marquis MC, but I never properly adjusted it.

Moral of the story, adjust the pushrod bolt, and you may have to make or buy a longer one.

I also swapped to the cheapest part store pads, as they have the softest compound, that offer more friction cold.
 
Mac5005 said:
I used a 78 gand marquis Mc for a while but with o lyrics fair results. The jeep would stop, but not like a jeep with one ton brakes.

I swapped to a 69 camaro mc, moves the lines to driver side for easier access, and is all cast iron unit.

I also had to make a longer adjustment bolt for the push rod. Getting that bolt adjusted properly allowed me to set just how hard or soft the brake feel is.

What I learned, is that my push rod was too short with the grand marquis MC, but I never properly adjusted it.

Moral of the story, adjust the pushrod bolt, and you may have to make or buy a longer one.

I also swapped to the cheapest part store pads, as they have the softest compound, that offer more friction cold.
Click to expand...


Man this is what I think my issue is...
When I took the corvette master off it had a "custom" push rod and it was way to long for my stock MC so I cut it down and slapped it together.

How do I know what the proper length would need?????
 
Slut99 said:
Man this is what I think my issue is...
When I took the corvette master off it had a "custom" push rod and it was way to long for my stock MC so I cut it down and slapped it together.

How do I know what the proper length would need?????
Click to expand...

Measure.
Measure from the mounting surface of both the booster and the master to see how recessed the push rod needs to be. Allow just a hair of clearnace with the pedal released.
You can adjust it out until the master doesn't sit flush against the booster and then back it off until it sits flush.
 
Jody Treadway said:
Measure.
Measure from the mounting surface of both the booster and the master to see how recessed the push rod needs to be. Allow just a hair of clearnace with the pedal released.
You can adjust it out until the master doesn't sit flush against the booster and then back it off until it sits flush.
Click to expand...


Thank you I will try that and see what happens.

I'll let you know the results
 
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