ABS Replacement ??

[Christopher]

I know replacement has been covered before, but I'm trying to figure out some booster/master cylinder specifics. My Jeep is a 1990 with ABS. I have looked at various options for which booster/master cylinder to use and have some questions. There is the 1996 with the dual diaphram but I don't like the idea of the single plastic resevoir, I've lost lines before with similar setups and all breaks are lost. There are booster/master cylinder setups for 1988 & 1990 w/o abs but they have different part #'s and prices. Does anyone have any suggestions on which parts I should use or what the differnces are? Are there any other options available to have dual diaphram booster and a cast dual reservoir master cylinder? Any help or suggestions is greatly appreciated. Thanx

 

[Bones]

Anything is safer than the Bendix ABS. While the single res system is somewhat of a concern, I think the '96 has a divider in the res to help in this situation. As it stands if you lose a fuse to your ABS pump, you loose your brakes. Which is safer? I will take my chance with the plastic res.

One other option is the Navaho brake system. It is a dual diaphragm system that is a popular swap in some Jeep circles. I do not know what it would take to rig it up in a XJ.

I have done the swap from ABS to std single diaphragm brakes then to the dual diaphragm set up in my XJ. I would recommend the '96 set up. Grab the whole thing out of a salvage yard (including brake lines for templates) and the pedal assembly (ABS and non-ABS are different) and trash the ABS before it hurts someone.

If you haven't already read it here is a tech piece I did on my brake swap project http://www.naxja.org/html/techarticles/uninstall_OEM_ABS.htm .

Bones :skull1:
#6

 

[Christopher]

Is the '96 a bolt in swap or would it require modifications to the pedal assembly?? Does anyone know if there are any differences between the '90 & '88 and what they are??

 

[Bones]

Is the '96 a bolt in swap or would it require modifications to the pedal assembly?? Does anyone know if there are any differences between the '90 & '88 and what they are??

I would expect EVERY swap to require some pedal mods when going from an ABS to non-ABS. I even had to swap the pedal assembly going from a '91 ABS to a 91 non-ABS system. There were more mods to be done going to the non-ABS '99 booster when I installed it but had I of gone with the '96 I don't think I would have needed to do any further mods from the '91 non-ABS system. In other words, if you bolt in the '96 pedals I would expect the install to be as near "bolt in" as any other Jeep mod (you will still have to redo some brake lines at the prop valve and MC).
If I were you, I would pull the pedal assembly out of the donor vehicle (or out of a XJ of the same model year at least). The ABS system uses a return spring and the actuator pin on the pedal is in a different place than non-ABS assemblies. It is not difficult to swap the assemblies. IIRC there is only two more bolts on the assembly for its removal once the booster is removed.

As for the diff between the '88 and '90, I don't know what you mean. Differences in ABS systems, non-ABS systems, pedal assemblies?

I actually don't think there is any diff in the ABS stuff until DC finally ditched the Bendix system after '91. The non-abs stuff probably didn't change much through '96 with the dual diaphragm booster and I wouldn't expect much diff in the non-ABS pedal assemblies from '88 to '96 but as I don't have first had knowledge of this I won't guarantee there wasn't. I do know there were major changes in the new body style and that there isn't any feasible way to run a '99 pedal assembly in a '96 or older XJ.

Bones :skull1:
#6

 

[Christopher]

What was your solution for brake lights. I got the swap done and the brakes work great but the brake light switch from my '90 ABS wont work with the new assembly and the plug and wires on the '96 switch are totally different. What was your fix??

 

[Bones]

I honestly do not remember. Must be the CRS Dz kicking up.

I will look and get back with you.

IIRC it has something to do with zip ties, but I'm just not sure. :doh:

Bones :skull1:
#6

 

[Christopher]

Bones, have you had a chance to check on that brake light fix yet to see how you went about that. I've looked at it and still haven't come up with a solution. Thx.

 

[Bones]

Have I had a chance? Yes
Have I remembered to do it? No:looser:

I'll leave myself a note. PM me daily until I get you the info.
Man this CRS Dz is getting bad.

Bones :skull1:

 

[Christopher]

Hey bones?

 

[Bones]

Well I looked under the dash. What I found looked stock. Then I thought well sh*t :doh: . I used a '99 brake set up on my last swap so I had to use the pedal assembly from a non-ABS '91 I had already installed so things hooked right back up. What I do not remember is if I used the switch from the ABS set up or non-ABS set up.
Are you able to get pics of what you are up against? I can try to get pics of what I have and how the non-ABS set up is. I need to pull the ABS pedals out of storage and see how that set up compares.

The '91 switch is a press in self-adjusting set up. What is the '96 switch configured like (how does it compare with the earlier version)?

Are the plugs different between the two? How about wire counts between the two plugs?

Bones :skull1:

 

[Christopher]

Well here's what I've got. My '90 ABS had two switches. One was a screw in adjusting plastic with a vaccume hose connection (cruise control maybe??) and a two wire plug connection (torque converter lockup) which mouted to the assembly bracket and the pedal pressed the switch when brake was released. The other is a metal rocker switch that atached to the pedal where at the same spot the pedal attaches to the booster rod with two two wire plugs. It is this metal switch that controls the brake lights and that I can't mount on the '96 pedal. The '96 pedal assembly did not have this switch. What it had was a singal plastic switch above that had like 8 or so wires (none of the color coding matching what I have under my dash) with a single plug connection. Don't go diggin stuff out of of the garage to look. I'll figure somthing out. I was just hoping there might be a simple solution off the top of your head. Thank you.

 

[Bones]

No, my garage stuff won't help anyway. Sounds like the pre-'91 stuff is way different than the '91. I didn't have near that much stuff. Just a single plug. I'll have to take a look at an older XJ if I can find one and help come up with something.

Bones :skull1: