Brake swap

i was wondering if the wheel cylinders, calipers, and proportioning valve from an ABS system are the same as a non abs system. I have a 90 limited with abs with no power assist and a continously running pump and plan to convert it to a non abs system.

i believe the pump is lifetime warranty, usually the accumulator fails and wont allow the system to come up to pressure. when the pump runs continuously, is burns out. i think the accumulator is about $100. that and a free pump may be less expensive than replacing everything to convert it over.

the reason I plan on doing this swap is that i plan to run 30x950x15's and do not want to have problems with the abs not functioning properly. also I can get a a booster and master cylinder (master cylinder looks new)for $25 at a local garage.

if you fix the abs correctly, you have the same chances of brake failure as conventional brakes. new abs components are far better than "new looking" parts.

Bones has a write-up on swapping out that old style deathn trap of an ABS system. This is one where I disagree with jneary. Get rid of that ABS ASAP.

the only major fault in my opinion is the accumulator for the abs. when that fails it can cause the pump to burn out from continuously running. like i said for about $100 you can have a new accumulator, and if the pump is bad it should be covered under the lifetime warranty. in my 17 years of working on jeeps at a jeep dealership i have installed more hydraulic brake components on all models than bendix abs components. once repaired correctly we never see them back for the same thing. its your time and money you can choose to do wiith it what you want, but i am trying to save you the trouble.

I hear ya ... but -

1. The Bendix ABS was such a defective design that the Federal gummint forced DaimlerChrysler to warrant certain parts of it FOR LIFE. That's almost unheard of and to me indicates a serious flaw designed into the system.

2. When an ABS system fails, it is supposed to default to conventional braking. It's my undertanding that the Bendix system can fail (and has failed) leaving NO brakes.

I'd rather not take that chance. A conventional brake system is designed so you at least have brakes on two wheels if there's a problem. I can drive a vehicle with 2-wheel brakes. I don't want to try it with no-wheel brakes.

Thanks for the info. I plan on swaping the brakes over the next two weeks to the conventional system.

I don't mean to hi-jack here but what year did they start putting ABS in the XJ?

Marty

'91 XJ 4x4, 2 dr, 5-spd 223,500 km and counting. And a Punisher sticker!

cdnxj said:

I don't mean to hi-jack here but what year did they start putting ABS in the XJ?

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1989

Eagle said:

1989

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Thanks! Eagle you seem to be the resident expert. Should have asked this before but did they all come with ABS? Was it an option? And what would I look for if I had it. I'm doing my brakes next weekend, so I'll need when I buy parts. Thanks again!

Marty

'91 XJ 4x4, 2 dr, 5-spd 223,500 km and counting. And a Punisher sticker!

Just an added opinion on these abs systems. They are warranted for life, as the 3 pumps and one accumulator on my 91 can attest to, but there is a high pressure line that runs accross the firewall from the pump to the accumulator. I've had that rupture on mine, luckily while it was still parked in the garage. I'd hate to see what would happen if that had happened in tight traffic or towin my boat!! Anyway, just my two cents.

I noticed today that the header panel has been changed on my 90 limited. Curently brakes are not getting any boost. Master cylinder and pump appear to have been changed ,most likely for being defective. Coincidence? I don't want to find out . I'm going to convert the system and probably use dot 5 silicone fluid

cdnxj said:

... did they all come with ABS? Was it an option? And what would I look for if I had it.

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They did not all have it. It was always an option, right through the end in 2001. Don't know what to look for in your year, I've never worked on one that had it.

Mountain Man said:

I'm going to convert the system and probably use dot 5 silicone fluid

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Despite recent comments that the stuff is no good (with no reason given that I can recall), I've been running DOT 5 silicone in the brakes of my '88 XJ for more than 10 years and will continue to do so. Since I replaced the clutch in 2001 I've also been using it in the clutch hydraulics. "They" told me it wouldn't work there, either.

Mountain Man,

Be sure the fluid you are going to will be compatible with your system. I recall years back being stranded and filling the clutch resevoir on my old toyota with hydraulic fluic as it had leaked and ran dry. It worked for a couple days but apparantly the silicone in the hydrualic oil does something to the seals used for plain old brake fluid and caused them to rupture requiring a new slave, and master.

I had my ABS fixed it only cost $450. The pump is on a recall, so it gets replaced for free. The accumulator almost always leaks, which causes your motor to constantly run, then burn out.

Don't mean to hi-jack the thread, but I'm in the same boat. My '91 system is shot too. The previous owner told me it was the brake booster - I didn't know at the time it was an ABS system or anything about it being prone to failure. So, I too am considering switching to convential brakes.

My ABS & Brake lights are constantly on. I hear no pump turn on/off. I found a wiring harness disconnected in the area of the booster though, but never plugged it in to see what would happen. This is the first that I'm hearing of the accumulator going bad - could this harness just be the power for the pump? Maybe the previous owner disconnected so that he didn't have to hear it constantly run? Here's pics:





What do you think? If it's only an accum., I will just try that. Why would the ABS light be on though? I do have some brakes right now, but it's two feet on the pedal and don't follow too closely if you know what I mean. I only drive it about 10 miles a month at the moment, so it's not a big deal. I do have a lift ready for it and am planning on 31 or 33" muds, so I'm skeptical about this system.

If I do decide to switch to conventional, I want to get 95-96 booster/master cylinder and the same year pedal setup. Does anyone know what adapters (the exact sizes or part # from say NAPA, Discount auto or Autozone) to get to use my current lines w/ new booster? Anything else I'd need for the swap? I can use the same proportioning valve right? Where does the vacuum line connect and is my vehicle equipped and just plugged or is there another part I need (besides the hose)?

Thanks for any help.

bump for any help...

nothing?