Had the "cat" out yesterday and she was doing just fine (1993 XJS Convertible, 4.0L, automatic). Hit the brakes and she felt odd, kept going and hit the brake at the next stop and she pulled a little to the right and the ABS system kicked in. At the next stop she pulled harder to the right and when I began to accelerate the right front brake was hanging up. I pulled into a parking lot, put it in park, and smoke started coming out from the right front brake (seized caliper). Before I shut the engine off I noticed the ABS light was on. After the smoke went away I tried to move the Jag and no problem although the ABS light stayed on. As I was backing up I hit the brakes and...nothing! No brakes of any kind. I checked the fluid and there is plenty but I have no brakes and the ABS light stays on. I know regular brakes like on my 87 Hess & Eisenhardt but my 93 with the ABS has me in need of assistance. Help!

 

Sorry to hear about your problem. Glad the "total failure" mode happened when you where backing up and under control.

Every once in a while I hear of this type of total failure on the ABS XJS' and it really makes me very nervous. I imagine you had no warning light on before this happened?

Hopefully it's not the actuator or accumulator pump. Based on your caliper being stuck I imagine it could be a hose self destructing internally? Don't know..

 

ABS light on but red brake light not on means no ABS. Usually sensor, sensor wiring, accumulator or valve body. Based on the symptoms I'd say valve body aka master cylinder. Or the pump has packed in but again not consistent with symptoms. Check pressure at each caliper with ignition on. The unit is expensive but can be rebuilt or you can get a use d one from a breaker. If you search for threads I hve posted to you will find two or three where there is more info, including tips on other cars using the same system (Teeves or ATE for Alfred Teeves). The Buick has a forum where more info can be harvested.

 

The ABS light was on, the brake light was on and the safety brake light was on all at the same time. After I let the car sit for about 15 minutes the frozen caliper became unfrozen. My thought is the ABS was feeding brake fluid to the caliper but not the other calipers and the one getting all the pressure froze. The brake pads were smoking on the right side front. After the smoke died down the lights were still on and no brakes. There was no pressure at all and the pedal went straight to the floor. I looked for fluid leakage but everything was fine.

 

Glad you're okay. How did you actually stop the car when you were backing up? Parking brake?

 

When was the last time you changed the brake fluid? You may have boiled the fluid, that would take out the brakes. Make sure you have dot 4 fluid in there.

Cheers,

Allan

 

Just a caveat: When replacing pads open the bleed screws to avoid pushing contaminated fluid back into the mc. And if air in system follow bleeding procedure incl pump bleeding if level went too low. And +1 on the boiled fluid so bleed with full flow of new fluid. Since the brake fail light was on as well it could be internally collapsed flex hose as noted above. There is a fault code system for the ABS, refer to the previously mentioned threads.

 

Fastcat: I was only doing about 5 or 6 miles an hour, perhaps less. I was heading toward a tree so, with no other options I had to put it in park. She ground just a little and stopped without any big jerking. I know you do not do this as a habit but if there is no other recourse...

 

Allen and Per: I just bought the cat on monday. I do not think the fluid has ever been changed. It did have an odd smell so I will bleed the whole system and replace the flex brake lines...just in case. Thanks very much because I was getting data on a tear-down of the ABS system.

 

Did you try the park brake instead of just putting it in park?
Cheers, RagJag

 

Well, ya gotta do what ya gotta do. Sticking it in park is usually better than hitting a tree!!

It's odd to have a failure like that effect both the front and rear brake circuit at the same time. It makes me think that maybe the rears might have been malfunctioning before you experienced the problem with the fronts. Or then again, maybe it's got something to do with the ABS module. Wish I could be more help!

 

Rag-Jag: I grabbed the safety first and pulled as hard as I could with no results except getting the safety light on the dash. There are no brake primary or secondary. That is why I said YIKES! Thanks.

 

FastKat: I think you are correct as there may have been a safety light lit up on the dash. I think from the lack of reaction by the safety brake that it may be seized and cannot function. Busted cable maybe? Once I get the car up off the ground using a 15 ton floor jack we use once in a while for bus repairs, I will have a better idea, but I am figuring rebuilding the safety system. This was the first time I ever had a need to use the safety.

 

I'd love to know what happened here, once you get it corrected. Something keeps telling me this is a master cylinder problem, not ABS...I almost wanna take a look at the car myself.

 

Mkii250: Since I will be tearing into the brake system anyhow, I will do a rebuild on the master cylinder. Thanks for the idea.

 

Disc overheating is a piston failing to come off because it is stiff through lack of use.

I had brake failure this summer. Here is a link to a post I made regarding the ABS solenoids and resolving the issue with them.
Jaguar World Monthly Forum - Total Brake failure Teeves Mk II '89

Hope it helps

 

I wonder if anyone has eliminated the anti-lock brake system on these cars. The pre anti systems worked just fine and didn't have sudden catastrophic failures. I am not a fan of any device that can cause something like that.
RagJag

 

Schoe, I think you will find that the shoes are worn out on your emergency brake. They get left on quite often because the little dash light isn't easy to see and the lever is down.
Cheers, RagJag

 

I took the master cylinder out and cleaned it up. The "rubber" parts are in good condition. I am going to try what Somethingsomewhere tried with his Jag. I am now placing my problems on the ABS system and will go through the whole system. If worse comes to worse I will go to the local recyclers and find an old General Motors or Jeep product and get their master cylinder. I would just dump the ABS system and go with a pre-ABS brake system, but I have no idea what I would need. RagJag, you are correct on the shoes for the safety, I will have to replace them. I will let you all know how it goes.

 

Are there anyone out there that have eliminated the ABS on one of these cars? I may be wrong but it seems to me that brake lines could be installed from the master cylinder to the lines going to the wheel calipers directly thus completely removing the ABS failure problem. May not be legal but I can't see how it would be any more dangerous than the ABS failure.
Thoughts, ladies and gentlemen?
RagJag