Oh, let me jump in on this one, and I am going to try to bleed things first, and the move from there on to the ABS craziness. This 92 XJS is worth saving, but not with new Teves 3 parts. I will look for the obvious first, then make sure the motor on the pump runs by testing the circuitry to it and a relay? How about a hard wire and a fuse if the electrics are fried? I had already purchased a ‘black ball’, so now I have two good ones! Oh, just wait until it warms up…
Ronald, you and I are on the same page. It was actually a pleasure to bleed the rear brakes today, since I have never done an ABS car before (XJS rear is active, front is passive and active). Pump the brake 20 times, connect a hose with bottle to the bleed nipple, loosen the bleed valve, turn the ignition and watch the pump push the fluid through. Super simple, super fast. What I found interesting is that even though I sucked as much brake fluid out the master reservoir as possible and filled with clean fluid, after bleeding front and back, as well as test drive, the fluid in the reservoir is quite murky again. I guess it’s flow back from the ABS system and dregs in the reservoir.
Paul,
My failure occurred 3 different times. The first time was when I pulled into a gas station after an interstate drive. I flew right by the gas pumps and out the other side. Lucky, no cars in the way. This will make a believer of anyone. Kirby is correct that changing the teaves out will solve all problems. In my case, no money, no time to do it and no experience in finding the parts and doing the change. I am an electronics guy. In the beginning, it was suggested on this site that I could remove the fuse and blue switch connectors and it would limit the car to front brakes and remove the ABS. I drove the car for a year or so and then one day the foot went to the floor and I almost flew through a 4 lane major intersection….down shifted, pulled the hand brake and I believe cut the engine in less than 5 seconds. You need to practice this for when you have a Marelli failure. Practice helps. This was unexpected as this was not supposed to happen when using the front brakes only. Well, it did. So I was moved to wash out the whole system. I did not expect this to help, but a pretty simple job. Again, you have to clean every single part in the system. Remove the master cylinder and push the pistons with a wooden rod. You have to clean everything. Buick and Pontiac used a similar system for several years without problems. It was the Jag engineers that failed to understand the possibility of total failure. In the States, it is required that the front and back brakes are on separate systems. The US inspectors also failed to detect the problem. I have had no problems since and I have great brakes. But, be aware: I fully expect to have the peddle go to the floor again someday. Harry…90 XJ-S drop head and 48 3.5 Saloon.
Yes, that is what happens, and purchased here, brake fluid is cheap. I would drive the car while it’s murky and wait until you are ready to do it again, if the brakes are working fine. Remember, you are actually cleaning out the system, and some gunk will come loose in the process. This means all the stuff in the calipers will get a clean-up too, so they might spring leaks. Keep looking and watching. I once dropped the rear on a Jag and fixed the one caliper that was leaking (big mistake) and put it all back up in the car. Next day, the other side was leaking. Eight hours shot to hell. Thanks for the heads up on the rear bleeding!
Paul, Sorry, I forgot to say, yes, the brakes recovered after pumping the peddle as fast as I could…but it would fail again a few miles later on the way home. Also, my car is not a daily driver……sunny days, and weekend jaunts or on a special day to work. Harry
Paul,
As Ronald said, there is all kinds of gunk coating the sides and walls of every pipe, tube etc in the brake system. You must use a solvent to clean everything… Running clean brake fluid through the system is not the answer. I probably ran 10 or 12 cans of brake cleaner and 2 or 3 gallons of brake fluid before I felt confident things were reasonably clean. You can test tubes etc. with pipe cleaners and small round brushes. Then rinse again to remove the crud you have just disturbed.I know that it is not perfect. It is like cholesterol in your blood system. It is going to cut loose some day. The brake fluid is murky because it has watered brake fluid and oxidation. Think about the corrosion on any aluminum part…look at things under your bonnet…the calipers are full of this gunk. Everyone should have their brake system drained every few years as it will collect moisture. Harry
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Bad suggestion! There’s reportedly a way to cut power to the ABS computer but leave the power connected to the pump, which will give you brakes on all four wheels working as they should, but no ABS function. Trouble is, if there’s a blown hose to a front brake caliper you still have no brakes.
Who told you that?
Well, to be fair, the front and back are two separate circuits. The US inspectors failed to notice that when the front circuit fails, it prevents operation of the rear.
For those of you who are unwilling to drive a dangerous car: The solution is to toss the Teves III over the hedge and retrofit a pre-ABS vacuum boosted power brake system. Easy and cheap.
Do you have steps on how to do the transplant, what specific parts I need to buy and whether I buy new, or used?
The hard part is finding a pedal box and pedals from a pre-1988 XJ-S. The pedal box from a Jaguar saloon won’t do, it must be from an XJ-S. And I doubt if new exists, but should be pretty easy to find from a junkyard or somebody’s parts car.
You’ll also need a master cylinder – buy new or freshly rebuilt. And a vacuum servo – buy new. And a brake fluid reservoir – buy new from Mitsubishi and fab a bracket to mount. You’ll need some hose that’s compatible with brake fluid (NOT fuel hose!) in two sizes and a pair of adapters to connect the reservoir to the master cylinder. The final thing you’ll need is to connect the brake lines to the master cylinder, which may involve bending some brake lines.
All of which is easier and cheaper than trying to get the Teves III valve body/master cylinder to work after it has malfunctioned. And you never have to worry about total loss of brakes again.
Doesn’t sound easy for a non-mechanic. I honestly like this option, but am worried that I get started and find I have bitten off more than I can chew mid-way though. I am a technical/mechanics guy by nature, but you get the brakes wrong, could be the last job you do. Am torn here.
I hate the over assisted brakes on modern cars. Best brake pedal feel I’ve had was from an unassisted set up, with a track day E type and my own Alfa Spider. It will seem rock hard at first, but great feel when you get used to it. My XJR-S’s ABS system seems a bit mushy, but a fully manual system may be a bit much for such a heavy car.
In any case, big changes in safety systems may not be looked upon favourably depending on your location. The UK MOT is getting stricter on what is allowed as a modification - I had to justify the deletion of the rear anti-roll bar after upgrading my suspension.
i kinda agree. Search the archives, I swear about 6 months ago someone did exactly all of this, with some great write-ups. But it seemed to be a much bigger job than simply retrofitting an older system.
Well, the guy that did it a few months ago decided not to find a pre-ABS pedal housing but rather to fab an adapter for the ABS pedal housing, which was quite involved. Then the OEM vacuum boost module wouldn’t fit, so he had to find a smaller vacuum boost module that would fit with the pedal housing he had cobbled. I have no idea why he was so determined to do things the hard way. Find a pre-ABS pedal housing and pedals. Everything else falls into place after that.
i am game to try anything, but being unfamiliar with these brake systems (i can tear a motorcycle brake system down and rebuild in my sleep, but not car), was looking for something a little more formal, such as a list of part numbers for major components etc. if it was just as simple as ‘strip the following components off a pre-88 donor XJ-S’, that would work, but from your prior post, that doesn’t seem to be what you are suggesting, which is a mix of old and new parts, jag and non-jag. I have searched the archives and see a lot of ‘high level’ discussions, but no in-depth tutorials. Would such a thing exist, just to make sure i don’t screw this up?
But it is what I am suggesting. You need the pedal box and brake pedal.
Ok, I will try to find the pedal box and pedal and take it from there. Hope you don’t mind me dogging you with additional questions during the process, since you are a life saver.
You can pick up the master cylinder, vacuum boost module, and fluid reservoir from the same source while you’re at it, but I’d recommend you buy those parts new or rebuilt. Having old ones might save you a core charge. At least you’d see how they go together.
Thanks. Do you have a source for such parts, outside of ebay? i have been looking for local (Tulsa) merchants that deal in used/reconditioned parts and cant find any that deal with Jaguar.
i bought a remanufactured master cylinder for only about $140. BUT, the issue I ran into, they do not come with the little white things in this picture, and they sent me the wrong seals for those white things.
I believe the seals you can find (getting the white things plugged in is a bugger!)
But the white things are very difficult to find. Mine were hard and brittle, so I managed to find some New Old Stock out there. You may too, or get some used ones in decent condition.
There may be some VW parts that fit, but I didn’t research that.
Here is a photo of the Centric rebuilt I got. No white things. And as you can see, left seal looks way too small.
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This seems to indicate I can buy a new one for $150, which is amazing!