I received my touch-up paint today for the area under the mc. I'll be putting the system back in the car this weekend. Wish me luck!

 

Good luck!

 

Hi David

Genius! I wouldn't know where to start with this, so hope you will still go ahead with your Step by Step instruction guide.

I actually had a bit of luck, as my 1988 XJS hard top scrapper has got the complete system in, so I could take it out and test it, then put it in the Car that has the problem, if only I knew how!

I was going to take the unit out of my scrapper but I'm not sure what to do or where to start.

I could take the whole thing out including the pedal box or just disconnect it from this but my big problem is in knowing how to get the spanners on it, as the plastic reservoir on the top is right in the way.

And I cannot see the way to take it off, if I need to?

 

Hi Orange,


If I assume your 88 setup is the same as my 90, there is a small metal clip with an allen nut that is under the reservoir near the front that holds the entire thing onto the master cylinder assembly. On mine, if I tip my head upside down, looking under the reservoir towards the drivers seat, I can see it. I unscrewed that and then rocked back and forth until the reservoir came off. There are two grommets between the mc and the reservoir that also hold it fairly tight, that's why I rocked it around while pulling it to take it off. Make sure the brake fluid is out first so you don't get it all over the paint in the engine compartment (why I'm repainting some of that area).


To disconnect the mc, FIRST, disconnect the 4 hard brake lines and cap them. 3 go to that crappy abs solenoid, the 4th goes to the mc. Then, you will have to remove the pedal box from the firewall. 4 nuts hold it on. Inside however, there is a cotter pin holding the assembly to the brake pedal. I couldn't fit my hand in there from the engine compartment, so I went in from the drivers foot well (yes, legs up in the air, head by the pedals).


So, remove the reservoir, remove the 4 nuts holding the pedal box to the firewall, remove the cotter pin and post from the inside to remove the pedal, the entire thing comes out. Really, not too bad.


The Jaguar repair manual was pretty good explaining these steps. If you don't have that, buy it and buy it on dvd so you can search it more easily. I only have the book, which is still invaluable.


I can scan the pages and take some pics this weekend if that helps.


Sounds like your issue is the same as mine. If that is the case, you could just replace the abs valve block. That is pretty simple. Whatever you do, when you remove an abs valve block make sure you find and save the square edge washers that go between the valve block and the mc. Those are IMPOSSIBLE to buy new.
I'm attaching a document that illustrates this shorter process recommended by a tech bulletin from Jaguar. You can actually buy these kits new still. I saw one on Ebay for $400.


Let me know if I can help with anything. Yes, I am going to post my entire process in a pdf document that anyone should be able to follow.

 

Hi David

I was so preoccupied in taking the Radiator out of my 88 scrapper, that the fact I had a complete ABS, just went right over my head and what I was desperately trying to find was under my nose all the time!

Visually it looks the same as on my 1990 which has the braking problem but getting that thing out of the Car, seemed like trying to do a Rubic Cube with a blindfold on!

As although I could see all the bolts, I couldn't see how to undo them or how to get that plastic reservoir off, as with that in the way its tantamount to impossible!

So the first thing that I 'think' I need do, is check the electric solenoids on the Valves, which I don't know how to do and what you recommended to do first, so help on that would be appreciated.

If the electric side is OK, then it would probably make good sense to just change the valve block on the ABS so as to disturb the original set up on my 1990 as little as possible.

Assuming the electric side of the ABS checks out, if it were you would you just swop the Valve block, which I am assuming is the long tube with the brake fluid outlets on, or would you recondition it in some way?

Please excuse my ignorance here but I'm not even sure what the valve block bit looks like, which 'is rocket science' as far as I am concerned!
So any photo's and guidance would be appreciated.

When I take it out of the scrapper I will just cut through the pipes, to seal the tubes and prevent any dirt getting in.

Also I'm really going to try and put some photos up as I now have an account with Photobucket so you and others will be able to see what I'm either doing right or wrong.

If you could assist me in how to include the URL of the photo in a post that would be great. (anyone else is welcome to chip in)

No one on the Planet that I have been able to find, seems to know how to do what you are doing! Google XJS pulls to the right and you just get a blank.

A mate of mine sold a nice XJS because of this very problem, which no one knew how to fix.

 

Good Luck to You and me both!

 

Hi Orange,

I'd recommend just swapping the valve block. You don't have to take anything else off of the assembly. The block is pictured in the images in my posting. It has three (3) hard brake lines running to it, a 7 pin electrical connector, and sits facing the left side of the engine (assuming you have a LHD car). You can electrically test the unit, but if you only have a sticky solenoid like mine, you will measure all correct. It is easy and should be done, including the connector of the main valve on the master cylinder.
I'm attaching an image of the unit (out of my car) and labeling Pin 1 and Pin 7. Pin 7 is Ground. The other 6 pins will measure the 3 inlet valves and 3 outlet valves.
Inlet valves will measure 5-7 ohms, outlet valves will measure 3-5 ohms. Put one probe on Pin 7 for ground and just put the other probe on each pin and look at the reading.
For the Main Valve, disconnect the two pin connector at the end of the master cylinder (towards the front of the car) and put your leads, one on each pin and see what you get. You should get 2-5 ohms.



This is the simplest way to measure. Again, if you have a sticky valve solenoid, you may measure all good and it still is not functioning.
Use the pdf I uploaded in my previous post for detailed instructions and images to swap out your valve block.
PAY ATTENTION to the 4 rubber (EPDM material) square edge O-rings that go between your valve block and your master cylinder. SAVE those and reuse. Do NOT use a replacement unless it is exactly to spec and made of EPDM, not rubber. Rubber or something made for other materials than brake fluid will fail.
The pdf in the previous post shows the exact location of where you will find those. If you just leave the MC in your car and swap the block, be very careful not to lose those washers....they may fall off when you remove the unit or stick to the mc side.
Make sure to empty all fluid from the reservoir before starting and when you undo the three hard brake hoses, take care of dripping fluid. Sucks to get it on the paint.

I hope this helps. That should be about a 2 hour job. You will then have to bleed the system. Take care to note the bleed instructions in the repair manual. You can f up the abs block if you force fluid back into the block.
Really, should be pretty simple. Use a power bleeder, the rear brakes bleed themselves using the abs pump. You will still need a partner.
Good luck! If this is too much, I'd strongly recommend having someone who is familiar with this help you out.
My Best!

 

Hi David

Somehow I completely missed the link to the PDF!

Though now that I've found it all I can say is 'Brilliant Job Well Done'

Although you may not have realized, you went and hit the nail right on the head!

When you say you can 'F' the Abs Block, by forcing fluid up it the wrong way. As that is exactly what I must have done!

So the problem is almost Certainly not Electrical.

Everything was working fine until I put new 'Pads' in, which involved me pushing the Caliper Pistons back!

On any other Car it wouldn't matter but with the benefit of hindsight, it certainly does on a Jaguar XJS where doing so 'F' the Block on the ABS.

So unless you need to add anything, that is what I'm planning to do, though cannot believe you can do it in only 2 hours!

That would be amazing! as my friend just gave up and sold a very nice XJS with this problem for Scrap money!

Right now I am preoccupied in getting my other XJS through the MOT which had been off the Road since 2005! where the engine hadn't been started or even turned over during that time!

I recently put a battery on, turned the key and She started first time!, just as if I'd been using her every day.

So once I get her MOT'd I will then sort out the problem with the ABS on the other one.

Which I must add I could never have done without your Invaluable help.

I've now learned how to put Pic's up, so when I start to take the valve block off, I will take some pics, so you can keep an eye on what I'm doing, which could also be used to help somebody else.

Thank you very much

You are a 'Trooper!'

 

I'm really glad that my work might have helped you. I spent so many hours researching this issue, I thought if I had found a topic posted like this it would have saved me a LOT of time (and some people from ditching their XJ-S). That's why I'm putting together a document to summarize all of this. Seems many people have this issue with the Teves Mark II system. That system was used by many auto manufacturers, not just Jaguar. I found quite a few technical bulletins by other auto manufacturers describing the same issue and the same instructions to fix it.
Granted, there are other possibilities of why this happens, but the most common reason is the abs valve block.
Personally, I think abs is really for people who don't know or want to learn how to emergency brake. It removes the driver, yet again, one more step away from the actual wheels hitting the road.
I thought of removing the abs system, but with my desire to keep the XJ-S somewhat original, it felt like cheating!
Keep fighting the good fight!

 

Hi David

There is nothing out there, like what you have come up with, one guy told me to get some speed and then Stamp Hard on the Brakes.

But in the event I had done what he said, I think it would have put the Steering out or even worse.

I've just got to get my present Car through the MOT and then I can start sorting out the ABS on the other one.

Thanks for your on going help, which is very much appreciated.

 

I did what that guy suggested. I was only on my neighborhood streets and was going about 10 mph when I tried to engage the abs. It did completely jam that valve open and I had absolutely no braking on the right front side. The next day I tried driving it and it had subsided a little. There are three positions those valves can operate in. I also did it with the ignition off, coasting about 7 mph and braking. Same issue that confirmed it was not electrical. I've heard that braking like that sometimes loosens the valve and if there is a little piece of gunk in it, it may brake loose. That wasn't the case for mine, or probably yours. The old valves sometimes stick, or if you forced fluid back into the block when compressing your calipers when you replaced your pads, that can actually damage the inside of the valve. At some point, that may have happened with this car when the pads were being changed.


I'm attaching a pretty good document (for when you are so bored you are ready to jam a pencil in your neck) about the Teves Mark II abs system. Make sure you read this at work. Real men get paid to figure out their Jaguar issues.

 

Hi David

OMG! Just had a quick look at that PDF which really got me wondering, if they could possibly try and make that system even more Complicated!

There are so many things to go wrong with this, that its making my Head Spin! No wonder they want so much money for a replacement!

Already my old 'Scrapper' is looking like its worth its weight in gold, there are lots of bits and pieces on it, that would cost a fortune to buy, even if you knew where you could find them.

So the 'Stamping' on the brakes idea, wasn't quite so 'bonkers' after all! but even so I thought it was nothing short of very 'wishful thinking' that something like that might work.

If I knew what I was doing like you! I would be very tempted to go back to non ABS, as with most other things in life, they probably went and got it right the first time!

Many so called 'improvements!' only serve to go and 'Screw things up!'

A little bit like the Exhaust on '50 Shades' my Grey V12 XJS Which I named after a book I've never read! (being 50 shades of grey)

Which is pretty much 'Chick' related so I'm told.

I am totally baffled as to why they looped that Exhaust pipe over the cage, when a dead straight pipe would probably do the job better!

When it finally gives up the 'ghost' if I don't do that first, I think I will get a Custom one made up, and preferably one made out of Stainless Steel!

 

While installing the master cylinder to the brake pedal last night I broke my damn brake light switch. Cheap plastic thing snapped while my head was upside down in the foot well. Little pieces landed on my face. Words came out of my mouth. I have a new one coming this weekend. $45. THEN, I'll finish the job.

 

OMG! David $45 what a total rip off!

Talking of which I 'nearly paid' £15! for 8 Anti Roll Bar Rubbers!

Then I found some on ebay! Brand New £5 including free delivery!

 

I finished the job today and it all works! Problem solved. I'll put everything together in a document and post it here for anyone interested. Thanks for following my posting and the great support, especially 'Orange Blossom'.

One point to follow up on from my last post about the brake light switch I busted. When doing this job, get your head in the footwell and remove the 4 screws that hole the plate that holds the brake light switch and remove that before doing anything. Remove the entire ABS assembly along with the pedal right out of the engine compartment. Remove the pedal on your bench, then do the work. Install the brake light switch last after everything else is in. This will most likely save you from breaking yours like I did mine.

In the document, I'll include a quick and easy way to do this job and a more thorough method I used, including brake hoses, pads, bleeding, valve block, etc.

 

Hi David

Congratulations on fixing the ABS on your XJS which is a massive achievement in every sense of the word.

When you said that I might only have to change the 'Valve Block' would you suggest I remove the whole thing which would include the 'Pedal Box' or just unbolt the 'Valve Block' and leave the rest in the Car?

Also are there any new parts that I would have buy or replace before putting it all back together?

Many Thanks for your help

What you have managed to do on your own, is nothing short of ingenious!

So Well Done!

 

Hi Orange,

You will have to bleed the entire system, so I'd say just take the whole unit out of the car, put it on a bench and do the job. Take the reservoir off before removing the entire assembly, careful to drain the fluid. Paint doesn't like it. Just note, make sure you get your head looking up where your brake pedal goes in the footwell. remove the four screws that hold the plate on that holds the brake light switch and take that switch out attached to that plate BEFORE you do anything and install that last. I'm attaching a pic of that thing. You may have an issue removing that switch as I did. The wires, for some reason, are tucked above the steering column, making it very hard to remove. You might open the cheek that covers the main fuse box above the driver's knees and see it from there. If you leave it in, be very careful with the brake pedal as not to brake that plastic switch. The brake pedal rests on it to activate the brake lights when depressed.

Once on the bench, you can remove the valve block when it is facing up. Make sure you keep careful track of those 4 square edge o-rings that go between the valve block and the master cylinder. Use that pdf I posted that shows how to replace the valve block.

I guess both methods are a pain in the A, you could just remove the valve block and leave the rest in. Just be careful to install the square edge o-rings properly if you leave the assembly in the car. They should stick pretty well with some brake fluid on them.

Good luck!!

 

Hi David

Paintwork won't be an issue with my 'Scrapper' as it is a total basket case.

So unless you can think of any good reason not to.

The first thing I am planning to do, is to remove the plastic reservoir so that I can 'hopefully' get to the bolts to unbolt the 'Valve Block'

Then undo the 'Bleed Screws' on the Calipers, on my 'Good Car' and using the pedal, pump all the brake fluid out.

Then spray 'Spray Grease' all around the system on my 'Good Car' to help protect the 'Paint Work' in the engine compartment.

Backed up by lots of pieces of rag to mop up any spills.

Then making sure that I don't lose the square 'O' rings, remove the faulty 'Valve Block' from my 'Good Car' and then bolt on the other one from my 'Scrapper'

Reconnect the brake pipes and then refill the system with dot4 Brake Fluid. Which I seemed to remember you said you used?

Then get a mate of mine to help me bleed the brakes.

After which I hope it will work as well as it did before I messed it up!

Just wondering if it is possible, or if you have tried to recondition the 'Valve Block' as it would be handy to have one as a spare, as from what I can tell, they are like finding 'Gold Dust'

Going off on a Tangent, they say that prevention is much better than cure and so to begin with, I'll hold up my hands and say 'I messed it up!' and all because I didn't know how to replace the 'brake pads' on an XJS.

I did this exactly the same way that I've done with every car I've ever owned.

Which often involves levering back the pistons in the Calipers, so that you can get enough space to put the new pads in.

Its never been a problem on any other Car but doing it on an XJS must have forced some fluid back into the 'Valve Block' which then messed everything up.

Knowing that now, I don't want to do that again! and certainly would not trust a garage (outside of a Main Dealership) to do it.

So if you get stuck for a 'Project' how about a 'PDF' of the correct way to do it, as I for one would really find that useful.

I cannot express my Thanks enough for what you have achieved and then passed on to people like myself, who simply didn't have a clue as to how to do what you have done.

 

Hi Orange,
Sounds pretty good to me.

1. Disconnect the negative battery cable.
2. Detach the electrical connectors from the reservoir cap. Unlock and remove the cap.
3. Empty the reservoir of as much fluid as possible using a clean large rubber syringe or suction gun.
4. Remove the line between the pump and reservoir by twisting and pulling the hose from the reservoir fitting.
5. Remove the return line between the reservoir and master cylinder at the reservoir in the same manner as Step 4.
6. Remove the 4mm allen head reservoir mounting screw.
7. Pry the reservoir from the booster housing carefully. Be sure the short sleeve and O-ring are removed from the booster housing.
8. Install the reservoir mounting bracket in its guide on the bottom of the reservoir. Check to be sure that the short sleeve and O-ring are in position at the bottom of the reservoir. Wet the mounting grommet with brake fluid.
9. Insert the reservoir into the grommets on the booster housing, as far as it will go. Make sure the short sleeve and O-ring are in place. The reservoir should be held vertically during installation.
10. The rest of the installation is in the reverse order of removal.
11. Fill the reservoir to the correct level with a charged accumulator. Bleed the system.

I did not open my bleed screws at the calipers when I did this. After draining the fluid from the reservoir, I just unscrewed the three brake lines from the valve block and the other one that goes to the vacuum pump with a rag under the openings. Not much fluid came out.
The image here is not exact of your system, but it shows the tiny plastic sleeve and O-ring that go with the reservoir into the master cylinder.
Let me know if you need anything and I'll be happy to help.
P.S. working on the document for this entire job....

 

Hi David

So glad you put that diagram up, as after removing the allen screw, I would have been scratching my head as to what to do next!

Before you put this post up, I was asking everyone about this braking problem, including a 'so called' 'Jaguar Expert' who didn't know what to do, apart from suggesting I bought a brand new unit.

As I'm sure I've mentioned before, I was quoted £1,000! which seems to be a crazy amount of money for something like that.

So I just can't wait to get started on this, as soon as I have the XJS that I have just got out of a long lay up hopefully through the UK MOT.

Then without any distractions, I can finally get stuck in!

Thank you so much for your help, which is appreciated very much.