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OB
What you have pioneered in explaining and fixing the Teves ABS system to everyone, is nothing short of a MAJOR contribution to keeping these cars on the road. All the ABS car'd people (thankfully I am pre-ABS) are in your debt. Nobody wanted to go near it until you got stuck in!
I hereby award you the GiF order of merit First Class. (I am sure that Grant will knock up a certificate for you!).
Brake block
But the actual actuators are pretty gummed up.
Brake actuator
So how do these actually work? There is a little click on most of them, but I don’t see anything move. It there valve movement internal to this actuator?
OB was right- the ribbon wiring is super fragile. Kind of like tissue paper. I can figure out the wiring to replace it, but since the actuators all have continuity, it is not super easy to isolate each wire with a continuity tester on the multimeter. I can probably re-wire it using thin copper telephone wire, but…
So I ordered an XJ6 valve block- the one with the slightly thinner plate. I’ll give that a shot, and put off messing with this one anymore.
Including how to remove the Speedo Binnacle on an XJS 4.0L if you are having problems with your Speedo (Similar procedure on all XJS Varients)
How the GF Fixed the Speedo on my 1990 XJS V12 (The whole embarrassing Saga of how the GF Fixed the Speedo on my 1990 XJS V12) although I'm finally over it now, although on Second Thoughts maybe I'm not
If you're thinking of Fitting a New Stereo to replace the Jaguar one, over the Bank Holiday here is how I did mine and though I had never done this before it is a whole lot easier than the Spaghetti Wiring makes it look Fitting a New Stereo in an XJS V12
Also Note the Fuse Holder hidden away out of sight in the empty cavity that the Stereo fits into, as one day you could be tearing your Hair out trying to find it! (ask me how I know or rather don't)
How do you know it was the teves? My front calipers have both seized I've checked the pump and it seems to be working and cuts off as required. No ABS lives showing on my dash. I'm starting to get desperate and need help.
If the calipers have seized, unless there is line pressure in the system, brakes off, then unbolt them and then fix or replace them. If you loosen off the brake flexible just enough for a dribble of fluid and the brakes does not free off, then this shows line pressure is not the problem.
Last edited by Greg in France; 05-01-2022 at 12:08 AM.
First off massive thank you to OB for putting this thread together to share the knowledge. As someone going through brake issues on an XJS it is a massive help.
Someone posted a link stating if the solenoid resistance is 6ohms it’s bad, but good if it’s 3? Has this been confirmed or is there rational for this? My solenoids all click when 12V applied and the ribbon cable is in great shape. So curious how a 3 ohm difference can differentiate good from bad.
The issue is 80% of the brake pedal travel performs no braking action. The last 20% starts applying brakes and considerable force is required to perform an emergency stop, or hold the car on an incline. The brake warning light comes on when the car is started and stays on for 40-50seconds before clicking off. I get about 1-3 quick peddle presses before the brake light illuminates again, and it stays on for 10-15 seconds. What is interesting is an audible hissing sound is hear when ever the brakes are depressed, and is quite loud when you stick your head close to the brake pedal. I tried to source this leak but was unable to find it. My thought process is/was:
With the brake light on/off and hissing noise, my mind goes to seals/loss of pressure. I removed the entirety of the brake assembly and disassembled each component. I found that the middle master cylinder oring was too short by about 2-3 mm, and that corrosion had built up in a small area in the top 'flange' area of the master seal. I've attached a picture that shows the corrosion and the o-ring that is too short and also too large diameter wise to fit snugly on the fitting. I was able to source a tapered gasket at O'Reillys that is an exact fit here since the repair kits are NLA. If all works (it makes a nice sucky sound!) OK I'll post the brand/part number in case it helps anyone out. All the other seals and bores look quick good with the exception of quite a bit of gunk built up inside, leading me to believe this car has never had its brake fluid changed in its 32 years of life. I also assumed the accumulator sphere is original and have replaced that as well.
Since I had the assembly out, I stuck with the jag mantra and "while I'm in there" will rewire the solenoids with 22AWG silicone wire, despite the ribbon cables being in better than expected shape.
Let me know if I have went awry in my path!
Originally Posted by orangeblossom
Hi LAJ
I think those figures are only meant as an indication
Sorry if I'm reviving an old thread, but I'm in the same boat. Picked up a 94 XJS that sat for 14 years and was putting new rear pads on it and compressed the calipers without opening the bleed valve like I've done on every car I've owned. After that my front left caliper its the only wheel that wants to stop after hitting ABS 3-4 times and send me into oncoming traffic. Re bled the system and it worked for the first 3-4 stops then the symptoms came back. If I disconnect the ABS module it will work like a more conventional brake system minus ABS of course, both fronts will lock up.
My question is has anyone just tried taking off the ABS block and blowing it out with compressed air? If I have to buy a new master and ABS module I will, but wanted to see what my prospects are for just trying to clear it with air? Does anyone know of a shop in the Los Angels area that rebuilt ABS modules?
Thanks for any help.
You could call Gary at Jagbits.com. They are in Hollister and he sells the rebuilt actuator/ block assembly. I know he gets them rebuild in the area. He might be able to help you or sell you an ABS block. They are easy to swap out if you you can get a good one. Not that I know if it would help, but when I took my first one apart from my much neglected ‘89 it was a mess and never would have worked. I tried using an XJ6 block with the XJS front plate, but never got far enough with that assembly to see if it actually worked.
You could call Gary at Jagbits.com. They are in Hollister and he sells the rebuilt actuator/ block assembly. I know he gets them rebuild in the area. He might be able to help you or sell you an ABS block. They are easy to swap out if you you can get a good one. Not that I know if it would help, but when I took my first one apart from my much neglected ‘89 it was a mess and never would have worked. I tried using an XJ6 block with the XJS front plate, but never got far enough with that assembly to see if it actually worked.
If the problem happened only because of pushing fluid back to the ABS valve block, then it could be disturbed sediment that's holding a valve open.
However, if the car hadn't run at all for 14 years, then it could be a variety of deterioration problems, including the sensors or the ribbon cable in the valve block.
Just IMO, it won't be a problem with the Actuation Unit. They generally never go wrong.
Don't just start replacing items until you definitively know what is wrong. If the car sat for 14 years, I would thoroughly flush the brake fluid. And you must do it using the the Teves procedure, not the Jaguar procedure.
Then do the Blink Test and see what shows up. Then do the 32 continuity tests and again, see what comes to light.
If the problem happened only because of pushing fluid back to the ABS valve block, then it could be disturbed sediment that's holding a valve open.
However, if the car hadn't run at all for 14 years, then it could be a variety of deterioration problems, including the sensors or the ribbon cable in the valve block.
Just IMO, it won't be a problem with the Actuation Unit. They generally never go wrong.
Don't just start replacing items until you definitively know what is wrong. If the car sat for 14 years, I would thoroughly flush the brake fluid. And you must do it using the the Teves procedure, not the Jaguar procedure.
Then do the Blink Test and see what shows up. Then do the 32 continuity tests and again, see what comes to light.
Good luck
Paul
Hey Paul thank you for your input. It did happen just after I did the rear brakes, I've since put new rotors, braided hoses and had the calipers rebuilt on the rear. have new hoses for the front but still sorting through this problem. As I mentioned if I pull the ABS plug its drivable like normal but will lock up the wheels if I hit it hard, with the ABS hooked up no way darts left. The one thing that was odd Is trying to bleed the front I had trouble getting much fluid out of the front left even with a pressure bleeder. I did do the Teves bleed for the rear.
I'm not familiar with the blink test or the 32 continuity test, but I'll look it up, is it in the manual? With the ABS plugged in I get no warning lights at all.
I was going to try 12v to the pins on the ABS block and see if I can hear the ticking people describe.
Toby
If one of those Valves isn't 'Clicking' then the Chances are that you have got a Broken Ribbon Connector
If you Car Violently pulls to the Right under Sudden Braking (not just drifting but trying to ****** the Wheel out of your hand) then there is even more of a chance its a Broken Ribbon Connector
A very easy and inexpensive Fix (in the Scheme Of Things) that will make it even better than when it was New!
A Shop could charge a Fortune for this if only they knew how but if you do this yourself it will be 'Peanuts!'
(1) Drain the Reservoir and have plenty of Old Towels at the ready in order to keep any dripping Brake Fluid off the Paint or it will Strip it!
(2) Undo the 4 Bolts that secure the Master Cylinder Actuator to the Fire Wall and disconnect the Plugs
(3) Don't bother removing the Reservoir just lift the whole thing out in one piece
(4) Lay the Master Cylinder Actuator on its Side so that the Valve Block Cover is uppermost
(5) Very (as in very, very Carefully, remove the Cover and look inside) where you may see the Broken Ribbon Wire
(6) Take Photos and make a little sketch of what Ribbon goes where
(7) Put the Cover back on just finger tight
(8) Take the whole thing to your Local Radio/Shack and again very Carefully remove the Cover in front of them, making sure to tell then that if they turned it upside down all the Valves could drop out under their own weight
(9) Ask the Radio Shop to Re-Wire ALL the Valves not just the Broken one with High Temp Silicone Wire and then put the Cover back on
(10) That's it 'Job Done' $25-$50 then put it back in the Car and Bleed the Brakes!
Most Important before you Bleed the Brakes, you need to Bleed the Low Pressure Side of the System or else you'll be wasting your time
If one of those Valves isn't 'Clicking' then the Chances are that you have got a Broken Ribbon Connector
If you Car Violently pulls to the Right under Sudden Braking (not just drifting but trying to ****** the Wheel out of your hand) then there is even more of a chance its a Broken Ribbon Connector
A very easy and inexpensive Fix (in the Scheme Of Things) that will make it even better than when it was New!
A Shop could charge a Fortune for this if only they knew how but if you do this yourself it will be 'Peanuts!'
(1) Drain the Reservoir and have plenty of Old Towels at the ready in order to keep any dripping Brake Fluid off the Paint or it will Strip it!
(2) Undo the 4 Bolts that secure the Master Cylinder Actuator to the Fire Wall and disconnect the Plugs
(3) Don't bother removing the Reservoir just lift the whole thing out in one piece
(4) Lay the Master Cylinder Actuator on its Side so that the Valve Block Cover is uppermost
(5) Very (as in very, very Carefully, remove the Cover and look inside) where you may see the Broken Ribbon Wire
(6) Take Photos and make a little sketch of what Ribbon goes where
(7) Put the Cover back on just finger tight
(8) Take the whole thing to your Local Radio/Shack and again very Carefully remove the Cover in front of them, making sure to tell then that if they turned it upside down all the Valves could drop out under their own weight
(9) Ask the Radio Shop to Re-Wire ALL the Valves not just the Broken one with High Temp Silicone Wire and then put the Cover back on
(10) That's it 'Job Done' $25-$50 then put it back in the Car and Bleed the Brakes!
Most Important before you Bleed the Brakes, you need to Bleed the Low Pressure Side of the System or else you'll be wasting your time
Ok Just did a quick pin test and 2 of the valves don't click the one closest to number one pin( the wire that doesn't move and in my case closest to the front of the car) and the one furthest from the number 1 pin, closest to the firewall on a US car. Not sure what each valve does but sounds like I'll be pulling the master out and inspecting the ribbon cables.
Toby
Thank You Alex,
Going to try the click test now as we'll as the blink test I saw on `Jaguar XJS OCD YouTube channel.
Thank You!
Hi Alex,
Quick question for the low pressure bleeding procedure, for the feed line to the pump, to me it dosent seem like its gravity fed because of the travel of the line being parallel on the fire wall and it seems like the fluid is coming from below the pump verses higher( like you might see in a syphon) because the pick up is so low on the reservoir. Did you pressurize the reservoir?
Toby
04-28-2022, 04:54 PM
