Does anyone have a source for parts to rebuild the master cylinder on 1994 XJ12? Mine is leaking and I really don't want to have to buy a new one. Thanks in advance

 

I have found on the internet that the master cylinders like I have are not rebuildable. I guess the search is on for a replacement

 

Hi Ron,

I just checked jaguarclassicparts.com and Jaguar shows a "valve block repair kit," part number JLM11336, still available (it's under the Unillustrated Parts):

Actuation Assembly and Reservoir - Parts For XJ6 & XJ12 from (V)667829 to (V)708757 | Jaguar Heritage Parts UK


Checking the part number at jaguarmerriamparts.com, the kit is shown as available, but it's USD $250.71, which seems far too expensive for a master cylinder kit.

I just looked up one of my old posts in the Jag-Lovers forum and found a part number JLM1477 for a master cylinder repair kit, and jaguarmerriamparts.com shows that kit is only $24.50. You would have to call to confirm that it will fit your '94 XJ12.

It would be well worth a few phone calls to the good independent Jaguar parts suppliers like our forum sponsors Coventry West, SNG Barratt and Jagbits, all of whom offer discounts to Jaguar Forums members. Also check with Welsh Enterprises and Jaguar Merriam (the dealer in Merriam, Kansas that sells Jag parts online at discount prices). For those further west, gaudinjaguarparts.com also sells Jag parts at discount prices.

Cheers,

Don

 

Don,
Thanks for the info. I will do some more research. Appreciate the help

 

what's it doing? where's it leaking?
I just replaced mine on myxj12 2 weeks ago.
the part before the "master cylnder" can't remember the name ATM, went bad on mine. and there are no parts anywhere to fix that thing.
I found a whole unit on ebay pedals and all for 170.

 

The pedal is ok at first if a little soft. When I hit the brakes the ABS light and the brake light come on and stay on until I let off the pedal. The pedal also goes all the way to the floor slowly. Also the part you mention that is between the pedals and the master cylinder is full of brake fluid.

 

Shawn,

Are the brakes on your XJ12 the Teves setup with the valve block/accumulator/electric pump/low pressure switch mounted on the right firewall?

Do Ron's symptoms sound consistent with master cylinder leakage only, or do you think he may have a problem with the accumulator, pump or pressure switch?

Don

 

Don, I changed the accumulator ball first hoping that was the problem. I can hear the pump running when the brake pedal is depressed. The pedal is not unusually stiff that I can tell which if I understand right, is one symptom of a bad accumulator ball

 

yep Don mines the teves setup.
I don't think its the ball or the pump/switch.
it sounds the same as my problem but worse.
the only thing you can do is find a whole unit.
I post my pic again it shows what went bad.

 

Is there a reason to change the whole assembly? Is there a reason I can't split the unit at the two torx head bolts? If I could do that it seems like it would be much faster and easier.

 

I tried at many wrecking yards.
couldn't separate them. and even if you did there's no gaskets you can get for it.
I had a hell of time trying to undo the pedal linkage. never was able to.
so I got a whole used asembly. had the whole old unit pedals amd All out of the car in 30 min it was super easy.

 

Ok Shawn. Thank you for the help. I have a master cylinder on the way so when it gets here I guess I will be under the dash for a little while.

 

Don, thanks for your help. It is greatly appreciated.

 

you're welcome.
Make sure you order the parts from a 91-94, pref 93-94. since they are newer ish.
If ya need any help sticking it all back in feel free to PM me.

 

I have just put the second ABS brake actuator on the car and bled the brakes. Still the same symptoms. Pedal goes to the floor and ABS light and brake light comes on. I have better brakes this time but still no solid pedal. I am considering an earlier braking system without ABS. I like the car but would like to drive it and not worry about brake failure. Any ideas?

 

if your just replacing the ABS actuator the part that all the brake lines come out of. thats not gonna fix the issue.
I thought you were getting the whole brake system as a used unit?

 

I replaced the whole pedal assembly. I have a solid pedal until I start the car. Then the pedal goes to the floor and the lights come on. It will not pump up which tells me it is not an air problem in the lines. Is it still the actuator or is there something I am overlooking?

 

hmmm im stumped aswell.
Does the pump go on and fill up the ball then shut off?
and when that is done "if its correcttly pumping" when u press the pedal do you hear anything? or does it loose pressure quickly and pumps comes back on?

 

Have not listened to see if the pump comes on when I turn on the ignition. Will check that tomorrow. As I said I have a very solid pedal until I start the car. At that point the pedal goes to the floor and will not pump up. I did notice if I hold the brake down it does come up a slight amount. I am assuming that is the pump compensating. I do have another pump that I am going to install tomorrow as well and see if that helps.
Will update you when I try that.

 

Didn't have much time on the Jag today. I did however notice a small crimp in the line going to the part Shawn had circled as the part that goes bad. It is not mashed flat but I am wondering if that could be causing the problem I am having. It is passing fluid I just wonder if it is restricted enough to cause the failure I am experiencing. I am still trying to figure out exactly how the brake system works. I think the line I am referring to comes from the pump across the car and provides the power assist. Am I correct?