I have recently acquired a 90 XJ6 with antilock brakes. Most of the time the pedal goes to the floor but occasionally you will get a little something. It appears it needs a master cylinder but I’m open to interpretation. Does anyone know where to get, a replacement/rebuilt master cylinder at a reasonable price? Thanks in advance for any information that can be provided.It appears to be full of fluid with no
wetness on the shop floor.

 

Have you tried bleeding the system?

 

I have not. The previous owner passed away and a family member indicated it needed a part that wasn’t available. With that in mind I just went with what seemed reasonable. Do they have any special bleeding procedures your aware of?

 

There's plenty of how-to's in the archive, just do a search. On my 94, you bleed the rears with the ignition on and the fluid bleeds through automatically. The fronts have to be done individually and of course when bleeding furthest away from the MC first etc.
Good luck. Pedal like you have means you have air in the system.

 

TECHNICALLY it is NOT a 'master-cylinder'. It's a 'brake actuator'.

I recently (a year ago) had to replace a customer's in a 1994 XJS 4.0 convertible.

Found a rebuilder on eBay and the customer bought it. I installed it and completed the repair.

Jaguar no longer offers replacements so it is a 'do-it-yourself' or 'get-a-replacement' type fix.(car is still stopping fine)

 

obtaining a car in this fashion makes it difficult to determine what caused these problems. I will do some vigorous bleeding with dot four brake fluid. Many thanks to anyone who has contributed.

 

Don't we use DOT 3 in our cars?

 

I thought my lid said dot4. Whatever the lid says it is what it gets. Whatever you do, don’t get old.

 

All ABS systems recommend the DOT 4 (or Super DOT 4) for the viscosity requirements.

 

this is my first attempt at bleeding such a system. The pump is building pressure and shutting off. I am getting no fluid out of the rear bleeders. I have even applied vacuum to the bleeder to assist fluid movement but to no avail when the pedal is pushed, there’s a whooshing sound coming from fluid reservoir area. Much pedal pumping has been done and the pump was getting extremely hot so I stopped for the day. Every time the pedal is released I see fluid moving back into the Reservoir from what appears to be a round formation on the back of the reservoir. is the pump building pressure and stopping the proper thing for it to do?