Hi there folks, my brake booster seems to have gone again, and even though the last time I replaced it I used used parts from a high mileage car, I can't imagine two would go within two years of eachother, so I'm assuming my master cylinder is to blame. I'm having trouble tracking one down that doesn't cost a small fortune. I've seen that some people have used units from 1993 Mitsubishis, but the location of the lines on the top would require fabrication of new lines and I've never done that before. I've also heard of people using a ford truck unit in their cars, but can't find any specs/details on this. I was wondering if I could use a mc from a pre abs Series III and just fit the nozzles that allow the use of an external reservoir? Are there any other MCs that swap in? Anyone who's done the Mitsubishi swap, how hard is it to adapt the lines? Other than that anyone got a reliable source for an MC that doesn't cost an arm and a leg? Thanks in advance guys.

 

What is your car's engine size please? Has the car got ABS or not? Exactly what are the symptoms?

 

It's the 5.3 V12 pre ABS. Loud hissing, pedal goes to the floor, little to no braking power.

 

The hissing sound is a vacuum leak. Finding this is the first thing to do. It could be the servo (booster) diaphragm, it could be a leak in the vac line. Disconnecting and plugging the lines at various points and asking a friend to push the pedal while you listen will track it down.

The pedal going to the floor sounds like the master cylinder seals giving up. The M/C can be rebuilt at home using a seal kit, or new ones are available. I have a feeling that the Mitsubishi mod you mention is about changing the brake fluid reservoir, not to do with the master cylinder, but I may be wrong. I take it there is plenty of fluid in your reservoir?

 

Thanks for the reply. I know it's a vacuum leak, I'm assuming the brake fluid has leaked into the servo. I understand that hat can cause the vacuum leak. The Mitsubishi mc is different than the reservoir, I'm familiar with that swap as well, but it's not what I'm referring to. Several people have used eclipse or galant MCs in their cars. There is not much fluid in my reservoir, which further encourages the leak theory.

 

Dym, pic of my MC ,it is for a Ford Pickup truck around 1995!

the reason i changed ,was because my 1978 Xjs used a cast iron MC,(read HEAVY).

ford truck was Aluminum, 1/3 the weight.

as i remember it was a bolt in no mods, BUT ,except had to change line fittings to fit MC, all parts were available at local Advance auto store!

altho it seems there are some different piston bore sizes, so check your size carefully!

i use the remote resivoir with simple lines,(that are hyd. brake fluid resistant).

i may change to the Mitsu. resivoir mounted on top of cylnder! some times leaks occur, if there is clearence room, may give more room also!

 

Thanks so much, this is exactly what I was looking for. How did you change the line fittings?

 

Hi Dym

If its just the Master Cylinder you are looking for, I think you may find that the one from an XJ6 is exactly the same.

Ball Park $100 - $150 (New)

But Check it will fit beforehand, if you are buying On-line.

 

wrong thread

 

I'd kinda figured this. Hoping to avoid buying online so that I can get the job done this weekend. I don't see why it wouldn't fit, save for the fact that the XJ6 didn't have a remote reservoir. This would probably be the easiest route. Just gotta figure our how to get the remote reservoir inlet nozzles. Do you know if inlet nozzles are something I could acquire at an auto parts store, or am I just gonna have to very gingerly try and transfer my existing nozzles if I go this route?.

 

A couple more questions about the Ford Unit: It appears the MC in question is from a 1995 Ranger, correct? also, where did you source the inlet hose hookup nozzles you used?

 

Hi Dym

You can also buy an XJ6 MC with a reservoir already attached for around $150

I think they also fitted this MC to the XJ12

As for making up the Pipes, it is very easy as you can buy a Brake Pipe Kit for about $30 and a great big roll of Copper (Cupro) Tube for about $15

So plenty of stuff for you to practice with, as you are going to get a few that would not pass your Quality Control, in which case you just cut the end off and start over.

As for the actual fittings, most Auto Shops will have them.

I made all the Brake Pipes on my XJS and once you get the hang of it its easy.

See how I did it here: (about 3/4 down the page)

https://www.jaguarforums.com/forum/x...122634/page17/

 

The Jaguar M/C rebuild kit has them in, plus more importantly, the special thick round rubber washers they push-fit into, that go into the hole in the M/c top, that keeps the fluid in place.

 

Would the already attached reservoir clear the XJS' hood?

 

No, it will not.

 

Rats. Kinda figured.

 

Duplicated Reply

 

Well, the rebuild kit is on back order from Jaguar. The remote reservoir fittings seem to be mad e of unobtanium. Gonna head to some auto parts stores to see if I can find a solution today.

 

Anyone got any advice on getting the second piston out of the MC? I can compress it, but I can't seem to get it to more out.

 

compressed air , be careful it dont hit anyone near you!