I bought a 1990 xj6 for my son and they PO told me that he put new brakes on but they needed bled. So I get it home and start bleeding the rear brakes the rotors were so rusted it was obvious the brakes havent worked in a long time and I was getting nothing oujt of the calipers after pumping the brakes, the front bleeds just fine. Anyway I found the mineral oil tank and need that explained to me. And 1 of the lines were unhooked so I hooked it up and now I have fluid coming from the upper line on the passenger side, when I tracked it down I come to find out that whatever was at the end of that line is not there. Anyway I am just hoping someone can tell me why I have no rear brakes because I do not want to just throw parts at it. I look online for brake parts, and sites list a brake booster but I dont see a booster on my firewall like I am used to seeing so where is it? LOL I really need help.

Thanks in Advance
Tripp

 

You have an "XJ40" type XJ6. The guys in the XJ40 section can help you better than I can but I'll offer what little I know about them.....

I think the adjustable rear suspension, power steering, and power brake assist all run off the hydraulic (mineral oil) system. On some XJ40s the adjustable rear suspension ahs been replaced with conventional, non-adjustable parts.

The actual brake system is separate. I suspect the rear calipers are loaded with rust and/or you have an ABS problem. I *think* your car has the Teves ABS with a pump for the rear brakes...whicle the fronts operate conventionally.

I'm really talkin' out of my hat, though. I've never worked on a XJ40.

Cheers
DD

 

Thanks, I have a 1990 XJ6 soverighn. So the mineral spirits has nothing to do with the brakes, cool. I believe it must have all been changed because it has KYB coil overs on it now but it does have the sport suspension button. Ok I am assuming the ABS pump must be out then because the light is on, and to get it to stop you really have to stand on the brake pedal and I have bled the fronts. Maybe it is the power booster but I cant seem to find it.

 

Your won't find a conventional vacuum brake booster. Your car has a hydraulic boost system....of some sort.

Cheers
DD

 

Known here and elsewhere as the "XJ40"...which is the Jaguar engineering designation.

For a period of time in 1986 and 1987 the "old" XJ6 was being produced simultaneously to the "new" XJ6....the car you have. To differnetiate between the two the "XJ40" designation is used.

The style you have was in production until 1994 when the next "new" XJ6 was introduced...known as the "X300".

Confusing, I know.

Anyhow, this section pertains to the older cars. You'll get better info by posting in the "XJ40" section

Cheers
DD

 

Thank you Doug

 

Do a search within the forum. You are not alone with this back brake issue, and it has been fixed before. Get yourself the Haynes xj6 89-94 shop manual as well. Good luck and welcome to the forum.

 

Tgunner,

The line you found disconnected is most likely the rear suspension hydraulic pipe for the hydraulic rear struts that have been removed in favor of standard shocks. First thing to do is unhook it and reinstall the blanking plug in the valve block.
You won't find a vacuum booster because the brakes on the XJ40 are hydraulically assisted. Behind your master cylinder you will find what amounts to a hydraulic slave cylinder that provides the braking assist; but things won't work with the hole in the system made by removing the blanking plug and connecting that open pipe.

The first thing you need to do is restore the hydraulic system, then assess the brakes.

 

I am lost. The PO has the line plugged up with a clamp wheres this blanking plug grrrrrr I wish I had some pics, ordered a book but who knows when it will arrive.

 

The valve block is over the RF wheel, the picture will show the fluid lines.

There is also an S73 document covering the Power Hydraulic system somewhere on the forum.

Edit: I found it........

Well, scratch that, it says it's small enough, but it won't upload. Search the forum and you will find the Power Hydraulics book-S73.

Good luck!

 

I have nothing that looks like that. The only thing I have is the line going into the resevour for the castrol hydraulic fluid the PO had the line disconnected and a plug where it used to be connected. That line was for the suspension I assume, however the brake lines to the rear are hooked up the the master cylinder on the drivers side but i get no fluid to the rear but I do to the front brakes but I have to stand on the brakes to stop. Would it be the power booster and where is that, inside the master cylinder?

 

Tgunner,

Here are links to a couple of update documents that have a lot of information about the introduction of that brake system. It came out first on the '89 XJS, then hit the '90 XJ6. The XJS had the pump and accumulator across the car from the rest of the system, but it worked exactly like the sedan, just longer pipes. Look over them and you may get a better idea what's going on.

S60.pdf
S66.pdf

There have been a couple of times I had to leave the system powered up, use something to depress the brake pedal about 1/2 to 3/4 inch, remove the reservoir cap, and open the rear bleeders and let it set. Twenty minutes later the fluid started dribbling. Worth a try I 'spose.

Oh, I thank you for your service, Sarge!

Good luck!

 

Thank you for the info it is very helpful and your welcome