Caliper interchange?

[nevermind65]

Hello,

My Cobra has a Jag rear-end and the calipers are a very old style. From what I can tell, they came off either a MK-150 or a Series 1 XKE. I was wondering if I can get the newer style calipers and bolt them on without major modification?

Anybody know anything about these?

Thanks,

Ron

[ERA Chas]

Ron,
Contact Mike Bontoft at CWI Industries. He has a "bridge kit" which widens your existing calipers and supplys wider vented rotors from a Cosworth Sierra (I believe).
I have been very happy with mine from the mid-1990's. Fit perfect and much better than stock non-vented Jags. Work fine with my front Wilwoods.

[Pete Munroe]

Ron,

Why do you want late model calipers? What is the problem?

Are your early stock calipers leaking? Are you getting brake-fade and want to upgrade the rotors from solid to vented?

Stock Jag solid rotors are 0.50 inches. The after-market vented rotors from CWI are 0.870 inches

If your old calipers leak, maybe have them sleeved or get replacements. To
upgrade to the wider caliper you will need the spacers, "bridges" to widen the caliper.

CWI did my rear and it has the "bridged" Girling calipers and the thicker, 0.870, vented rotors.

Without the rotor upgrade, I'm not clear as to the advantage in swapping early for late model calipers.

What are the disadvantages to the early units against the later model versions?

Just asking to make clear why you want to change out the early calipers, the rear ends are a lot of work to play with!

Pete

[nevermind65]

The later style calipers are more plentiful and I can go just about anywhere and pick them up. I didn't realize I would have to change the rotors etc. just to make them work.

I'll probably just end up replacing the caliper cups as it is rather easy to do with this style caliper.

Thanks for the information.

[Pete Munroe]

Nevermind...

If you have a 0.50 rotor, and the late model STOCK Jaguars still use a 0.50 thick rotor, you could probably go the newer caliper design unless some other parameter has changed too.

The bridged or wider calipers are only necessary for the thicker, ventilated rotor, not the stock solid 1/2 inch rotor.

The ventilated rotor, at 0.875 is to the best of my knowledge a aftermarket piece...I do not think/know for sure if STOCK Jag sedans or E types ever came with the thicker rotor.

Some guys that know more about Jag stuff may have something to add.

Pete

[strictlypersonl]

It's difficult to change from the early one-piece Girling caliper (with separate bolt-on piston housings) to the late model calipers. The mounting system is different, I believe all the way down to the differential casting. I think it can be done with a custom bridge, but I'm not positive. I don't think CWI's kit will work with early caliper design, since the basic caliper is not split down the middle.

The later calipers are much cheaper to rebuild though. $10 pistons vs $50 pistons.

[nevermind65]

Thanks for the info. It does look as though the mounting positions are different from the pictures of the later style calipers.

Do you happen to know if the caliper pistons can be disassembled? If so, maybe I can just have new ones made out of stainless.

Thank you!

Ron

[strictlypersonl]

I'm pretty sure that Stainless Brake Corporation used to rebuild the old calipers. Worth a try.

[Maurice Butler]

check out Jaguar E-Type and XJ Inboard Brake Upgrade
and Stainless Steel Brake Caliper Pistons
all the xj6/12and s were closely related with a lot of parts interchangable

Also has lot of good info on jag suspension

[nevermind65]

I visited that site, unfortunately, most of their literature does not go back that far. The XJ's used a different style caliper, which I would have liked to have replaced mine with. I don't believe this is possible without major work. Maybe next winter I'll dig into it more. For now, I'll just throw a rebuild kit in the calipers and use them for the summer.

Originally Posted by Maurice Butler

check out Jaguar E-Type and XJ Inboard Brake Upgrade
and Stainless Steel Brake Caliper Pistons
all the xj6/12and s were closely related with a lot of parts interchangable

Also has lot of good info on jag suspension

[767Jockey]

Originally Posted by strictlypersonl

It's difficult to change from the early one-piece Girling caliper (with separate bolt-on piston housings) to the late model calipers. The mounting system is different, I believe all the way down to the differential casting. I think it can be done with a custom bridge, but I'm not positive. I don't think CWI's kit will work with early caliper design, since the basic caliper is not split down the middle.

The later calipers are much cheaper to rebuild though. $10 pistons vs $50 pistons.

Bob,
I've got the one cast aluminum Girling Series II calipers. I believe theones you are talking about, the one piece Iron caliper with the bolt in aluminum cylinder housings were Dunlop Series I, not Girling's, no?
What do you guys at ERA use for your Jag based rear ends? Do you go with the stock Dunlop Series I's, the stock Girling Series II's, or some aftermarket setup? Solid rotors? Vented? Where do you get your calipers? Can I purchase calipers from you? Any info is appreciated, it ain't always easy working on an orphan! Thanks.