Question for XJ brake gurus...

I had a minor disaster with my XJ on Saturday, and ended up breaking the driver's side steering knuckle. A local guy was nice enough to part out an axle he had for sale for me, so I now have knuckles, hubs, rotors, and calipers from an '88 on my 2001! Is there any advantage to this style over the newer version? I know I get rid of the composite rotor, and I like the way the calipers mount on this set-up. It seems to work well, and the rotors and pads are brand new!
Do I NEED to change it back at some point?

Well...

Right now you have '88 brakes on one side and '01 on the other? Those are two different systems, you should make them the same.

Personally I'd keep the newer style brakes, I plan to upgrade my '89 (the same brakes as an '88) to roughly '96 brakes, very similar to yours. The newer brakes stop better, so I'd stick with them. You can get cast rotors for the '01 I believe, it just takes some looking around.

So..yeah..I'd go back to '01 but ditch the composite rotors in favor of cast.

Sequoia

GSequoia said:

Well...

Right now you have '88 brakes on one side and '01 on the other? Those are two different systems, you should make them the same.

Click to expand...

No, I changed over BOTH sides; knuckles, hubs, rotors, and calipers.
What makes the newer ones stop better? I'm curious...

I don't beleive the newer ones stop any better due to calipers, etc. Only the dual diaphram booster which started in 1995 makes any difference. Michigan Highway patrol tests in 1992 showed 151' stopping distance and a 2000 road test showed a stopping distance of 146' with the dual dia booster so don't worry about the early calipers.

The later knuckles are a lighter weight one piece casting, and do not have the removable caliper mount, and the brake pads are of a slightly different size. The later pads are slightly longer, but thinner, compared to the early pads (IIRC). The surface area of the two pads look to be near identical, the piston area looks identical as well (I have not gaged either piston so a small difference may exist).

FWIW, I have both sets of knuckles and decided to stay with the early knuckles, and hub/rotor/pad set-up on my 88, because they look stronger when compared (side by side). I was ready to trade to the later knuckles as well, after blowing an early knuckle apart, but the information regarding the possibility of a significantly larger later-model brake system proved invalid.

There looks to be no brake area advantage to either pad configuration, only a cost advantage to manufacturing the later DC design (compared to the early two-piece K-H design).

The early Kelsey-Hayes knuckle has/had the advantage of larger aftermarket bolt-on caliper mounts, and calipers. I do not know if these parts are still available (or an advantage over the more recent WJ knuckle and brake upgrade).

If anyone wants to trade up to the later knuckles, or has early spares thay cannot use, I am willing to trade the 97 knuckles I have for early knuckles (for my trail spares cache).

Second that, one more plus you get with the earlier hubs is that they are rebuildable by changing out beraings and seals.

If you want more stopping power switch to the 96+ brake booster or go hydro boost. Hydro boost will give you real braking even with the largest tires

I guess you did ok then Bill.....You got the old school HD brake hardware and the new style brake booster...Its all good!