JB7 caliper upgrade?

[Nikkormat]

Does anyone know if we can run K20 JB7 calipers on our Jeep's? Seems to be a common upgrade for Chevy guys, but they claim it can only be done on 8 lug rotors. I seem to recall having read a post about running them on a Wagoneer by Elliot (hydroboost Elliot) over on the mother ship but can't find it now...

[az chip]

Elliot is on ebay. Sterlingworth 16.

[babywag]

Does anyone know if we can run K20 JB7 calipers on our Jeep's? Seems to be a common upgrade for Chevy guys, but they claim it can only be done on 8 lug rotors. I seem to recall having read a post about running them on a Wagoneer by Elliot (hydroboost Elliot) over on the mother ship but can't find it now...

Yes, they drop right in.

[derf]

I put them on the J20 axles under my truck. They bolted right up with a new set of Chevy spec rotors.

The Chevy 3/4 ton rotors are 317mm and the Grand Wag 6 lug rotors are 301mm. I don't know how well the brake pads will line up and whether you need a larger rotor or not.

[Nikkormat]

I put them on the J20 axles under my truck. They bolted right up with a new set of Chevy spec rotors.

The Chevy 3/4 ton rotors are 317mm and the Grand Wag 6 lug rotors are 301mm. I don't know how well the brake pads will line up and whether you need a larger rotor or not.

That's the concern, when I get around to doing this I'll have to mock it up and see how things align. There's also the issue of rotor thickness, I may need a spacer behind the outside pad to keep the piston from going too far out of its bore as the pads wear.

[derf]

Why not just upgrade to J20 axles?

[Nikkormat]

Why not just upgrade to J20 axles?

I want to stay six lug to keep the Bro Dozers away. I was going to go five lug but then people might think it's some kind of Ford!

[Nikkormat]

No offense to anyone's 8 lug Jeep of course, none of you are the reason for my 8 lug avoidance.

[Cecil14]

They fit fine, I've been running them for over a decade. This has been discussed over on the mothership for a long time now. The parts you need are:

Pads and calipers from an '85 Chevy 3/4 ton
Stock rotors

That will get you 3/4 ton brakes on the front.



aa

[toothofwar]

And will bolt up on stock rotors fine?

Sent from my SAMSUNG-SM-G891A using Tapatalk

[Cecil14]

That's what I've been running, no issues in the last 10 years or so. Stops better than it ever did from the showroom.


aa

[Cecil14]

Finally found it, here's the post from the mothership with the full details:

http://www.ifsja.org/forums/vb/showthread.php?t=177878

I believe you need different rubber lines as well, as the banjo bolt in the JB7s is larger than the stock calipers. I want to say there is also a little piece of metal to "clock" the hose on the caliper, I believe I cut that off. The calipers mount in a little bit different orientation on the chevy than ours, so that clocking puts the hose in a bad spot.

I can probably get some pics this weekend if someone really needs them, but honestly it was a really straightforward swap. If you're doing brakes anyway, there's no reason not to upgrade.


aa

[rocklaurence]

They fit fine and you will have to grind-off the clocking tab to use the Jeep brake hoses. By experience, install the bango bolt while griding off the tab because any nick on the seal surface will cause it to leak.