Disc Break conversion

[Kittrell]

Tera manufactures at least the brackets themselves. But since the Ford 8.8, Jeep ZJ D35/44, Jeep KJ 8.25, Isuzu D44, and Tera Flex disc kits all use the same parts; I imagine the calipers, pads, and ebrake internals are from one of these axles.

 

[MudDawg]

I used the TSM kit...it made all the difference in the world on how the heep stops. I can make my 33's howl now.

 

[Dirk Pitt]

I notice slightly better braking on pavement, but the difference is night and day on the trail.

My drums used to fill with junk off-road and stop working completely. The ZJ disks work much better than drums when they've been dunked in mud/water/whatever.

 

[AJsArmor]

This is probably a stupid question, but if a lot of the parts in this kit are similar to an 8.8 for $450-500....why not swap in a complete 8.8? You get a nice beefy axle upgrade in the process and should be able to do it for the same or less money.

Guess it depends on the prices of 8.8's in your area. We've been seeing them for around $125-150 with down to 4.10 gears, complete. Perches, driveshaft flange and brakelines for under $100 total and you're nearly done for a total of under $300.

 

[comanche91]

Re: Disc Brake conversion

My rig is a 91 MJ, and until I replaced the original single diaphram booster and master cylinder with a new dual diaphram 96 booster and master, I could not lock the rear disks up either w/o a lot of pedal pressure. Also I had to play with the rear proportioning (height sensing) valve the MJ has on the rear axle. On the XJs, the prop valve is up front under the master; sometimes these get clogged and/or need the O-ring removed from the piston to get proper brake biasing. Someone else can chime in on that who has experience. Now with the TeraFlex kit and the 96 booster/master, with about 50% less pedal pressure I can lock up the wheels. Here's a good writeup on the booster upgrade: http://www.madxj.com/ in the Technical section.

To replace the pads or disks in the TeraFlex kit 97 Ford Explorer parts are used. Before you purchase any TeraFlex product, give Bob a call below. He usually beats everyone's prices and the service is topnotch.

Bob Supplee 4WD Enterprises, Inc.
3615 E I-240 Service RD
Oklahoma City, OK 73135
(405) 799-8977
[email protected]

 

[Beetlejuice]

You guys think an older 8.8(like off a 88 cougar) disc brakes might work? Or is that too old?

 

[balloo93]

Then just swap the whole axle in. No point in robbing parts off the better axle when you could just put the complete piece under your rig, and make more then just a brake upgrade...........:lecture:

I have a 29spline 8.25 in the garage on jack stands waiting for a regear. No point in having to cut, work out the pinion and weld perches, get spacers, and get another yoke adapter when All I need is the disc setup.

If I planned on running bigger the 33's I might consider it. The guy I know that has acess to them has never seen a 4.10 geared 8.8 either. He has 3.73 and 3.55's all the time though.

I figure buy the 8.8 for $250, take the brakes off and sell the remainder of the axle for around $100 and that gives me disc for $150! Just need to know if the caliper mounts will put the caliper on the rotor where it's supposed to go.

 

[Kittrell]

The 8.8 is closer to the XJ flange pattern. If you have an 8.25 you want the ZJ backing plates...............:lecture:

 

[gregmondro]

Regal, if you want the disc brake conversion (ZJ discs) i'll be happy to sell you one. PM Me

 

[balloo93]

The 8.8 is closer to the XJ flange pattern. If you have an 8.25 you want the ZJ backing plates...............:lecture:

Can't find a yard that will sell me just the brake setup and also can't find a gran cherok axle as cheap as $250. I think the yards feel because it has the term "grand" in it that they should jack teh price up. A yard recently quoted me $600 :twak:

 

[gregmondro]

Balloo, you too

 

[[email protected]]

Well as mentioned before the kit is on and works ok but i dont think there is enough pressure getting to the rear brakes. I am thinking of putting an adjustable proportioning valve from Summit. Does anyone know what size or model number valve will work on our application? I can't imagine that all prop valves have the same fitting sizes. Let me know what you guys think. If i can adjust it and send a little more pressure to the rear i will be fine tuned. Thanks.

 

[gregmondro]

what year is your jeep?

you might be able to take out the ring in your current one.

 

[[email protected]]

It's a 99. The peddle is a lot easier to press and the system is much smoother. If i could just get more pressure to the back.

 

[comanche91]

Check out GoJeeps solution.

http://www.go.jeep-xj.info/HowtoPvalve.htm

 

[Fred85]

Anybody know if the Explorer rear disc setup would work on a 8.25?

a tweety bird told me that the hard line flare style is different than the ZJ's

 

[[email protected]]

It seems like everyone who does this conversion also puts a grand cherokee prop. valve. As mentioned i want more pressure to the rear but i am having a hard time finding a adjustable prop valve that would fit right on. So my question is if anyone knows how much more pressure the grand cherokee valve will send to the rear over my stock valve? (It's a 99) Thanks

 

[comanche91]

It seems like everyone who does this conversion also puts a grand cherokee prop. valve. As mentioned i want more pressure to the rear but i am having a hard time finding a adjustable prop valve that would fit right on. So my question is if anyone knows how much more pressure the grand cherokee valve will send to the rear over my stock valve? (It's a 99) Thanks

No, not true. Most pull the front O-ring first from their existing prop valve to see if it helps biasing more pressure to the rear brakes first. Why don't you try this first? Easy and costs nothing.

 

[[email protected]]

Ok new question on the prop valve. From what understand the stock prop valve is 50/50 under normal conditions and sends more to front under hard braking. Is this correct? Second question is what is the difference between the check valve and the o ring that so many say i should try removing? This i my daily driver and i dont want to do anything that jepordizes my safety on road. I have read around that if i remove the o ring the proportioning valve will deliver 50/50 to front and back and loses it's ability to differntiate pressure. Is this true or does the propotioning valve still send different pressure to front and back just at a higher pressure compared to stock? I am sorry this is going on so long but for what it's worth this thread has helped me make tremendous improvements to my braking system. thanks to all.

 

[comanche91]

There are several writeups around of guys removing the XJ prop valve o-ring to bias braking more for the rear after a disk brake conversion. Some say they love it and brakeing is more predictable, some immediately put the o-ring back in because the rear locks up too easily. The 1996 master cylinder/booster upgrade helped my brakeing as much as the disks; but not your problem since you have a 99. I personally would not permanently modify the prop valve on a daily driver, but I would try it to see if it helped at all. If it did, then I would go with a adjustable Wilwood valve (or some other manufacturer) and tweek the brakes like you want them.