cruiser54

I'll assume relay is removed. C216_1 should have B+ voltage. Check voltage at C106_D1-5, should have B+ voltage. Check voltage at C103_B (Engine harness side), should have B+ voltage. Pls advise. Thank you...

You should have about 12 volts to the pump, not 6.97. Pull the relays and clean up their contacts and receptacles.

I thought I was going to have to when I did the disk brake conversion but I guess, and I'm no expert, when I did the 96 booster and MC swap theres enough pressure with the MJ block to get the rear brakes locked up. I haven't upgraded the front pads yet. When its time definitely going to black magic pads. Correct. Prematurely........

I've done 2 Comanches and 1 Cherokee with upgraded boosters. 1 Comanche has rear drums. The other has rear discs as does the Cherokee. On the Cherokee I just swapped out the prop valve guts from a 94 to 98 ZJ. Works great. First Comanche with rear drums disappointed me when compared to the XJ and gave me premature rear brake lock up. Added an adjustable prop valve to reduce lock up. Overall braking performance decreased. That's when I decided to do this like I've don on many others and delete the prop/distro valve and see what happened. The orifice in the distro valve is .050" whereas brake line tubing ID is .100". Using Ts and fittings from Napa I improved the braking performance a lot. I was able to put more braking to the rear with the adjustable valve than previously. Now it stops almost as good as the Cherokee. The other MJ that I plumbed the same way stops as good as the Cherokee.

If you decide to upgrade the booster/master, you will be flaring brake lines.

So you deleted the distribution valve or just the height sensing valve when you did the booster?

The booster difference is huge. You can also use a 99 to 2004 WJ booster/master.

I’d be looking up ABOVE first, and VERIFYING the source of the oil leak YOURSELF. Everybody, who doesn’t own or have to pay for or perform your vehicle repairs, loves to poke their noggin UNDER the Jeep and come out bearing the false bad news that your RMS is leaking. Many mechanics, friends, and good old Uncle Bob seem to enjoy telling you it’s the rear main seal. Has a catastrophic ring to it, doesn’t it? A simple leak at the back of the valve cover or other source could produce the same symptoms. You don’t need to be a mechanic to figure this out. If you have good eyesight and a dim flashlight, you’re good to go on your own. Don’t jump on the RMS/oil pan gasket bandwagon right off the bat. Almost any oil leak on your 4.0 is gonna drip from the RMS area for two simple reasons: First off, the engine sits nose-up and any oil will run back to the RMS area. Secondly, the RMS area is also the lowest point on the engine. Simple physics and the old plumber’s adage apply here: “Crap flows downhill”. Valve cover gasket, oil pressure sending unit, oil filter adapter seals and distributor gasket, in that order, have to be eliminated as possibilities first.

So, you want to keep the block and eliminate the height sensing valve, right? Plug the hole where the block gets it's signal from the height sensing valve? Tie the rear brake pressure line together at the rear?

I'd have to see it again. Not sure which is the problem for sure. I just know what fixed it I guess.

Still want photos?

Okay -- and now you have no brake system warning light. While I am well aware that anyone with half a brain should know if they've lost the front or rear brakes, I don't think it's legal to remove that feature from a vehicle that's registered and driven on public roads. And it doesn't gain you anything -- the MJ block that you eliminated doesn't have any proportioning function, so it's basically doing the same thing as the tee you installed. Correct on the first point and I'm the first to agree we shouldn't trust Don to drive a truck without that feature. Wrong on the second point. Where the fluid passes through the distribution block for the front brakes, and it goes right straight through, the orifice in the block is noticeably smaller than the inside diameter of the standard metal brake line running into and out of it. I ran mine that way for a while with the upgraded booster and master. I was disappointed in the braking power compared to my 88XJ which just required changing it's prop valve guts with the guts from a ZJ prop valve. So, I eliminated the distribution valve and put the tee in. That's when I noticed the difference in ID between the lines and the orifice. Brake lind ID is .100" and prop valve is .050"........ Keep in mind, this is not the first vehicle I've added rear discs to. Two Datsun Zs , two FJ40s, and a few others. You just let full pressure go to the front discs and regulate the pressure to the rear discs with the adjustable prop valve.

Well, whatever you wanna call it, the passage that the fluid must go through to the front brakes is very small. It wasn't until I $#!&canned that POS that my front braking improved so much that I had to increase the pressure to the rears so it wouldn't nosedive. Having done this both ways, I would never use that distribution valve again. Just sayin'..

Yes, this is the plan. Don't know about the "enjoy" part........ Will use a 1/2x20 plug with Teflon tape to seal the distribution block front/lower port; I see no need for hacking off a bolt. IF the rear disks lock too early, then I'll plumb in an adjustable prop valve. Rear drum and disk configurations are all different and require different amounts of biasing, or maybe none at all. Hoping for the latter........ You will most likely have early rear lock up.

I understand that. I've done this on 2 MJs. One with rear shoes and one with rear discs. That doesn't change the fact that the prop valve has small orifices to the front brakes.....

I did that initially. Rear brakes locked up early. What I found was the MJ prop valve has an opening in it for the front brakes that is quite a bit smaller than the brake tubing size. Eliminated it completely and had much better overall braking performance. Hence, my newer method for eliminating the factory crap.

Eliminate the factory prop valve. Using a T, join the pressure line from the master to the 2 front brake tubes. From the master cylinders pressure tube to the rear brakes, install an adjustable prop valve. At the rear, remove the height sensing valve and use a union to connect the lines together. Condemn the line that runs up to the engine bay to the old prop valve.

:hmm: And bypass the rear height sensing valve.

Oh yeah. I have that one now. Runs like a scalded dog!! For sale. Just it's not the Jeep in the video.

I think so.....

In the video? That's Brendan's 88 Cherokee.

I used an adjustable prop valve for the rear circuit for both drum and disc brakes on 2 of my MJs. Join the front lines and pressure tube from the master. Install the adjustable prop valve in the line to the rear. $#!&can the extra line.

Yes, we are planning to do more.