Disc/disc question.

[Jimbos76cj]

So I'm getting close to doing the brake lines on my jeep and came up with a question that I can't figure out myself and I'm hoping you smart folks can provide some assistance.

Switching from disc/drum to disc/disc. I know I'm supposed to modify the stock proportioning valve (PV). But since I'm running disc all around can I just remove the PV and run the lines directly?

But then I read that some residual pressure is needed in the lines and I need a PV for that.

Then I also see that I need to make sure the fronts take more of the stopping power compared to the rear to keep from doing donuts so I was thinking straight line to the fronts and adjustable PV on the rear line. But hat doesn't help with the residual pressure needed.

I did a search for pv's and found one for disc/disc brakes. Would that work?

I hate problems like these.. Any help is appreciated.

 

[Reddrig]

I just did a disc disc conversion. You need the PV4 prop valve. This is made for disc disc and will set the % for front and rear. You do need to use one in my opinion. You will have a hard time under heavy braking without one. I can post some pictures of my setup if you want.

 

[GatorBate]

I just did a disc disc conversion. I can post some pictures of my setup if you want.

I would like to see your pictures. I want to convert to disk also and would like to see how you did it.

 

[Reddrig]

Ok, I'll put some up later to day.

 

[tarry99]

So I'm getting close to doing the brake lines on my jeep and came up with a question that I can't figure out myself and I'm hoping you smart folks can provide some assistance.

Switching from disc/drum to disc/disc. I know I'm supposed to modify the stock proportioning valve (PV). But since I'm running disc all around can I just remove the PV and run the lines directly?

But then I read that some residual pressure is needed in the lines and I need a PV for that.

Then I also see that I need to make sure the fronts take more of the stopping power compared to the rear to keep from doing donuts so I was thinking straight line to the fronts and adjustable PV on the rear line. But hat doesn't help with the residual pressure needed.

I did a search for pv's and found one for disc/disc brakes. Would that work?

I hate problems like these.. Any help is appreciated.

The Correct Disk/Disk proportioning valve is needed. You also need to have a pair of 2 lb residual valves within the system.........some proportioning valves have that feature built in............
It should also be noted that your Master Cylinder should also be correct both in bore size and reservoir volume as Disc systems do require higher pressure and more volume to operate as compared to a Disc / Drum or Drum/Drum system............If your current Master Cylinder is the type that has a split reservoir where one half is larger than the other it should be replaced as the correct cylinder has equal sized reservoir's.

 

[Reddrig]

These are a few pics. Once I got my rig home, I ordered both the front and rear disc kits. I used the PV4 Disc/Disc prop valve, this is a all in one valve nothing else needs to plumbed in the system. I did need to plumb my brake light switch back in. I run a master cylinder and booster made for my system, I replaced everything new when I did the system. I used the two (already there) main hard brake lines that came into the engine bay, everything else was replaced at the t-fittings to the discs. The project was straight forward other the normal problems when working on a 43 old year car.

I'm also running a hub centric spacer on my wheels. This was based on the wheels I wanted to run and clearance, and they push my wheels out 1 1/12". I will be upgrading to stainless lines once my bank account catches up with these projects.

If you need a prop valve, I have an extra new one and will give you a good deal on it.

 

[IOPort51]

that is a very nice job. I like the PV valve up there, I left mine down on the frame. I also built a brace under the MC as I considered it a lot of weight to have bouncing up and down supported only by the fire wall.

and , of course I never miss a chance to show off the mother of all CJ rear axles.

 

[Reddrig]

that is a very nice job. I like the PV valve up there, I left mine down on the frame. I also built a brace under the MC as I considered it a lot of weight to have bouncing up and down supported only by the fire wall.

and , of course I never miss a chance to show off the mother of all CJ rear axles.

Also a very nice job, this is a great thread for someone considering disc brakes. I like looking at well done thought out Jeeps. I like what you have done. Great pics.

 

[IOPort51]

Also a very nice job, this is a great thread for someone considering disc brakes. I like looking at well done thought out Jeeps. I like what you have done. Great pics.

I don't think the idea of the thank you button was to acknowledge complements like that but thank you for yours and hey what the heck.

 

[GatorBate]

IOPort what disk brake kit did you use? It looks like yours has the E-brake. I can't tell from Reddrig pictures if his has the E-brake on the calipers or not.

 

[IOPort51]

IOPort what disk brake kit did you use? It looks like yours has the E-brake. I can't tell from Reddrig pictures if his has the E-brake on the calipers or not.

2570

this is what I used on the Dana 44 and they do have e brakes. the price tag looks high until you look at the price of the calipers rebuilt. they are about $300 each and these are new with pads so it ends up being very good price for the kit.