Disc brake proportioning valve?

[rocmoc]

I am completing a front drum to disc brake conversion on my '69 CJ5 . I am installing a '78 CJ7 Dana 30 with the factory disc brakes. I have the '78 disc brake proportioning valve & lines. Should I replace the stock drum valve with the disc valve or does is matter in this setup?

Thanks,
rocmoc n AZ/Mexico

 

[gert]

yes you should, there is a difference in them. If you look at the aftermarket kits they send you a new porportioning valve and a new master cly

 

[rocmoc]

Thanks I knew it but wanted someone to confirm. I already have a master cylinder upgrade but just in case I also have the master that was part of the complete setup.

rocmoc n AZ/Mexico

 

[gert]

as long as your master clyinder is made for a disk/drum set up your good. The drum/drum master clyinder has a residual pressure valve in them, the disk brakes do not need the pressure valve

 

[rocmoc]

Yeah I forgot about the valve. The proportioning valve has it on the output for the rear line. Looks like I am changing out the master cylinder also. THANKS!

rocmoc n AZ/Mexico

 

[BajaEdition]

I cut in an adjustable p v from summit racing into the rear brake line when I set my 67 up with disc all around

 

[Purple77CJ7]

as long as your master clyinder is made for a disk/drum set up your good. The drum/drum master clyinder has a residual pressure valve in them, the disk brakes do not need the pressure valve

You can pull the tube seats out of the master cylinder. Screw a sheet metal screw into the rear tube seat and pull it out. Use needle nose pliers to pull out the rubber residual valve and spring, then reinsert the tube seat. You don't really need to change out the master cylinder.

 

[rocmoc]

You can pull the tube seats out of the master cylinder. Screw a sheet metal screw into the rear tube seat and pull it out. Use needle nose pliers to pull out the rubber residual valve and spring, then reinsert the tube seat. You don't really need to change out the master cylinder.

OK I have to go with my current master cylinder as there is not room to use the CJ7 master and the output on the CJ7 master is on the wrong side up against the frame. SO, I have to do what you have posted. Is the residual valve in the outlet port for the lines to the proportioning valve? That is my understanding from your post but I want to be sure before I rip into the master. Also I am disc/drum, disc in the front with drum in the rear. SO, I only want to take the valve out of one port. Is there a preference? Looking at the CJ7 setup it appears the front, most forward port was used for the drum brakes.

Thanks,
rocmoc n AZ/Mexico

 

[Purple77CJ7]

Yes, the residual valve in behind the brass tube seat of the outlet fitting. I think your are right that the front port is for the rear brakes. Theard a screw into the tube seat and carefully pull or pry it out with a screw driver. The residual valve will be right there to pull out along with a small spring. If you bugger up the tube seat you can get new ones from an auto parts store. If it is still good push it in and use your fitting to seat it in the port.

 

[rocmoc]

Thank you Purple77CJ7

Thank you everyone

rocmoc n AZ/Mexico

 

[rocmoc]

I want to thank everyone again & the site for the help installing a '78 CJ7 Dana 30 with disc brakes in my '69 CJ5 .

I have installed the Dana 30 and I have brakes, steering & a driveline. I had to use all the '78 CJ7 steering components from the steering knuckle forward. Worked perfect, even clears the shocks. I used all of the CJ7 brake components except the master cylinder. This includes the lines. Works perfect so far. I have not had a chance to take it on the street as I still have to do the wiring. VERY PLEASED! I read a lot of other posts from past topics and people doing similar mods. I did go thu the Dana 30 and added a Eaton/Detroit Tru-Trac & change the ratio to 4.88. Thanks again!

rocmoc n AZ/Mexico