Front Brakes Will Not Bleed!

very interesting, that makes sense. Thanks for the info! I suppose while I’m taking the MC off to bench bleed I’ll check to if that residual pressure valve is still in there.

 

I wouldn't think you'd have to remove the MC, you could do it on the jeep if you have an extra hand/foot. If you have fluid to the rear as you stated, then possibly remove the line on the mc to the front and see if you can achieve the same goal as "bench bleeding". I'd disconnect that line and use my finger as a "valve" and push the brake pedal by hand, watch the fluid level so you don't go dry. But you may have to remove the other line to the plunger will go its depth. eh, the calipers do take more fluid than the rear wheel cylinders. When I said use teflon tape on the bleeder threads; just enough teflon to seal the threads, a wrap or two.
dne'

 

Residual pressure valves 2lbs for Disc's 10lbs for Drums

NEVER USE TEFLON TAPE IN A BRAKE SYSTEM. The flares are what needs to seal not the threads the threads will never seal as the tube to Nut joint is not sealed.

 

It is easier to bench bleed with the MC installed. Take the brake line off, install a short piece of brake line and stick it in the reservoir. If you can gravity bleed the short price of brake line and then stick it in the reservoir, this will help. Start pumping brake pedal. Make sure the brake line is below brake fluid level, as you pump the pedal, brake fluid will move each way. You will eventually get the air out. Go to Youtube several videos on how to do this.

 

Semi metallic will not work at all. I originally tried them but could barely stop. Any idea what calipers you are using? I was able to find organic Raybestos pads.
Here is my thread from a long time ago, lots of info and help from this forum: D27 Disc brake swap on my 71'

 

Thanks for the link I’ll be sure to check it out and I’m not 100% sure what they are the part number doesn’t help a lot but they appear to be GM Calipers maybe off a 1/2 ton 70s-80s model.

And do the semi metallic pads not work bc the brakes are manual and don’t have enough power to make the harder semi metallic pads wear in properly?

 

Thanks for the Advice Steve I’ll be sure to check out the videos!

 

Yes. On the factory dual circuit master cylinders, the valves are behind these nuts:


They consist of a spring and a rubber cup.

 

Yes, the organic work so much better. I used 80's Chevy Calipers and I believe the P/N is on my write up Raybestos RRD52.

 

Awesome! Thanks man.

 

JZeber- did you have to add a proportioning valve for your swap?

 

Yes I removed the res valve in the M/C and added a 2# in line. I only added one to the front and never had a problem with the rear.

 

So you only had to add an inline 2lb residual pressure valve for the front discs (and left the stock 10lb valve for the rear drums) but you didn’t need to install a proportioning valve that diverts fluid to the front or rear?

 

That is correct.

 

Thanks, but I was thinking of the original single output type m/c. ????

 

Well this is a good question. I'm not familiar with the older ones, so I looked it up in the FSM. It's integrated into the primary master cylinder bore itself. The residual pressure valve is in the far end and is actuated by the piston return spring.

Info from the manual:







I imagine you could disable it for disk brakes by removing the valve/seat and using external ones. But if you're doing that, you should really be using a dual master cylinder.

 

I've learned something here, once again!

 

Update: I finally got the brakes bled, the pedal feels so much better now!

I pulled the MC off of the vehicle and took out the factory 10lb residual pressure valve and installed a wildwood 2lb valve (current PN: 260-13783) then I bench bleed the MC which I believe is a newer unit based on how nice it looked inside the reservoir. Put it back on and it bled a charm. Thanks for all the info and advice guys!!