Wilwood rear brakes, prop valve and some issues.

[alex22]

I made a Wilwood rear disk kit work on my Ford 8.8 rear with an Alloy Super88 Kit and added a Wilwood adjustable proportioning valve in place of the factory prop valve. I also added a 3500 van master cylinder. Mistake #1, but that is now in my brother's big stoopid build.

Here are the part numbers I used.
Disk brake kit:
http://www.wilwood.com/BrakeKits/BrakeKitsProdRear.aspx?itemno=140-11396-DR
Non drilled/slotted option. The flange and seal needed to be remachined to make it fit and a shim to make up the difference in backing plate thickness (about .070") I'd have to look at my notes again but I think it was the kit meant for the "Big Ford" axle flange would have worked out of the box, or at least the bolt pattern would have been correct.
These fit under an 15" Alloy USA wheel.

Proportioning valve:
http://www.wilwood.com/MasterCylinders/MasterCylinderValves.aspx
Part number: 260-11179

Current master cylinder:
NAPA new stock replacement.

Front brakes:
Still factory D30 brakes and I'm working on another D30 with WJ steering and Akibono brakes.


So here's the problem I'm running into. The brakes feel like shit and even when I stand on them the jeep will just sorta slow down, not even lock up the backs. When I'm bleeding the backs (with my brother operating the pedal) the backs will allow the pedal to go all the way to the floor when I crack open the bleeder. Up front the pedal will only go half way down then stop. Here are a few pics of the under the hood setup for the proportioning valve.
The rest of the system looks pretty standard with SS DOT spec flex lines running from the axle to the calipers.
Did I miss something or is it plumbed wrong?

Intake removed for a better picture.






~Alex

 

[Jbh97009]

I would fiddle with the prop valve some more(unless you already have)

And just for sh!ts and giggles you do have the calipers on the correct sides right? (Bleeder at top of caliper)

I recently had to replace one of my front calipers because my bleeder screw stripped, no biggie I had an extra set of calipers so I swapped it out. Well I put the wrong side on so the bleeder was at the bottom and couldn't get the pedal hard to save my life.... Must have used 2 bottles of brake fluid before I started google(ing) and figured out what I did.... Crap happens. Just tryin to eliminate the easy stuff first

 

[alex22]

All of the bleeders are at the tops of the calipers and both the inside and outside of each rear caliper have been bled.

I tried the proportioning valve all the way in and all the way out. It does change whether or not the rears lock up when doing 20 to 0 on my gravel driveway but no difference in how far the pedal drops when bleeding the system.

Is the furthest forward output on the master actually for the front brakes or are the outputs flopped on the master?

 

[XJLI]

you have the lines wrong on the prop valve. i had it in my 98, its hard to see but look...

 

[XJLI]

heres another pic

 

[alex22]

Well F*** me, I did get it backwards.

:cheers:

Thanks.

 

[Talyn]

That is it. The front port on the MC does to the rear brakes.

 

[cruiser54]

Just a thought, but whenever I've done rear disc conversions in the past on FJ40s, Datsun Zs etc, I installed a simple one line in and one line out adjustable prop valve in the line to the rear.

I "married" the line from the master cylinder port for the front brakes directly to the line TO the front brakes with a union.

 

[Talyn]

That is pretty much what his prop valve does. Its just all one piece.

 

[cruiser54]

That is pretty much what his prop valve does. Its just all one piece.

Oh, okay. So, the rear proportioning has nothing to do with the pressure on the front brake circuit?

 

[Talyn]

Yes, the ports on his prop valve for the front circuit are just pass through.

 

[cruiser54]

Gotcha.