If you pull that off that restoration, amazing job!

 

heres another guy doing a rebuild.
http://www.nastyz28.com/forum/showthread.php?p=2797726

 

cheers, lets hope it works! now ive found the right guide images im quite enjoying this!

im off with my shopping list now to make sure i clean it up and reconnect it as well as can be.

-thread sealant (pipe dope)
-fine wire wool
-wire bottle brush
-multi sized o rings
-multi sized e-clips/circlips
-beer

my friends are trying to help out on facebook and sent me this:

 

Hello, so heres an update. ive put the valve back together, used some thread lock on a couple of bits which in hindsight i think I probably shouldn't have.

Anyway I'm now waiting for my local parts store to make up some new hard brake lines to replace the ones that snapped or got chewed up when i dismantled it. The issue now is that im in the UK and it looks like he'll have to reuse most of the original couplers to the combination valve as he doesn't stock those US sizes.

Does anyone out here know the EXAACT coupler sizes so i can source them myslef? The ones i'm after are the two that connect the master cylinder lines to the combination valve. and also the ones that go from combination valve to front drivers side brake line.

cheers

 

hello, so I've had to leave this fun project for a while, got my first child arriving soon and just started a new company too!

Anyway, I've reassemble everything, no apparent leaks just yet. had a day bleeding brakes.. still seems to be air in rear drivers drum so I've left that hooked up to a tube and half bottle of fluid to gravity bleed for a few hours. Meanwhile I've been looking into this soft pedal a bit further and found this: http://www.aa1car.com/library/abs_kelseyhayes_rwal.htm

its the one part i haven't looked into. i think ill give that an inspection as i quickly tried the brake with the engine on and its exactly the same.. could be that last bit of air but i expected it to at least improve a little bit! if its as crusty as the combo valve was then maybe the rwal valve is stuck open as described in that article.

 

Have you replaced all the rubber hydraulic hoses? There's one in the rear in addition to the two in the front.

Not sure it would account for the spongy feel but considering the corrosion you had in the valve I'd seriously consider replacing thme, if not all lines.

 

No i haven't, amazingly the rest of the system flushed out quite clean. I don't think I can take the RWAL valve apart like i dd with the combo valve.

re the rubber hoses - tbh I'm trying to conserve money on this at this stage but its crossed my mind.

I still need to finish bleeding the air. I've left it for a few days and I'm gonna go and do it again as there were some teeny tiny bubbles from the RL drum so I'm hoping they've settled into a nice big bubble.

 

after bleeding yet more air out the rear left drum i noticed its got a fairly new pipe on it which has a high arch in it to go over the diff case instead of across, in front of it. this i where i suspect it had a lot of air build up. I then disconnected the parking barake, and adjusted the rear shoes to just below "snug".

I had the rear wheels jacked up off the ground and tried running and braking the truck in drive and reverse and also applied the brakes at different speeds. Whatever i did it was always the same outcome.. the left rear would stop almost immediately and the right rear was slow to stop and most of the time didn't stop at all! if i mashed the pedal i could feel the rwal doing its job with several judders.

So i guess for some reason the rear right brakes aren't getting the fluid pressure. As daguvena88 suggested the problem might be the rear rubber hose. I'm going to remove it and inspect it tomorrow. I don't think it can be anything else science the cylinders are brand new? I don't think the diff would affect this would it?

 

So i had a look at the rubber hose T-section where it splits off to the left and right . I was hoping to see crud in there blocking the right junction but it was really clean, fluid ran out nice, i could bled it easily, I checked the solid pipe from the tee to the right cylinder and that seemed all nice too.

So with the rear off the ground why would the left wheel brake nicely but not the right wheel, in fact its not stopping at all now.!??

I'm gonna go and check again all the linkages and levers in there and see if something is getting caught up when the brakes are applied but i don't see anything unusual there so far.

Does anyone have any ideas what could cause such an imbalance?

I read somewhere that i should take it for a drive and smash the pedal a few times to even everything up but thats surely the same as running it with the rear on jacks.

 

drum brake needs adjustment
spring hardware is funky
worn shoe/drum
cylinder/pistons siezing

rubber hoses can look good but collapse/bubble internally under pressure