I was finally able to get the rears to lock but only for a second. Had to pump the pedal once and hit it pretty hard. Then the RWAL dump circuit took over and the pedal dropped 1/4 inch and shut them up. [:'(] Stupid RWAL dump circuit.

At least I know they're working now.

 

Ok ... latest update. Got up this morning and grabbed a big common, slid under the back and adjusted the rears. Tightened up the stars until they wouldn't go any more (didn't raise the truck) and then backed them off three "clicks". Figured that would be about right. Pedal feels normal now and the truck stops a lot quicker with no lock-up at lower speeds. I say at lower speeds because at speeds over ... say ... 40 or so, harder stopping draws howls from the rears (but only for an instant ... then the dump circuit activates). No pump necessary.

Can't tell you what happens when it's wet because I haven't seen rain for months and probably won't for a while. Might be scary. [:-]

 

I was wondering if anyone knew the bore size of the 1500 wheel cylinders. I just thought that 1500 owners might want to go with dodge 1 ton wheel cylinders at 1 1/16" (27mm) instead of the GMC ones at 1 3/16" (30mm). That of course would depend on what size the are on 1500's. If the dodge 1 tons are an improvement over the 1500's it might be a better fit for the smaller 1500 drums and pads than using the GMC 1 ton dually's.

 

According to the parts diagram at RockAuto they're 15/16". Sure ... the 1-ton Dodges are an improvement but ... ehhhh ...

What do you mean ... "better fit"?

 

I was just thinking better fit as in better match to the smaller brakes on the 1500. You would still get better braking but might not activate the RWAL dump valve as much. I'm looking at doing the mod but am a little worried it might be too much in the winter on snow and ice. I'm not known for being light on the gas or the brakes.

 

Even though the shoes had about 1/2 the material left on them, the right drum wouldn't go on until the adjuster was backed off ALL the way. Even then, it was a TIGHT fit! I wonder what I'm going to do when I need new shoes now.

If this is a 'typical fitment issue', I wouldn't do this mod.

 

But once the drum was on and everything settled in I had to feed 4 or 5 full revolutions into the star adjusters (both sides) in order to set the shoes against the drums. The left side slipped on with no issues at all. Remember ... when the wheel cylinders arrived, they were of two different styles? The one with the internal seals is the one that gave me trouble. I couldn't get it to "press in" like the other side. I've already got a plan for shoe change in the future.

I was discussing the mod with some buds at work and one of them has fitment issues with his STOCK shoes/drums on his F250 ... exactly like I had on the right side here. He slips the drum over the rear shoe and then has a helper push the front shoe ... um ... down ... back ... in ... you know ... against the post, with a broom handle or something so it will clear the drum face. THAT'S the problem I was having ... but I was trying to do it by myself.

 

I use Hi-Lock whenever it's slick out (rain or snow) so I'm not too worried about RWAL doing much of anything then. I was even considering re-plumbing the system to bypass the anti-lock. That's how much I hate not being in control of what my truck does. When I stomp on the brakes, I don't want some computer telling me, "Sorry, you're rear tires are locked up. I'm going to dump the pressure now". Yeah? Well ... maybe I WANTED them locked up! [8D]

 

I agree! That's why I was thinking of going with the 1 ton dodge wheel cylinders, only because I was looking for a nice, cheap, and easy mod. If I go with the GMC 1 ton mod amd the RWAL kicks in lots then I'm sure it would get on my nerves real quick. Then you know it would be time to mod the RWAL which defeats the nice, cheap, and easy mod I was going for.

 

The Rom mentioned going with the Dodge 1-tons at one point in the other thread but I'm never one to go half way. I wanted to see what the big ones would do. So far, I'm happy as hell. Let's see how happy I am when it's wet out.

Two points ... 1) I'm running this thing as hard as I can, TRYING to get it to mess up. This is a test. 2) All this is being done in an unloaded condition. This mod is designed to assist the anemic braking of a fully loaded truck. I need to find something that A) weigh's about 800 pounds and B) is really cheap (like free).

The RWAL doesn't kick in a lot. Only when I TRY to lock `em up. Under normal braking in traffic, everything feels as it did before ... well ... except the truck stops with much more confidence. You just toe the pedal and you feel it starting to back off ... get a little more aggressive and the thing stops like it really WANTS to. You have to STAB the pedal to get the rears to attempt a lock.

I really want one of these: http://www.mirafiori.com/~courtney/1...rop_valve.html

I would reroute the lines up behind the dash so I could have the brake control right there.