Brake Proportioning Valves

[sewlow]

I know that these vehicles have crappy brakes to begin with, but since I've lowered my truck, I've been having rear brake probs. Not anything dangerous, just aggravating & annoying. They seem to wear out faster than any other vehicle that I've owned. And they howl. usually during a slow stop, or at any speed under about 10mph, when applied. Sometimes they sound like a semi's.
When these trucks come from the factory, the 2whl dr.'s sit higher in the back. Now when a drop of 4/6 is done, does the truck NOT have that weight transfer that it would have, when at stock height? It seems to me that instead of pushing the weight down on the front, my truck pushes the weight forward. This seems to cause the rear brakes to do more work than they originally did.
I've also talked to a few other guys with lowered C1500's, & they have had the same problem with rear brakes howling.
I've re-done the brakes twice trying to cure this. And I mean re-done. From the new backing plates out, incuding a new master cylinder, booster & lines. Including having the NEW drums machined even before they were installed!
The rear brake lines are not crimped off!
Would this be the time for a proportioning valve to be installed?
Does anyone have any insight into this?

 

[kevhill85]

Hummm??? I have no ideas.. Like to see what type of answer you get. I changed mine to disk in the rear and can adj my prop valve .

 

[sewlow]

That's where I'm at now. Try fixing this AGAIN, or keep the $$$ I'd spend on this & put it towards a disc conversion.

 

[stroker52]

take the drums off and sand the inside of the drum with 220 sand paper and do the shoes also... you have what we call the bus glaze going on lol.. i just did it to mine and it goes away for a while.. maybe buy you some time till you get the disk brakes...

 

[DRAGGIN95]

I agree with the above for a temporary fix until you can swap to rear disc's, I also have never had the rear adjuster's work correctly on these, so every few thousand miles I manually adjust out the back brakes to keep them nice and tight.

 

[sewlow]

I agree with the above for a temporary fix until you can swap to rear disc's, I also have never had the rear adjuster's work correctly on these, so every few thousand miles I manually adjust out the back brakes to keep them nice and tight.

No kidding about the adjusters. And there's not even a knock-out on the back of the backing plates. WTF?

When I was into H/C mtn. biking, I was told that every pound taken off the wheels, was equal to 3 lbs. off the frame. Sprung/unsprung weight & all. The 20's I run, are 30lbs. a corner heavier than the stock wheels & tires. Well, if the mtn. bike theory is true, then that's the equivalent of 360lbs. of unsprung weight added, that the stock brakes have to contend with, continually. Not only that, but the added weight is farther away from the center of the hub, multiplying the centrifugal forces.

So thats what I'll do. Pocket the cash towards the disc swap, sand everything down, and even take my mini angle grinder, & taper the ends of the shoes. Shoud be able to get me through a month or so, while I gather parts. Be prepared for more Q's!


Hmmm...360lbs...that's the equivalent to...either a whole lotta beer... or 3 HOT babes. Without the benefits. And more gas per mile. Damn!

 

[stroker52]

Hmmm...360lbs...that's the equivalent to...either a whole lotta beer... or 3 HOT babes. Without the benefits. And more gas per mile. Damn!

lmao thats a good way to look at it...

 

[stroker52]

hey sewlow you got any good pix of your rear wheels... i would like to see what kinda lip they have... thanks boss

 

[sewlow]

Give me a bit to find the pix.

I looked for a long time for a wheel that was 'timeless'. Got these from Steve's Discount Wheels'. Outa Chicago. Local dealers wanted $1500.00 just for the tires!!!. I told the guys @ Steves what I had, & what I wanted as far as size & widths of the wheels. They handled the rest. Somewhere around 10-12 days later they were at my door. Tires & wheels, mounted & balanced. For $1800.00. Shipping, taxes & duties included! I'd buy again from them anytime. Great people who answered all of my dumb-ass questions.

The wheels are 20", 8.5" & 10" wide. The tire sizes are 255/45, & 295/40. The side wall heights of the two different sizes are the same. With a little different off-set in the back, I could probably run 305's.
Boss 338's.

 

[sewlow]

http://i1086.photobucket.com/albums/j450/98GMC97CHEVY/boss33820in.jpg

I believe these are the 20X8.5's. Only pic I have close up.