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Brake proportioning valve...

If your going to keep the drums the steel braided lines will make a big difference. The other important item most forget to keep on top of is adjusting the rear drums at every oil change. If your getting over 100k out of your rear brake shoes them they are not adjusted right.
I use to rip mine down when ever I did the rear fluid to clean, grease and make sure the adjuster is turning freely. I always though it stopped great with the drums.
Even doing all this my rear disc setup is a big improvement though.
 
THEFERMANATOR said:
It made a big difference in my BURB. I know before I could bottom the pedal out when braking, now it will warp the rotors from being able to clamp down on em so tightly.
Click to expand...

Do you creep on your brakes after a hard stop or cook the rotors sitting in one spot? (Maybe it is just attempting to hold the Dmax back that does it... ):h )

The red hot pads held against a red hot rotor while the rest of the rotor cools down tends to leave hard spots in the rotor. Thus the need to creep and evenly cool the rotors after a hard stop.

This creep may help some people ruin less rotors. And after a hard spot is in a rotor it is junk as the turning tool just bounces off the hard spot leading to pedal pulse within 3K miles of a brake job.
 
Also buying quality rotors you get what you pay for. I love ceramic pads, last forever, no rusting dust.

I have heard of people getting stuff cryo'd. (sub frozen) supposed to really strengthen metal bringing it to -100 or -200 or some stupidly cold degree.
 
The cyro treated rotors are available at rockauto. I haven't looked at drums yet. All the military drums and rotors are cyro treated. A company in minnesota developed the process. It is supposed to more than double rotor/drum life. The cyro treated rotors were less than $20 more than the non-cyro slotted rotors for a k2500hd.
 
FWIW, I live way out gravel/dirt road from hiway and 30 miles of mountain roads to get to town. Also haul water, 500 gal bed tank, on same back roads. Getting my sig truck ready as a B/U to an old Ford that's real tired.

Driving empty--once around shudder from front and nose dive, rear wheel hop and skitter on the dirt washboards, ABS in and out. Driving loaded-- RF lockup first, then LF, then rear ABS kicked in. So, brake inspection, Log says 37k on brakes. LF uneven, inside pad almost gone, RF even as were both rear.

Front-found LF rotor warped and inside glazed, replaced--RF rotor ok but worn, replaced--new raybestos semi metallic pads. Test drive loaded, both fronts locked up before ABS and nosedive worse.

Rear-drums good, near new, replaced shoes with raybestos semi-metallic. Test drive loaded---no difference. Took rears apart again, looked at wheel cylinders--they were 1".

Upgrade--I found that the 1 ton 454 shows 1 3/16" wheel cylinders, measured center to mount flange--same. Replaced both wheel cylinders. Test drive loaded, no real nosedive, ABS kicks in just as fronts slide on dirt or asphault. On asphault about the same. Test drive empty, half fuel, much less nosedive, less rear skitter, ABS kicks in first on dirt---on asphault ABS kicks in just before front locks up. Much less pedal force needed.
 
millsroger said:
FWIW, I live way out gravel/dirt road from hiway and 30 miles of mountain roads to get to town. Also haul water, 500 gal bed tank, on same back roads. Getting my sig truck ready as a B/U to an old Ford that's real tired.

Driving empty--once around shudder from front and nose dive, rear wheel hop and skitter on the dirt washboards, ABS in and out. Driving loaded-- RF lockup first, then LF, then rear ABS kicked in. So, brake inspection, Log says 37k on brakes. LF uneven, inside pad almost gone, RF even as were both rear.

Front-found LF rotor warped and inside glazed, replaced--RF rotor ok but worn, replaced--new raybestos semi metallic pads. Test drive loaded, both fronts locked up before ABS and nosedive worse.

Rear-drums good, near new, replaced shoes with raybestos semi-metallic. Test drive loaded---no difference. Took rears apart again, looked at wheel cylinders--they were 1".

Upgrade--I found that the 1 ton 454 shows 1 3/16" wheel cylinders, measured center to mount flange--same. Replaced both wheel cylinders. Test drive loaded, no real nosedive, ABS kicks in just as fronts slide on dirt or asphault. On asphault about the same. Test drive empty, half fuel, much less nosedive, less rear skitter, ABS kicks in first on dirt---on asphault ABS kicks in just before front locks up. Much less pedal force needed.
Click to expand...

Good info, I thought the 1 1/16" were the big ones. Wish I would have known this 6 months when I redid my rears, would have stepped up to the bigger wheel cylinders(may still as they aren't that expensive, and I still get some break leading under hard braking even with the updated shoes).
 
Getting back to the subject proportioning valve--if working properly, they are kind of load sensitive in reverse, light load needs less pressure so they don't back off the rear, heavy load--pressure goes up and then they back off the rear. Think about that for a bit----totally backwards!!!!!

What it should do is back off the rear under light loads when you don't need as much rear brake.

The burb is much heavier in the rear compared to an empty PU and they changed the pressure point to compensate.

IMHO---should be removed altogether!!
 
OK, I've got some good ideas from reading this thread and a couple others here. But here's what brought me in the first place...

I notice with my '99 that if I'm in traffic and suddenly everyone stops I can push the pedal so far I feel my foot rubbing on the front wheel!(which helps with the braking a little I guess) In fact, a couple times I started to take a different lane as to avoid a rear-ender! But if I let up and stab it again, it stops pretty good. Granted, I've scrubbed some speed at that point, but I'm wondering why it needs 'pumped' to stop like it should. Anybody with similar experience?

I'm thinking I'll try fresh fluid/bleeding along with adjusting the rear. But with so many miles, I wonder if the PS pump/master cyl/hydroboost might be suspect. The pads looked about 40% when I put the new wheels on.
 
restoguy said:
OK, I've got some good ideas from reading this thread and a couple others here. But here's what brought me in the first place...

I notice with my '99 that if I'm in traffic and suddenly everyone stops I can push the pedal so far I feel my foot rubbing on the front wheel!(which helps with the braking a little I guess) In fact, a couple times I started to take a different lane as to avoid a rear-ender! But if I let up and stab it again, it stops pretty good. Granted, I've scrubbed some speed at that point, but I'm wondering why it needs 'pumped' to stop like it should. Anybody with similar experience?

I'm thinking I'll try fresh fluid/bleeding along with adjusting the rear. But with so many miles, I wonder if the PS pump/master cyl/hydroboost might be suspect. The pads looked about 40% when I put the new wheels on.
Click to expand...

Sounds like your rear brakes are way loose. Have you tried adjusting up the rear brakes manually to see if it tightens them up?
 
I actually haven't tried anything yet. I just noticed the problem in the last couple days. It stops OK accept in a panic situation. 3 times since friday I thought I was about to cause my first accident and it's got me wondering... Traffic was heavier than usual this weekend because of a festival. And something about people on vacation, they leave their brain at home and forget how to drive, among other things.(not that they ever really knew how in the first place, it just gets much worse...)

But I'm wondering about the power steering pump because I've noticed that when I spin it to lock real quick, it gets real hard, like I don't have enough assist or something. I notice it going right more than left, and it was worse before I put the wheels/tires on. IDK?
 
Can you turn the fronts when stopped at idle?? If so, pump pressure is up.

ABS, if you also feel shudder when hard braking then the ABS is kicking in and it don't get any better.

Auto adjusters--when working--do not adjust in fine increments so doing a manual check will probably always result in several 'clicks' before slight drag is felt---if that's what you find then the adjusters are actually working.

Pedal going that far down is usually air somewhere. Even with not so good brakes the pedal only goes down a couple of inches before it gets hard. You can check for a stuck proportioning valve by just opening a rear bleed and waiting, it should dribble fluid fairly rapidly--not a stream, just good dribble. Both sides should be even.

From the ABS out, the lines are bled normally by the two person open-press-close-release method. I do not know the procedure for bleeding the ABS up to the master cylinder. I hear it will take alot of fluid.

BTW, bleeding the ABS should go first because if there is air you will simply pump it down the lines toward the wheels.
 
Here's something you need to try.

When setting still and with motor running, put light pressure on the brake pedal. Try varying amounts of light pressure. Does the pedal at any time feel like it is slowly going down towards the floor under light pressure? If so, then apply quick hard pressure, like a panic stop. Does it hold good when you do this?

Now, find a road with no traffic on it and do the same thing while moving at about 20 to 40 MPH. Under very light pedal pressure does the pedal feel like it is going slowly towards the floor? If so, then apply quick hard pressure like a panic stop. Does it hold good when you do this?

If at any time, while under light pedal pressure, the pedal slowly sinks down towards the floor, and then holds when sudden hard pressure is applied, suspect a master cylinder to be going bad.

Try his and report back with results.

Don
 
Well adjusting the rears made a world of difference. It's still not the 'screeching halt' kind of braking a guy would hope for, but these trucks aren't known for that anyway. Much less pedal travel to get stopped now. I didn't flush or bleed, I just adjusted because I was running short on time. I do think my PSP is getting weak and I have warped front rotors (the last guy did it not me). So I'm not short of stuff to do to this thing along with all the 'fun parts' that keep showing up at my door!
 
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