Haven't posted in a while, truck has become back up vehicle and doens't see the use it was. I finally, at 276,000 miles needed to replace my rear brakes. The shoes were shot and the drums didn't look much better. I put all new hardware on, new shoes, new hardware and new drums. All went together until I went to test drive it. Pedal went to floor before I was able to stop.

I have pulled the drums off and turned the ratchet attached to the parking brake lever. I bled the brakes with a pressure bleeder the week before and didn't not open up the system besided pulling the cap off to allow for expansion.

Any ideas? I've only done one or two drum brake jobs before so this was some what unknown territory for me and would love some suggestions.

Thanks,
Dave

Did you replace the rear wheel cylinder, too?

If you didn't, did you check the bleeder valve fer clogging? Just bled my 300k+ rear brakes and both valve were gunked up. Also, don't fergit the LSPV (load sensing proportional valve)...that's a common culprit fer gitting air in there. <img src="/forums/images/graemlins/wink.gif" alt="" />

Didn't replace the wheel cylinder. When I did the bleed all the valves allowed fluid out. Did the LSPV also. Drove to the shop with everything working fine, put on the new shoes and pedal goes to floor. I am sure it is the parking brake mechanism (not 100% or I would have this fixed <img src="/forums/images/graemlins/frown.gif" alt="" /> ) I jsut can't seem to figure out what it is about the parking brake mechanism I need to adjust / fix)

By parking brake mechanism, I'm guessing you mean the internal adjuster. When you put those back in, did you adjust them out so that the shoes just barely tick/drag the drums when you spin the wheel by hand?

Did you replace the spring cups? This shouldn't create the symptoms you're experiencing, but it was the only problem I had doing my rear drums - the retaining cups were so hammered that one let the pin through and released the shoe a couple hundred miles after I put it back together.

Nick a brake cylinder putting it back together?

Stretch a spring (hard to do but nothing's impossible).

Any extra parts?

The order of your response makes me wonder:


You didn't bleed it first then replace the shoes?

Regardless, first thing I'd probably do it bleed about a whole quart bottle of brake fluid through it, then start taking it apart again if a bleed doesn't cure it.

Could it be up at the master cylinder? You kept it topped up while you bled it, yes, didn't let it run dry?

Your answers to some of these might be exasperated "Noooooooo"s, but as I run through it in my head they're what come to mind as simple oversights that might cause this.

Two up on the MC. If you did fully bleed to all 4 corners with good spurts of juice - I mean good - spitting half way across the truck - then you have a MC that has decided to part ways with you. Stir up enough crud and all the parts can get messed with. Had the same problem with replacing front calipers. They bled good but stopping sucked. Replaced the MC and all is well.

FYI: the shoes must be adjusted to within about 2mms of the drum. This can only be done with the drum on.

Thanks for all the reply's. I haven't had a chance to do a decent test drive yet, only around the neighborhood, but it looks like a combination of adjusting the star wheel with the drum on (did so by pulling on the parking park arm that attaches the parking brake cable to back of the drum brake) and doing another brake bleed (I was using a power bleeder) and I believe I have fully restored the brakes. At least I REALLY hope so. I did get the smallest set of about 5 bubbles coming out of the passenger rear so that may have been it.

If problems remain I will probably look at the MC and then the LSPV (the LSPV is suspect as I have having rear end lockup issues, though I am hoping the new shoes and rotors may help there as they were really worn and not evenly).

Thanks again.

I noticed that the "self adjuster" that is driven by the parking brake will not catch if it is slack all the way to its mechanical limits. You have to start by turning it out a couple of turns.

That's what I was getting at. I'm not all that good making a ruler work in reality that way. A couple techs I trust told me the "by feel" way that I posted, and it worked well whenever I set drums up.

I've since gone discs and never looked back.

As I set under the truck last night I was so thinking discs. Will never rule it out, I would really like the full floating axle that comes with the disc conversion.

Just returned from a long gravel road and am happy to report the truck now stops with a firm pedal and the back end no longer is desperate to lock up. New shoes, hardware and drums plus some ample brake bleeding. And the help of 4x4wire!

Thanks,
Dave G