I've been on a caliper-rebuilding kick for awhile. Decided to pull the calipers apart on my '97 K2500 8,600lb (8-lug) because the fluid in the reservoir looked horrible.
Turns out, the front pads are hardly worn, and the calipers are both black-painted remans. Neither had sticking pistons, but there was plenty of sludgy crap inside. I bought the truck 2 1/2 years ago, the previous owner neglected all sorts of problems. Apparently, they threw on rebuilt calipers and fresh pads, but didn't bother to flush the brake fluid.
Left side was no real problem. Bleeder screw needed some Oxy-Acetylene encouragement, but the piston popped right out with some compressed air, and cleaned-up nicely. The slider pins and bolts moved freely. The dust boot is not easily removable without wrecking it, so I left it in place. Removed the square-cut seal and wiped it clean. I cleaned up the piston and the caliper bore with clean rags and aerosol brake cleaner. Went back together, and back on the vehicle. I even re-used the copper washers on the brake hose banjo bolt. Bleeder screw threads lightly painted with anti seize.
The right side caliper was a bugger. Somebody installed a bleeder-screw "repair kit". Of course the repair kit has a microscopic bleeder screw (5/16 wrench size instead of 10mm) which was totally seized. I broke it off. I blew the caliper piston out with compressed air as usual, cleaned up the piston and the caliper bore and seals. Then I tried drilling out the bleeder screw with a left-hand drill bit, which I hoped would back-out the screw. Nope. But that did leave me a hole in the bleeder screw to pound an Easy-Out removal tool into. Again, with some Oxy-Acetylene action warming the iron around the bleeder, I got the whole repair kit to back out. This left me with a perfectly-usable caliper minus a working bleeder screw.
NAPA lists three bleeder screw repair kits, but none of the on-line photos look like the one I removed.
UP-BF17,
UP-BF117, and
NOE-6755180
NAPA can't be bothered to list the sizes or thread pitches for any of these on their consumer web site, and that info isn't on the in-store computer either. And the local store didn't stock any of them, so I couldn't test-fit. It kinda bugs me that I managed to clean up the caliper piston, extract the broken bleeder, but can't figure out what bleeder repair kit to use.
I came home with another black-coated "Total Eclipse" reman caliper; p/n CAL-SE4848, about $40 plus more than that as a core-charge. I'll return the core later.
It'll be awhile before I get the replacement caliper bolted-on, and the fluid flushed.
Photo 1. Contaminated piston from sludge inside caliper. The black spot near the piston is a couple drops of contaminated brake fluid!
Photo 2. Cheap, low-grade caliper mounting hardware. The OEM stuff does not allow the bolts to be removed from the sleeves, and the chrome plating is better--more rust-resistant.
Photo 3. Broken bleeder screw. The rusty "circle" around the freshly-broken bottom part of the bleeder is the top of the outer section of the "repair kit".
More photos coming...soon (?)
Turns out, the front pads are hardly worn, and the calipers are both black-painted remans. Neither had sticking pistons, but there was plenty of sludgy crap inside. I bought the truck 2 1/2 years ago, the previous owner neglected all sorts of problems. Apparently, they threw on rebuilt calipers and fresh pads, but didn't bother to flush the brake fluid.
Left side was no real problem. Bleeder screw needed some Oxy-Acetylene encouragement, but the piston popped right out with some compressed air, and cleaned-up nicely. The slider pins and bolts moved freely. The dust boot is not easily removable without wrecking it, so I left it in place. Removed the square-cut seal and wiped it clean. I cleaned up the piston and the caliper bore with clean rags and aerosol brake cleaner. Went back together, and back on the vehicle. I even re-used the copper washers on the brake hose banjo bolt. Bleeder screw threads lightly painted with anti seize.
The right side caliper was a bugger. Somebody installed a bleeder-screw "repair kit". Of course the repair kit has a microscopic bleeder screw (5/16 wrench size instead of 10mm) which was totally seized. I broke it off. I blew the caliper piston out with compressed air as usual, cleaned up the piston and the caliper bore and seals. Then I tried drilling out the bleeder screw with a left-hand drill bit, which I hoped would back-out the screw. Nope. But that did leave me a hole in the bleeder screw to pound an Easy-Out removal tool into. Again, with some Oxy-Acetylene action warming the iron around the bleeder, I got the whole repair kit to back out. This left me with a perfectly-usable caliper minus a working bleeder screw.
NAPA lists three bleeder screw repair kits, but none of the on-line photos look like the one I removed.
UP-BF17,
UP-BF117, and
NOE-6755180
NAPA can't be bothered to list the sizes or thread pitches for any of these on their consumer web site, and that info isn't on the in-store computer either. And the local store didn't stock any of them, so I couldn't test-fit. It kinda bugs me that I managed to clean up the caliper piston, extract the broken bleeder, but can't figure out what bleeder repair kit to use.
I came home with another black-coated "Total Eclipse" reman caliper; p/n CAL-SE4848, about $40 plus more than that as a core-charge. I'll return the core later.
It'll be awhile before I get the replacement caliper bolted-on, and the fluid flushed.
Photo 1. Contaminated piston from sludge inside caliper. The black spot near the piston is a couple drops of contaminated brake fluid!
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Photo 2. Cheap, low-grade caliper mounting hardware. The OEM stuff does not allow the bolts to be removed from the sleeves, and the chrome plating is better--more rust-resistant.
You must be registered for see images attach
Photo 3. Broken bleeder screw. The rusty "circle" around the freshly-broken bottom part of the bleeder is the top of the outer section of the "repair kit".
You must be registered for see images attach
More photos coming...soon (?)
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