HD465-7 Brake wear

[daterplant]

Unusual brake wear Komatsu HD465-7, we replaced the front brake pads and resealed the calipers including new pistons both sides, three weeks later the pads were worn out.
However, the outside pads were down to the metal, inner pads normal wear on the same calipers,(two calipers on each front wheel both had the same unusual wear)
We found the front brakes were coming on even when they were swiched off in the cab. The problem we think is low nitrogen pressure in the accumulators for the brakes, we set the correct pressures and put a guage on the caliper line to check the psi when the truck is working all seems ok now.

What we don't understand is why one side of the caliper would wear out the pads, with one pressure line into the caliper which would equal the pressure, six pistons in each caliper all free to move, disc and bearings good, no air in the system, no blockage in the calipers.

Anyone with a good explanation??

 

[oldseabee]

We had similar problem on Clark loaders years ago. Had air over hydraulic power clusters with residual pressure valves at the outlet which were supposed to keep the pads close to the disc for full brake application with little pedal stroke. Finally removed them because on some units the brakes would drag and wear out plus over heat the caliper. Not sure how your brakes are set up. Sounds like there is air trapped in the outside pistons and is holding the pads against the disc. Try a hand vacuum pump with a small hose on the bleed screws.