Trailer brake problem-air over hydraulic discs
 

On my Performax trailer it has air over hydraulic Kodiac disc brakes. 4 times now the outer pad has somehow left the caliper. Twice on 1 wheel and now two others. Then the piston pulls the caliper over against the rotor and kills the rotor and caliper. Plus the piston gets extended far enough out to where it leaks fluid and soon the master cylinder is emptied and no brakes.
One thought was the piston was retracting too far and too much clearance causing a lot of slop and possible vibration. I installed a 2lb residual valve and it didn't happen for probably about 10,000 miles this year. But happened again today.

Calipers slide really easy back and forth. I didn't notice any excessive run out over the winter. Didn't measure, but wasn't obvious.

Any thoughts or ideas?

Re: Trailer brake problem-air over hydraulic discs
 

I also have the Kodiak disc brakes on my triple axle trailer. My trailer uses the electric over hydraulic pump to apply brakes. I have installed disc brakes on a lot of trailer and have found this type of failure is caused by plumbing the brake lines directly to the calpier with no brake hose as kodiak recomends on all sprung axle installs. The caliper does not slid when in use and wears outer pad very quickly. when replacing pads you should be bending tabs over on pads to insure they stay in the caliper. I would recomend calling Kodiak and speaking with their tech guy, he is very helpfull. I have also found that the calipers and pads are available form any Napa store, the only part not available is the rotor. the rotor is a Kodiak only part. even with this problem I would never go back to electric drum brakes. I hope this is of some help.

Re: Trailer brake problem-air over hydraulic discs
 

Thanks for the reply. It's plumbed with hard lines to brackets on the frame, then rubber flexible lines to the calipers, and braided steels flex hoses on a couple that broke (free replacement from Performax, thanks Ronnie!)

The outer pads don't have any tabs (at least on the ones I've found at a very good brake supplier near me) and the little pins on the back of the tabs to locate in the caliper are pretty short. I've used a lot of the spray adhesive too.

I'll try calling. Did once before but must have got the wrong guy....

Re: Trailer brake problem-air over hydraulic discs
 

Sorry I could not have been of more help. There must be something that is not allowing the caliper to slide and causing outside pad to wear quickly. You mentioned broken brake hoses, are you sure hoses are long enough and not stretching to far when axle moves up and down? what is weight capacity on axles, how many lugs per wheel?

Re: Trailer brake problem-air over hydraulic discs
 

Re-reading my original post, I guess I wasn't real clear about what's going on. It's not so much of a problem with the outer pad wearing quickly, it's completely missing! Or is that what happens when the caliper doesn't move? When I removed the caliper it slid very easily on the bolts and bushings.

The hoses do seem to be long enough. Have a little play in them and not being stretched.

It's a 3 car, 36' stacker. 3 8000lb 8 lug axles. It's close on weight. Have 23,400 on the axles.

Thanks again for your help!

Re: Trailer brake problem-air over hydraulic discs
 

When the caliper doesn't slide the outside pad wears quickly, this is the only way I could see the pad coming out of caliper. I have seen a failure when the bonded brake material has come off the steel backer and pad has come out. I have gone to all riveted pads on my trailer for that reason. Napa should have riveted pads (pads from a 1985 Cadillac Deville along with calpier are the same as Kodiak parts). Check the wear on the inside and outside pads to be sure they are wearing the same or close. when I service this style brake I pull rubbers and sliders and make sure they are clean and no debri. make sure to use disc break slide grease on all slider bolts.

Re: Trailer brake problem-air over hydraulic discs
 

Great, thanks. I did maintenance on the brakes over the winter and did as you suggested with the grease and tried to be really clean and make sure it operated correctly. I'll check the rest of them to see if they're wearing equally. Just a bummer I can't do any diagnosing on the one that's screwed up. Makes perfect sense what you're saying. Frustrating and expensive to fix when you think you've done it right the first time :(

But I'll definitely double check all the hose lengths as well.