Thursday, January 17, 2013

BRAKES!

Got to spend some time in the garage the other night, one of the problems with the '79 Polaris Cobra is the lack of brakes. The brake caliper on this system has 2 pads, one the caliper pushes against another which stays still in the caliper. Polaris has long used hydraulic brakes and in this case the driven pad is hydraulically actuated and on my sled that pad was stuck.

I found that using a big screwdriver I could pry the pad back away from the disc but when I applied the brake and the pad moved back in it would be stuck against the disc again. I pried and applied and pried and applied and while it seemed like it was getting a little better I wasn't gaining much.

Realistically I knew I needed to pull the caliper and properly clean everything. Unfortunately on this sled the brake caliper is attached to the chaincase inboard of the driven clutch. The driven clutch has to come off for this to happen and the chaincase has to come apart for that. I got as far as opening the chain case and pulling the chain and top sprocket before I gave up. Fortunately with the top sprocket removed the driven clutch can turn since you're not trying to push the track which helped with freeing the pad.

Finally in desperation I carefully squirted a little PB Blaster around the edge of the pad, now when I worked it back and forth I could feel it getting looser and eventually I could apply the brake and it would release easily. With that accomplished I sprayed some brake cleaner on the pad and disc so the PB Blaster wouldn't grease the brakes and everything seems good.

Its a good feeling to make progress.

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