Here we go. My first post. Had to put on new drivebelt(05 1200 custom sportster). When replacing rear caliper I manuallypushed plunger back in and long story short can't get rear brakes to work. Have tried bleeding manually at first and then got a Mity vac. Got fluid without air bubbles but still no brakes. HELP
rear brakes
- Thread starter dozerman
- Start date
Possible you forced air that was in the caliper back up into the system. More bleeding may do the trick here. Check to see if you get any pressure release when you break open the bleeder screw with the brake lever depresses after a few pumps. If not you may have a master cylinder problem then. You do have brake fluid in the MC ? Right?
Got fluid in mc reservoir. As matter of fact I vac-pumped a whole reservoir full thru the pump. So nothing but new dot 5 in there now. No pressure release when cracking open the bleeder either. Didn't expect any though cause brake pedal goes all way down without any resistance. Guess will have to rebuild mc huh?
I had a similar issue with front brakes before, it turned out that pushing the brake piston in further than it usually travells also pushed the master cylinder through its bore further than it usually travells and this made the rubber seal come into contact with a rough spot in the bore that destroyed the seal. Bought a master cylinder rebuild kit, polished the bore with very fine wet & dry to ensure it didnt hit the same rough spot and I was back in business.
Just re-read that and it wasnt too clear. I meant to say it pushed the master cylinder piston through its bore further than it usually travels. It did involve 2 days of repeateadly stripping and bleeding the system and a real HERES JOHNNY moment before I figured what had happened. It wont be obvious if you take the piston out, you'll only know for sure when you fit a new piston.
Hope it goes better for you than it did for me.
Just re-read that and it wasnt too clear. I meant to say it pushed the master cylinder piston through its bore further than it usually travels. It did involve 2 days of repeateadly stripping and bleeding the system and a real HERES JOHNNY moment before I figured what had happened. It wont be obvious if you take the piston out, you'll only know for sure when you fit a new piston.
Hope it goes better for you than it did for me.
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