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ATE Master Cylinder

jbarneshb

New member
After rebuilding my ATE wheel cylinders and replacing my front brake pads I tried bleediing them both with a vacuum pump and by hand. I can't get them to pump up right. I notice that when I squeeze the front brake handlle I get some fluid back into the reservoir. If I hold my finger over the hole in the reservoir and squeeze the front brake handle I can feel pressure. Have I not bled the master cylinder right or do I need to rebuild it? Also do the two hoses that come off the master cylinder swivel anywhere or do they need to be disconnected from the forks and spun around to diconnect them? Thanks
 
If they will pump up any pressure at all, loosen the bangjo bolt at the master cylinder while keeping pressure on the lever. If there is air present you'll see the bubbles. Repeat a couple of times until the lever holds pressure.

Sometimes what happens is that you can end up with air in the master cylinder that you can't get to go down to the bleed screws.
 
I deciced to rebuild the master cylinder but it looked ok so I think it probably did have some trapped air. It doesn't have banjo bolts rather the hoses themselves screw into the master cylinder. When I get it back together I'll try and unscrew the hoses enough to let it bleed past the threads.
 
Consider this, I did a rebuild on an ATE master cylinder that had been sleeved. I had to bench bleed the thing before I could get it to build sufficient pressure to fully bleed the system. This was on a single disc front end on a /7.
 
Well I put the rebuild kit in, bled it again and it works good. Master cylinder worked fine before I rebuilt wheel cylinders and replaced brake pads so it seems funny that it would go bad but it works now and that's what counts.
 
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