Trouble bleeding brakes.

How much vacuum are you applying to the system when bleeding it? Too much can actually collapse the wheel cylinder cups and suck air into the system. With a vacuum system you shouldn't need to hold the pin (which is all the special tool does, hold it from moving) manual bleeding, ie pump it up, hold, release etc, yes you need the tool to hold the pin from moving. A pressure bleeder shouldn't need the tool unless someone is using high pressure (10 psi is more than enough).

Why are you bleeding the brakes? what was replaced that required this?

Whitelightning

"Whitelightning" wrote in news:_L1Ig.2181$p23.616@trnddc04:

Thanks Lighting!

I'm only using a little hand pump vacume tester... about 10 - 20 psi max. I replaced the master cylinder because sometimes I have to pump twice to get good breaking. I think I'll just take it to a real mechanic next week. This job really needs an experianced expert.

Thanks again! Dan

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Did you bench bleed the master before you installed it? And if so how did you do it?

Whitelightning