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Sun Aug 31, 2008 9:16 am

last night as we are heading to my Dad's to watch the Ducks whip the Huskies,we come out of the store roll up to the stop sign and the brakes go to the floor. I let off and pumped it a couple of times and it was fine.this has happened a few times now. any clues? air in the system? new master and clutch slave 6 months or so ago.

Sun Aug 31, 2008 11:18 am

just did it again on the way to the hardware store. could it be the booster or the pressure regulator? anyway to check these parts to see if they are the problem?

Sun Aug 31, 2008 11:24 am

If there is not fluid leaking out somewhere then unless there is some obvious broken part to the actual lever, the problem is the master cylinder.

Andrew

Sun Aug 31, 2008 11:39 am

no leaks. master cylinder is only 6 months old though.

Sun Aug 31, 2008 2:37 pm

I have gotten brand new, out of the box parts that were bad, and had to be returned. I think this happens a lot more than some of us may realize.

Sun Aug 31, 2008 3:58 pm

did a quick bleed of the brakes,the fluid that came out was pretty dark and nasty. should I start with a complete flush of the brake system and some new fluid? if it was the master, the clutch be acting up as well wouldn't it?

Sun Aug 31, 2008 4:15 pm

Bruce Wayne wrote: did a quick bleed of the brakes,the fluid that came out was pretty dark and nasty. should I start with a complete flush of the brake system and some new fluid? if it was the master, the clutch be acting up as well wouldn't it?

Hey Dude,

There are separate brake and clutch master cylinders. They share the same reservoir tank behind the dash. If you have a friend handy I would go under the van and have that person push on the brakes a few times. Inspect every single rubber brake line for signs of bulging. A bulging line is a failing line. I would definitely completely flush your brake fluid. It sounds old and contaminated.

Good luck,

Chester

Sun Aug 31, 2008 4:25 pm

Quote: There are separate brake and clutch master cylinders.

I know they share the same reservoir,but I thought they shared the same master too. mines a 85 GL

Sun Aug 31, 2008 6:26 pm

Bruce Wayne wrote: no leaks. master cylinder is only 6 months old though.

I have read that pushing the pedal all the way down to the floor when bleeding the brakes, might damage the internal seals causing it to fail.

Obviously the piston only travels about 1/2 down the cylinder so the above may only apply to older MC's with crap on the cylinder wall, but may apply to new too.

I found this tidbit out after doing it the wrong way. When I bleed my brakes, I don't push the pedal to the floor.

Cheers,

Neil.

Sun Aug 31, 2008 8:10 pm

should I use regular or synthetic brake fluid when I flush the system.

Mon Sep 01, 2008 5:36 am

Any brand name DOT 4 is fine, don't waste your money on synthetics. DOT 5 synthetic is a completely different fluid, and not necessarily superior.

Mon Sep 01, 2008 11:31 am

the master cylinder is shared by the clutch and brakes right? I have an 85 GL

Mon Sep 01, 2008 11:40 am

No, it's not. As mentioned previously, the brake and clutch master cylinders are two different parts.

Clutch master:

Brake Master:

The brake master cylinder has the reservoir pushed into rubber grommets at the top of it. The clutch master is below it with a hose from the reservoir down to it.

Andrew

Mon Sep 01, 2008 2:04 pm

is it pretty easy to replace? $100 from gowesty for a master.