Master Cylinder Issues .... again

[lee]

Last winter or this spring I replaced one of my Girling master cylinders with a new Wilwood one. This was for the front brakes. Last night in one of my last steps getting ready for the weekend I began bleeding the rear brakes since I'd swapped trannies. After a couple cycles of bleeding the first rear I had my front MC burp up a bunch fluid thru the top of the cap. From there on I could not get any significant pressure to the front brakes.

I pulled the front MC and took it apart finding some aluminum shavings in it. These didn't come from bore wear. I reasoned that since the car had been sitting with the tail up for so long that the shavings must have migrated down to the front of the MC and then caused the front little seal to not seal off. Sounded reasonable. Cleaned everything, reassembled and bled off the air but still can not get much pressure to the fronts.

My only guess is that the little front seal must have a tear or something in it. Have others had this happen?

My immediate need is finding a rebuild kit locally since I need to load the car up tomorrow night. The Wilwood rebuild kit part number is 260-3880 I think. Does anyone know of a road car that uses seals like this? I was thinking maybe some car might use the Girling as a clutch master. I'm guessing from what used parts I have that the Girling and Wilwood use the same seals and internals.

Any help would be appreciated.
Lee

[Martinracing98]

If you have a good parts place in town you may be able to take the seals in and get what you need by letting them know your bore size. I have done that when rebuilding brakes on my kart when I did not have time to get to a kart shop

[FV80]

Lee,
Not sure where you're headed, but you might check with Tim Lee at SafeQuip (SafeQuipRacingProducts.com). He carries a bunch of stuff and services MOST SEDIV races. He might have what you need and be THERE when you need it. .
Steve

[SR Racing]

Lee, I wish we had more time... I think it's to late to help now. The rebuild kits are $20.65 and the full master cylinder is only $47. So you might be better off getting a full master. BTW, That is the correct part number. (5/8 Rebuild kit)

Jim
SR

[lee]

Steve,
I'm going to VIR so Tim should be there as he usually is.

Jim,
I was the one who called you this morning about the 5/8 cylinder. Sorry I didn't get back to you but I left work to come try to work on this. I put a spare (slightly used) front seal in it and put it all back together and it now holds pressure. Nothing obviously bad looking about that little ring of rubber. Maybe it will be more apparent when I get a new seal to hold next to it. I've got a spare that has damage to the outer end of the bore but the internals I think are ok.

I swear, I bet it took almost a half a quart of fluid to finally get the rears firm. Does anyone use any kind of vacuum system to bleed brakes? If so, are they more effective at getting a good air free system?

Thanks,
Lee

[DanRemmers]

I have a hand-pumped power bleeder that I use on my street cars as well as my vee. I works very well and I don't need a second person. The only issue is the tight space in the nose of the vee to fit the adaptor that goes on the master cylinder.

[lee]

Dan, I'm not sure I follow. Is there an adapter that seals the top of the MC and then a suppose uses the vacuum to keep the reservoir topped off?

Showing my ignorance I guess.

Lee

[fv22]

Lee,
I use this one:
http://www.harborfreight.com/cpi/ctaf/d ... mber=92474
when I'm by myself. Works great, quick, easy and never had a soft pedal.
Good Luck,
Bob

[DanRemmers]

Dan, I'm not sure I follow. Is there an adapter that seals the top of the MC and then a suppose uses the vacuum to keep the reservoir topped off?

Showing my ignorance I guess.

Lee

Here is a link to what I have: http://www.eurosportacc.com/motive_powe ... e_line.htm.

It attaches to the MC (mine is a universal, but you can make your own adaptor with a spare cap). Add fluid to the tank, attach to the MC, then pressurize the tank. Bleed brakes and keep an eye on the pressure gage. The fluid in the tank replaces the fluid in the MC as it bleeds through the system.

[brian]

I've got a broom handle that I push on the pedal with and use a container with a clear line going to the wheel cylinder. Real high tech. If you have the rear backing plate rotated to "hide" the line behind the trailing arm, you will have to rotate the backing plate to put the wheel cylinder on top to speed up the bleeding process. Always do a preliminary adjustment on the shoes before bleeding.

[SR Racing]

We also have the self bleeders here. It's a one way valve that replace the normal valve. You just loosen it a bit and pump the pedal. The check valve prevents the air from coming back in. Seem to work fine.

Jim