AirSpeed VW Community Forums

General Forums => Air Speed Lounge => Topic started by: beetlemandan on September 21, 2014, 08:18:17 AM

Title: master cylinder grief
Post by: beetlemandan on September 21, 2014, 08:18:17 AM
so I purchased this master cylinder for my 68 Baja:
http://www.cip1.ca/ProductDetails.asp?ProductCode=VWC%2D113%2D611%2D015%2DBD

except mine is an FTE ( made in Germany) brand, same part number.

problem is, the residual pressure check valves from the original master cylinder will not fit in the new one. I thought that the new m.c. might have internal ones ( like some superbeetles had) so I hooked it up. but it does not, and the pedal is non existent till I pump it a few times.

I see that cip does not carry any residual pressure valves. I can get some from lordco that keep 10 psi in the lines, but it seems like a Band-Aid for a problem that shouldn't be.

has anyone had this problem? or did I just get a defective part?
Title: Re: master cylinder grief
Post by: Lanny on September 21, 2014, 11:28:14 AM
Do you have drum or disc brakes? Drums shouldn't need any modifications at the master. I suspect air is in the system.
Title: Re: master cylinder grief
Post by: beetlemandan on September 21, 2014, 12:01:47 PM
I have drums on all 4 corners. the residual pressure valves prevent the drums springs from forcing all the pressure back into the master cylinder and reservoir. at least that's what I've read on the samba so far

Title: Re: master cylinder grief
Post by: mitchy965 on September 21, 2014, 05:27:13 PM
i also suspect air or poorly adjusted shoes,try clamping off the flex hoses after a good bleed starting from the furthest cylinder from the master.if the pedal comes up remove 1 clamp at a time until the problem returns and check that wheel for adjust or cly problem
Title: Re: master cylinder grief
Post by: purple turd on September 21, 2014, 06:40:00 PM
Or vacuum pump on the rt rear cylinder. Suck the fluid all the way through. May give a better pedal for final bleeding
Title: Re: master cylinder grief
Post by: beetlemandan on September 21, 2014, 07:30:51 PM
 I got someone more experienced at pumping the brake pedal, and lo and behold, I've got pedal now!

I also consulted a later factory manual and as of '73, the master cylinders no longer require residual pressure valves, due to an update in manufacturing.

problem solved!