How full should master be?

[jake]

Brake fluid is leaking from the front of my master cylinder, the seal is brand new along with the master. Is it too full? Should the seal have the rubber rings up or down?

 

[1978 NYB]

Like the last picture. Is it leaking out of the top of the master cylinder where the cap seals?

 

[polara71]

I keep mine like the bottom photo. With brakes being hydraulics and the calipers and cylinder reaching out with wear on the brakes it leaves more room within the lines for fluid and lowering the reservoir. With that the rings get pulled down into the cylinder as the fluid level gets lower................ thats all I think I know

 

[jake]

Yes, it is leaking out the top where the cap seals, and I had my seal like the bottom picture.

 

[1978 NYB]

The last picture is absolutely correct. Is the cap bent and not sealing properly??

 

[1970cat]

looks like a rebuilt master, is the bale wire tight enough? should take considerable prying force to move it to the side.
also, if there is a vent hole, make sure that it is clear

 

[jake]

I had my front brakes dragging alittle, so I adjusted the master push rod about .5 inch shorter and that is when it is happening. Tomorrow I going to lengthen it about .25 of an inch and see what happens, dont know if that has anything to do with it. The cap looks flat and straight, I ll see tommorrow. Thanks for the help.

 

[jake]

Well, I got around to adjust my pushrod and brakes are working great, still leaking like a facuet. Turned the rubber seal upside down, like the middle picture and it seals no problem, and brakes work great! Dont get it, but not fixing what works.