The Ford Barn

fftoddster · 02-28-2016, 04:09 PM

Master Cyl is new. Keeps leaking out the top cover.

Anybody else have this problem or am I just lucky?

Guess I can try to order a new master cyl lid gasket.

flatheadmurre · 02-28-2016, 04:24 PM

For dual...sheetmetal cover ?
Is the surface on the cylinder plane and smooth ?

fftoddster · 02-28-2016, 05:41 PM

Yes Mustang dual with metal cover held on by wire clip.

It's brand new, mounted to '39 type pedals under the floor with very limited hard access.

fftoddster · 02-28-2016, 11:53 PM

was just wondering if this was a common problem with how low the master cyl is mounted or if maybe just a bad seal on my cover.

fordor41 · 02-28-2016, 11:59 PM

Could be air in system. If so, the air gets compressed upon actuation of the brakes. Upon release the fluid is forced back to the M/C with such force, via the compressed ai,r that it can cause it to leak from the reservoir lid. Remove the top and press on the brake pedal and release normally. If fluid shots out the top, I'd bleed the brakes.

V8 Bob · 02-29-2016, 07:32 AM

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Quote:

Originally Posted by fftoddster

was just wondering if this was a common problem with how low the master cyl is mounted or if maybe just a bad seal on my cover.

That seal should be air tight, and not allow any fluid loss. Check to make sure the gasket is installed properly in the cover, and that the cover is placed correctly on the reservoir. Fluid level should be about 1/4" low.

john in illinois · 02-29-2016, 07:36 AM

The gasket has expansion chambers in it so return pressure should not make it leak. There must be something wrong with the gasket or the sealing surface. Is the cover on square and down tight. I know they are hard to see. Mirror and flashlight works good.

John

Bob beat me to it.

02-28-2016, 04:09 PM	#1
fftoddster Senior Member Join Date: Apr 2015 Posts: 158	Ford type dual master cyl leak Master Cyl is new. Keeps leaking out the top cover. Anybody else have this problem or am I just lucky? Guess I can try to order a new master cyl lid gasket.

02-28-2016, 04:24 PM	#2
flatheadmurre Senior Member Join Date: Apr 2015 Location: Sweden Posts: 3,045	Re: Ford type dual master cyl leak For dual...sheetmetal cover ? Is the surface on the cylinder plane and smooth ?

02-28-2016, 05:41 PM	#3
fftoddster Senior Member Join Date: Apr 2015 Posts: 158	Re: Ford type dual master cyl leak Yes Mustang dual with metal cover held on by wire clip. It's brand new, mounted to '39 type pedals under the floor with very limited hard access.

02-28-2016, 11:53 PM	#4
fftoddster Senior Member Join Date: Apr 2015 Posts: 158	Re: Ford type dual master cyl leak was just wondering if this was a common problem with how low the master cyl is mounted or if maybe just a bad seal on my cover.

02-28-2016, 11:59 PM	#5
fordor41 Senior Member Join Date: Oct 2011 Location: elmira,ny Posts: 1,517	Re: Ford type dual master cyl leak Could be air in system. If so, the air gets compressed upon actuation of the brakes. Upon release the fluid is forced back to the M/C with such force, via the compressed ai,r that it can cause it to leak from the reservoir lid. Remove the top and press on the brake pedal and release normally. If fluid shots out the top, I'd bleed the brakes.

02-29-2016, 07:36 AM	#7
john in illinois Senior Member Join Date: May 2010 Location: Illinois Posts: 2,184	Re: Ford type dual master cyl leak The gasket has expansion chambers in it so return pressure should not make it leak. There must be something wrong with the gasket or the sealing surface. Is the cover on square and down tight. I know they are hard to see. Mirror and flashlight works good. John Bob beat me to it.