Technical Mustang Master Cylinder Squirting

Here's a video I shot yesterday. The squirt happens as I press on the pedal especially if it's not really slow

 

Not sure if these photos are helpful? I can't remember what pedal position I was at in those ones.

 

All master cylinders squirt out the ports in the reservoir, theres nothing you can do about it short of running a master cylinder with a remote reservoir. As the fluid starts to pressurize it's going to the path of least resistance, which is the ports above the cylinder, until the piston cups pass by and block them off. You can't block them off permanently because then the fluid wouldn't be able to drop as the brakes wear over time. Since you're having such difficulty I would consider taking the car in to a pro, especially when dealing with brakes, it's a matter of life and death.

 

Thanks, the pedal feels fine, it was leaking from the lid but I made it seal, otherwise I don't see any issues with the particular set up. I thought two residuals could make it squirt but they are in line so in theory 1 vs 2 shouldn't matter. There are two residuals because the rear likely has one built in to the M/C and I put an additional one since I wasn't sure.

As of now I'm thinking I can leave the M/C alone.

 

I do not see the fluid near the top of the reservoir!!! How do you expect it to stop squirting up to the lid?? Man, you are hard-headed.

 

keep the reservoir full at all times.

 

The previous photos might be deceiving since the car is not perfectly level since my rear jackstands are a tad bit lower than the fronts. This makes the fluid look lower than it is from reflections. The fluid was at 3/4. I now filled to the top given the inclination of the vehicle. Below is a photo.

The squirt is still there!

 

It will always be there. It just won't shoot up like a geyser. Let's see a video of it now.

 

It shot up like a geyser again pretty much same height. I put the lid back on that's that.. It's not leaking outside of the gasket anymore after doubling up with cork.

I'd shoot another video but I cleaned it all up really well so I can constantly check for leaks to make sure it is indeed fully leak proof at the lid.

 

That just doesn't seem right. You shouldn't have to back-up the master cylinder cap with anything.

 

Yea. I have read some other forums online of people having had a similar issue with an early Ford M/C. Some tried doubling up the gasket and it solved their problem, others modified the spring to tighten the lid better.

 

I have never ever looked into a master to see what it was doing.. especially with the cover off, unless I was bench bleeding it. Slap the cover on, drive it and study its habits.

 

Will do thanks!

 

I'm bad at completely closing out an issue even if it was solved. I remember this thread and I had a Dorman Mustang M/C I had bought online.

I'm looking at my excel file with notes/part numbers and I had returned the dorman one and went to NAPA and bought a 69' Mustang M/C and the lid clip was so much harder to move. It took a bigger screw driver. Never saw a leak again from the lid.

I had a bunch of other brake related forums up but I have gotten all the kinks worked out, no trapped air, no funny pedal that takes two pumps, and the front pads have worn in and it feels pretty good with the big brake kit I'm running.