Master Cylinder Direction

[rpigeek]

I’ve been having a heck of a time getting my left brake pedal to not go soft. It has a Cleveland master. I’d like to reverse the master, but there’s not enough room to put the rod up. What have others done on their Harmon rockets?

 

[Ironflight]

Not a Harmon, but on the F1, I have Matco Masters, and the instruction say to put them on upside down for clearance. I could NOT get th,m to bleed that way, talked to George (at Matco) and was told that I might get lucky, but I realy should put them right side up. With careful bracketing and spacers, I got the clearance I needed, and they bled correctly the first time.

 

[Larco]

This is an older mod that Pat Hatch came up with regarding the RV-4, should be the same for your Harmon IIRC. Welcome to try it.

 

[HFS]

I’ve been having a heck of a time getting my left brake pedal to not go soft. It has a Cleveland master. I’d like to reverse the master, but there’s not enough room to put the rod up. What have others done on their Harmon rockets?

I recognized this problem from the beginning (build) and narrowed down the rudder pedals (just) enough to mount the old style Cleveland master cylinders "right side up" to solve that problem - doesn't take much but planning & execution ...

HFS
Harmon Rocket S/N 002

 

[rpigeek]

On this build it’s a lot harder after the fact. I can get it to bleed if I disconnect the lower bolt and swing it up so bottom side is higher and hold it with a zip tie. The question is if it’ll eventually capture any air in the line and get soft again. Only time will tell. If it does I’ll have to look at these ideas to modify the master or mounting. I really wish the mounting was on the outside where there is plenty of room.

 

[fixnflyguy]

As reference on my RV-4. I know on the -4, the pedals actually travel outward as they move AFT, following the tunnel profile slightly, due to the non-linear upper mounting points.

 

[131RB]

Remove the lower bolt and tip the master above horizontal. Tie it in that position with a piece of wire or equivalent. Bleed from the bottom up. It will bleed. Reverse the process when the air has been pushed out. Sometimes easier with 2 people.
Ryan