[mcdblj]

I am currently installing my rudder pedal/breaks. I am aware of the offset mounts to the firewall. I am having a issue with clearance in the wells. I find the break cylinders to be hitting the side wells and very little clearance. Anyone else experience this issue?

Cheers

 

[smokyray]

Pedal Pusher...

I am currently installing my rudder pedal/breaks. I am aware of the offset mounts to the firewall. I am having a issue with clearance in the wells. I find the break cylinders to be hitting the side wells and very little clearance. Anyone else experience this issue?

Cheers

Hey Jay,
Age old problem.
One fix is to first make sure the master cylinder is plunger up, not down. This also helps in brake bleeding. Next, make sure the bolt head for the cylinder attachment is toward the side and the nut is away. Washers here and there helped mine clear. The best fix on mine was simply using washer spacers and a bit of bending on the mount bracket. They're still close and every 4 I inspect has similar challenges. Good luck...
V/R
Smokey

 

[vfrazier]

Jay,

On some of the OLD kits, and I suppose, depending on which master cylinder you have, it was necessary to cut, file, or grind away part of the mounting tab. Maybe even redrill the mounting hole if I recall from way, way back.

If you're not sure, post a photo for the VAFers to look at. Someone will know just what to do!

 

[Les Boatright]

RV-4 Brake Cylinders

Hi Jay,
OH YES, I too had issues with my brake master cylinders interfering with the keel-ribs, or tunnel walls. It's pretty tight in there, and the RV-4 pedals do not hinge straight backward & forward like most RVs, they're mounted on an angle to clear that angled keel/tunnel wall. It's one of those typical homebuilder situations where you just have to find a way to make it work out.

In MY plans set from circa 1996, drawing 37 depicts the master cylinder oriented down, and the piston, or plunger & spring, pointing UP like Smokey said. BUT there's a note on the drawing which points you to DWG 42 "FOR MORE DETAIL". DWG 42 has a figure which shows the cylinder installed inverted, so the plans aren't even consistent. I did some research and found photos of RV-4s that were built both ways, plunger up & plunger down. For my case, there was just no way to install the cylinder down without having the body of the cylinder interfere with the tunnel wall, so mine are installed inverted. I know that makes bleeding the brakes a little more difficult, but the only other option I saw was to modify the gusset on the pedal or grind away something that I didn't want to grind. Some trial and error using washers as spacers also helps. Also, keep the rudder pedal castle-nuts on the outboard side of the pedal, away from your foot, so that the cotter pin won't hang up on your shoe and work loose.

There's a way to make it work, it's just typical problem solving, which is part of the Fun and Frustration of building a -4. Is "Funstration" a word?

Best of Luck on your project!