Brakes SuperCub Restrictor valve.

Hi there,

I am the new owner of a Certified PA18-150 180hp, with ABI callipers, I believe an STC for a bigger piston and ABI dual piston callipers. Currently running 26 inch Goodyears and soon to run 31 ABW.

The brakes have a lot of travel in the pedal, but work well enough. I was told that the brakes had been "wound back" or restricted somehow so that they were not too aggressive. How does that work, short of leaving air in the lines?

Also, the brake lines are running out of the bottom of the callipers, making it easier for a stick to catch them. Is that standard?

Thanks
Damien

I think those are just the stock master cylinders... Going to need Steve's / Dakota or Airframes (old NorthRiver) with the bigger tires.

yep - thats what I see....

Pop that plug and top the brake reservoir off with 5606 hydraulic fluid. Reinstall the cap, pump the brakes and repeat til. The pedal is firm and the fluid level doesn't go down anymore.

The brake housings can be reversed. Top threads are the same as bottom threads. Just put an ABI housing on my 185 and the bleeder was put on the bottom, hydraulic lines on top. No sense hooking brush or other things.
Never saw a restrictor valve on a cub hydraulic line. Pedal travel is like Steve says above. Cub brakes are as simple as you can get.

I would agree flip the calipers so the brake line is on the top. Change out that 90 degree AN fitting for a 45 degree and try to keep a constant uphill run to the line all the way to the fuselage. Do a google search and you will see some pics. So why was the caliper mounted with the line in the bottom to begin with??? I think it is because most all early planes had covered gear legs, running the line out the bottom of the leg was easy, so when they changed from the old drum brakes to disks they just kept the lines that way. Many things are done with no thought process other than that is the way I saw my buddy/teacher/dad do it.

DENNY

Looks like you also have parking brake valves but the arm has been removed. You might install a new arm so you can use them or if you don't like parking brakes remove the valves completely.

Bear in mind that if you install brake boosters of any type (steves, airframes) the hose gets moved farther forward and will necessitate re-routing your hose in front of the tube that it sits over or coming up with some other creative routing. Your existing routing with the hosing going over the back of the fuselage tube probably won't work.

For what it's worth I've never had a problem bleeding my brakes with the line going in the bottom of the brake caliper. It's just what you do if you have old covered gear legs.