jsharkey

Well Known Member
Earlier I had to re-bleed the RH brake on my RV6 and now it has gone soft again.

Has any one else experienced this? There are no obvious signs of fitting leaks. The plane hasn't flown yet but the calipers and master cylinders are a few years old by now.

I was about to do some more taxi tests but can't until I track this down.

Jim Sharkey
 
Brake bleeding

Are you pumping fluid in from the bottom of the brake puck, up to the reservoir? You need to do it that way in order to chase air bubbles up and out. Make sure the line from your hand pump to the puck nipple is full of fluid before attaching. You'll need to hook up an overflow tube at your reservoir top cap. When done back filling, snug down the nipple fitting, then try the brake peddle.
 
Earlier I had to re-bleed the RH brake on my RV6 and now it has gone soft again.

Has any one else experienced this? There are no obvious signs of fitting leaks. The plane hasn't flown yet but the calipers and master cylinders are a few years old by now.

I was about to do some more taxi tests but can't until I track this down.

Jim Sharkey

Could be the master cylinder.
To test, apply light pressure and see if the pedal slowly sinks. Applying heavy pressure should seal the cylinder cups and have no sink.