I have a leaking problem in both my Blue Robart Valve. The first one when new holded pressure OK but after sitting unused for several months it started to leak. I thought I had a bad valve so I bought a new one and the same thing happened. :angry: After an hour or so there is not enough pressure to operate the gear.

I know the problem is in the valves because when I put them, installed in the airplane, inside a glass of water you can see bubbles escaping from it.

I have changed the O rings and lubed them with BVM O Lube to no avail.

Is there any way to fix this permanently, other than buying new valves each season?

I would appreciate any comments.

Eduardo

Eduardo, you probably have a bad o-ring in one of your retracts. It will allow air to go past the cylinder and you are seeing it come out of the exhaust port on the valve. Pinch off one retract unit at a time while the valve is under water to see which one makes it stop leaking. That will tell you which retract it is.

Good luck,

Mark

Mark

Good point, I hadn't thought of that. IŽll check it out and post the results.

Thanks a lot.

Eduardo

I've had problems with the blue one too. Wouldn't hold pressure above about 40 psi and down quick after that. Taking a suggestion I saw a long time ago, I took it apart and using rolled up 1000 grit sandpaper wet, I lightly scrubbed the inside of the valve. Was told sometimes theres a tiny burr from the drilling.

Next I found there was a ton of white grease in there. Got rid of most of that and reassembled. Works perfect now, but has a little more resistance to sliding. Frankly, I think there was so much grease the air was blowing by the o-rings.

I tested by looping short air hoses between the nipples on each end (up to up and down to down) and hooking up a tank and fill valve to the center connection. Threw all into water and observed leakage at 100 psi. Was none except a tiny amount during valve transit.

The other fellow is also right, on my old Rhom's in paricular, I had tons of leakage at the gear cylinders many times. The problem was the shafts sometimes get misaligned under rough use and need to be starightened. I've also had trouble with the plastic T's cracking or having blow by on the lines on the plastic T's.

Good luck.

Just as Mark said, one of the cilinders was leaking. I changed it and all works OK now.

Thanks again guys.

Eduardo