The short version. I have installed an air retract system in my P-51 (85"). I have just tried to charge it up for the first time. Not working for s---. The little Robart hand pump is worthless and complete crap for this size plane. I can't seem to get the system to charge. After I pump that little pump about 50 times it has only put about 5# of pressure in the system. As soon as I unhook it that little bit of pressure bleeds off.

Yes I was very careful on all fittings, but I am going to have to do the soapy water test. I think the problem is with the fill valve, actuator valve or the ****ty pump.


Any help would be appreciated.

Question: What are you using to fill these larger systems and what fittings are you having to get. No way this little hand pump will do it that I can see.

I use a regular automotive air compressor, the small 12 volt type sold in many places.

If you have that small air valve that Robart makes, toss it and get a regular schrader valve. You can them from Sierra Precision. It makes life so much easier.

As for your proble, we need more details to help you, but I usually use a pair of clamp type forceps, sometimes two of them, to pinch of various lines to islolate leaks, etc.

Beyond that small tip, I don't know what else to tell you for now.....

I'm not sure if this will help but when I put my Robarts in I had the same problem except I was using a power pump. Even then I would still only have about 40 psi. After much troubleshooting I found that the Robart filler was too long so when I would screw on the other end attached to my pump it was not depressing the needle all the way causing about 25% of the air pumped, into the system. I ground off about 1/4 of an inch of threads and it worked flawlessly.

Just an Idea, SVX

SVX, yep that was part of it, fit that with a Sierra fill valve.

Branded, got the sierra valve. My leak was not a leak, just soemthing i screwed up. Went to Pep boys and got a small pump, works great, all is well again.