CraigG

My Feedback: (40)

Be careful with the "equivalent" lube (and not just because you mispelled it). Some lubes are incompatible with the O rings and could make the situation worse.

Craig

FILE IFR

Hi Pete,

The "O" rings got covered here, but there's one thing I'd like to touch on about air line/nipples.

During the installation of air lines to cylinder, coupling and Tee's nipples we may need to cut off and re-do an airline. Some people will just slit the line with a knife while it's on the nipple. This CAN be done, but it's risky to do as some may scratch the brass/plastic with the knife by going a little too deep.... This CAN cause air leaks!

Below is a trick I learned for getting the air line off the nipple without damage to the nipple (demonstrated on an old Rhom-Air valve).

EDIT: My girlfriend took these pics... after she viewed these she yelled at me to cut my fingernails while I'm at it! [>:]

DrV

My Feedback: (2)

Does anyone have any objections to using thin silicone shock oil made for the RC cars? I have been using this for a while without any problems.

tamjets

My Feedback: (2)

That is the same stuff as silicone grease. It work great for O-ring.

Pete737

Hey Mike,

That's a good trick, Thanks.

I hacked up my air tanks nipple pretty good between all the trial and error. Even so, It is not leaking...

I think Im gonna put small zip ties on everything. I also picked up some silicone lube today....

Thanks, Pete

Gordon Mc

My Feedback: (11)

I agree about using haemostats to isolate the leak via a binary-chop method. Been using this method for decades and it works great.

Re the tees - the best IMO are the clippard ones. They never leak, and the barb is a high quality one that prevents airlines popping off as happens with some other tees.

Last but not least - make sure you do a leak check in both gear down AND gear-up modes. So many people test the aircraft only with it sitting on its gear...

Gordon

tamjets

My Feedback: (2)

Gordon,
You must be lucky on that clipart Tee.
First time I order them. Guess what. I got few leak.
Only one are bullet proof are the solid piece like John photos. But is not cheap.

Gordon Mc

My Feedback: (11)

In case its not clear from the photos - the clippard ones ARE solid, one-piece components.

Gordon

tamjets

My Feedback: (2)

O.K.
The one I bought while back must be different one sold by clippart.
It look exact like in the picture. It was press fit and nickle coating after worth.

BTW,
The GF board just done.

Pantherman

Very timely thread for me guys. Putting the gear into my Panther and had a bad leak. I used the tip listed earlier of the piece of fuel tubing as a stethascope, and found the leak very quickly. It was at the piston exit from the cylinder. I added some thin lube and viola, no more leak. Thanks for the fuel tubing tip. Worked like a charm!

Woody

rcdoug

My Feedback: (8)

I am happy that Gordon brought up the hose popping off problem.
I have been wondering why builders have been using the "heavy duty" air lines. Do they have less of a tendency to pop off from high air pressure when you don't safety them? Is it a pressure problem? I have used Robart hose and tees without safetys and had no problems with pop offs or leaks, or blowouts (100 psi).
I started using the HD tubing because of the various collors available. I do safety them when I am using tees with a short nipple.
Back to the question. Why do you use the HD line?

The acceptable leak: On a system with O-Ring cylinders, tight fittings, no leaking components, you should have no leakage as long as there is enough pressure in the system to keep the O-Rings seated.
There is normally allowable leakage while a unit is moving, but at rest and pressured up there should be none. Normal air is dense enough to not be a factor in any migration through the O-Ring or tubing.

Thanks for all of the previous posts. There are many great suggestions. The Jets-n-Stuff tees and keepers look great. Pricey, but what did you pay for the rest of the plane.

Thanks and happy holidays,

Doug

Woketman

My Feedback: (6)

Anyone know what the generic form of "ThinLube" is that is compatible with the O-rings in Robart retracts?

Thanks.

cactusflyer

My Feedback: (4)

Yes, they are pricey, but just imagine your pretty new bird sliding on it's belly down a 200' long , 50 grit, sanding bar.......What is it worth to avoid that? Those fittings coupled with the Safeties and Tams failsafe help prevent the catastrophic failure and protect against the slow leak. The fittings that we sell have a proprietary design barb.....Unlike any other.

Most of my leaks have been related to door cylinders as of late, next would be the retracts themselves. My A-7 has two systems. One for retracts only and it holds air with no leaks for weeks. The other system has brakes and doors and it has been problematic. It will loose 30 psi over 30 minutes.

Tailwinds,

John

Gordon Mc

My Feedback: (11)

If by "heavy duty" you mean the stiffer polyU airline such as BV supplies – that tubing is less prone to come off of nipples etc simply because the softer the tubing is the easier it can temporarily 'deform' and pull off the tee (or blow off in a higher pressure situation).

The size of the barbs on the tee, the durometer rating of the airline and the pressure in the system all play into how easily or how hard the airlines can come off, so each is an opportunity for us to prevent problems.

Gordon