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A Way To Find Valve Stem When Adding Air

HFS

Well Known Member
There are many ways to "skin" this cat - but this is one that I have used:

Use your borescope, connected to a truncated wooden (cork or ?) cone, with a hole in the middle for your 'scope camera, and sized to wedge into access hole in WP.

Bring up the 'scope image on your phone - roll the airplane forward (or back) until valve stem is centered. Voila!

YMMV

David Howe
 

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Frankly I use a much lower tech approach.

I mark the tire side using nail polish where the valve stem is aligned with the hole and then always push the aircraft until the paint line is perpendicular to the ground. This ensures the valve stem is in the right place for inflation using a five inch truck tire extension valve.

Also use aluminum valve caps for easy off/on with a socket wrench.

Since I’m old and don’t bend easily it takes 15 minutes to check tire pressures (excluding nose wheel which can add another 10 - 15 minutes).
 
+1 for Simple & Low Tech

Frankly I use a much lower tech approach.

I mark the tire side using nail polish where the valve stem is aligned with the hole and then always push the aircraft until the paint line is perpendicular to the ground. This ensures the valve stem is in the right place for inflation using a five inch truck tire extension valve.

I use a silver colored sharpie with the same effect. Wife would get upset if I took her nail polish :D. Then I use a handy valve cap remover and extension that I got from Cleavland Tool a while back. Easy peasy, no batteries required.
 
Finding the Valve stem....

Frankly I use a much lower tech approach.

I mark the tire side using nail polish where the valve stem is aligned with the hole and then always push the aircraft until the paint line is perpendicular to the ground. This ensures the valve stem is in the right place for inflation using a five inch truck tire extension valve.

Also use aluminum valve caps for easy off/on with a socket wrench.

Since I’m old and don’t bend easily it takes 15 minutes to check tire pressures (excluding nose wheel which can add another 10 - 15 minutes).
Yeah, I get the bending over thing......:D

I have the old style pants (which I think look faster.....;)) and did the same thing except my mark is on the wheel with a Sharpie. Bottom of the arch of the wheel: stem is lined up with the hole. I remove the valve stem cap with a short piece of left-over fuel line hose or some hose that fits over the cap and long enough to stick out of the wheel pant. And I have two of those: one in my tool kit and one in my tool box. I put two valve extensions together that I got at a local auto parts store that, together, are long enough to stick out of the wheel pant. I have four of those: two in my tool kit in the airplane and two in my tool box in the hangar. I also have a tire inflation tool (from Cleveland, I believe) that is long enough it reaches inside the pant without the extensions. The extensions are handier to carry in the tool kit. I did get the Cleveland cap removal stick as well but the fuel hose is much smaller and shorter.:):)

It's handy to have some simple system when you are "on the road" as a low tire on a trip can mean removing the wheel pant if you don't have a simple, compact system.

That said, I do like the ingenuity of the scope....:)
 
Lecture me if I need it, but it wasn't long into my RV ownership that I simply left off the valve stem cap. There, I said it :D

I use the mark-on-tire method for aligning the stem with the access hole in the pant, and a flexible inflator is stiff enough to press onto the valve without having to resort to a rigid thread-on extension which is just a liability if the plane rolls while it's in place and poking out of the access hole.

Checking/airing tires is very quick if one isn't futzing with valve caps and thread-on extensions.
 
" it wasn't long into my RV ownership that I simply left off the valve stem cap."

Not perfect all the time, but my solution was a short length of 3/8 fuel line which I glued a shorter bit of 3/8 fuel hose to one end, the hose split at the end about 1/4" with a couple cuts. Just right diameter to grab the tube filler cap for removal & re-install.

edit: correction- looks like it was a 5/16 hose that I split to fit over a chunk of 3/8 fuel line.
 
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Two lines on tire one white for stem the other at 180 degrees red. Can always roll just a little back and forth to know where stem is. Short length of galvanized pipe with quick chuck for air compressor on one side the other a straight tire filler.

Fast and easy.
 
White tire crayon reference mark for valve stem alignment. But I make sure that both inside and outside sidewalls of tire are marked...that way, when I'm rolling the plane fore/aft by tugging on the prop, I can easily see those inside marks.

And yes, I take all precautions when I move the aircraft by the prop!!
 
What type of borescope is that?

David, I've been looking for a borescope to replace my old dental camera. What type of borescope do you use? And the WiFi box?
 
Type Borescope

I'm using something called "EndoSnake" - primarily made for gun smithing work.

It is completely self contained and relies on getting an "app" for your smart phone for the interface.

Plenty easy to use - even for a dinosaur like me!

HFS
 
Tire pressure

I know this is a dumb question, but what tire pressure do you guys run?

Not a dumb question, just off-topic. It's actually a very pertinent question.

I think a lot of it is experimentation but a good start is, in the R-4, main gear: 35 psi. That is a good starting point but can be adjusted up and down depending on mission weight, OAT, runway conditions, propensity for the gear to vibrate, etc. I found changing the pressure made a difference in gear vibration. Going out to a turf runway: 30 or so. I wouldn't go much less than that. I believe you have a -7 about ready to go. Experiment once you get her up in the Test Flight Card numbers.....:) Think about 35 but that is likely open to debate.........:p

Rear gear: zero. Solid tire.....:D:D
 
Lecture me if I need it, but it wasn't long into my RV ownership that I simply left off the valve stem cap. There, I said it :D
I've been tempted to do this but remember that the cap on these tires has an O-ring that can provide some redundancy in the case of a valve stem core failure. Yes it's unlikely, but I also remember it happening to a friend when we were traveling in Canada in our RV-6s, when he landed at one air-carrier airport and had a sudden-ish stoppage on the runway due to a flat. It was subsequently determined to be a valve core failure, and a loose cap. No damage but he wound up blocking the runway with airliners waiting to land. Just something I think about whenever I mess with the cap! Personally I just use a nut driver; it fits okay through the hole in the wheel pant, a little fussy sometimes but works okay.
 
Borescope / Endoscopy

Since your talking about them. I’ve been seeing ads on FB from a company called Diyzit for their duel lens Endoscopy. Self contained with 4 1/2” screen. No WiFi to phone. I have the WiFi type now and it’s a pain. Image jumps and you need the mirror attachment to see the valves in the engine. And sometimes the WiFi looses connection or has trouble connecting at all. Well anyway, if you search Ebay you can get the exact same unit as the Diyzit model only direct from the factory in China and a lot cheaper at about 40 to 50 bucks. Haven’t received it yet but I’ll give a review when it comes in. Those things are really handy in more areas than just the cylinders. :)
 
Lecture me if I need it, but it wasn't long into my RV ownership that I simply left off the valve stem cap. There, I said it :D

Any dirt that gets inside open stem will be available to enter the valve itself when adding air.
Slow leak could develop if the dirt lodges in the valve, stopping it from seating once the filler is removed. Had this happen on a car. Not worth the risk of a flat tire!

3/8" nut driver for my Hex cap works great.

Use a silver sharpie like others to mark the stem with a dot. Once the stem is aligned with the access hole in the pant, I mark the tire at the very bottom with a triangle pointing down at the ground to know the stem is in the correct location. After about 6-months need to remark the tire again.

Mike
 
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Just went through this today. I was by myself, and I used a wing jack to lift the tire so I can rotate it until the yellow-colored hex valve cap is visible in the cutout. I remove the cap with a socket on an extension, and then access the valve with a strait air chuck and built-in gauge. If there's another person there, that's unnecessary as they can just push the plane back and forth for me til the valve is accessible.
 
How about just removing the front half of the wheel pant, inspecting the tires, brake linings, check for signs of fluid leakage and then air up the tires :eek:
OMG the horror!
 
How about just removing the front half of the wheel pant, inspecting the tires, brake linings, check for signs of fluid leakage and then air up the tires :eek:
OMG the horror!

Omg, you’re probably one of those guys that sumps the tanks for water…………:rolleyes:
 
How about just removing the front half of the wheel pant, inspecting the tires, brake linings, check for signs of fluid leakage and then air up the tires :eek:
OMG the horror!

+1
In practice I only seem to need to add air once or twice a year at most (my 7 was the same) so it’s not a big job. Both sides in 10min no problem. 15min for the 10.
 
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