Nose loses PSI faster than mains

ArrowFlyer86

Pattern Altitude
PoA Supporter
Joined
Jul 17, 2019
Messages
2,093
Location
Chicago suburbs
Display Name

Display name:
The Little Arrow That Could
I've been diligent about checking tire pressure ever since a nose-wheel tube went flat in September and stranded me overnight off home base.

In doing this I've noticed my brand new nose tire loses pressure faster than my mains.

While I might only lose 2psi in my mains between checks (LH/RH seem to always match), it's common I'll lose 8psi in my nose gear over the same time. The nose has a brand new tube installed in September, mains are same make but 1 year old.
Only idea was wondering if it was measurement error on my behalf... The smaller volume of the nose tire being more impacted by that couple seconds of HISSSSSS where it bleeds air out while I'm connecting/disconnecting the inflater each time. But that's just a WAG.

Any thoughts from the crowd? :)
 
First guess would be valve having a slow leak. Some soapy water would show if that is the problem. It can be tightened if that is the case
 
I know I am opening a big can of worms but...My tires and struts hold nitrogen much longer then compressed air.
I also have noticed my wife's and I bike tires stay up longer with nitrogen than with compressed air. I don't think I am imagining it.
Like said soapy water is what to use to check for leaks.
 
First guess would be valve having a slow leak. Some soapy water would show if that is the problem. It can be tightened if that is the case
I know I am opening a big can of worms but...My tires and struts hold nitrogen much longer then compressed air.
I also have noticed my wife's and I bike tires stay up longer with nitrogen than with compressed air. I don't think I am imagining it.
Like said soapy water is what to use to check for leaks.
Thanks guys. I'll use soapy water and see if there's anything noticeable.

I'm using compressed air not n2 for the tires.
A few months ago I looked at getting a nitro bottle from airgas so I could use N2 (and so I could add to my struts, when needed). But with the tank cost, the regulator, the adapter to actually fill up the tires... Juice wasn't worth the squeeze on that one. I think it was like $600 for the most basic solution. Compare that to a $50 air compressor :)
 
Is the air the same temperature every time you're checking it?
Yeah, it's in a climate controlled t-hangar. And I only check it when I'm arriving at the hangar and it's been sitting overnight. So I think it's at a near constant temp.
 
Stan’s No Tubes and Orange Seal are in all of my airplane tires and I have both on my shelf in the hangar. Look on-line or at a local bicycle shop. My 35” Bushwheels ($4700 for the pair) had Orange Seal injected before they got valve cores and air.
 
I have an electric unicycle KS14D. I was having a terrible time with it losing pressure and changed the 14 x 2.125 tube twice. I found the new tubes had leaks along the seams of the tube. I used a can of Fix-A-Flat. Problem solved.
 
Could be several reasons. But first I'd service the tire to max pressure then mix some Dawn and water and spray the whole tire. If you have wheel fairing installed take it off. For example have seen very slow leaks at the tire awl vents.
Appreciate it, I'll give that a whirl today
 
Michelin airstop tubes greatly reduce leakage. There are also leakguard tubes which perform better than standard tubes, but the Michelins are the best, IMO.

You may have one type of tube in the mains and a different one in the nosewheel.
 
Thanks guys. I'll use soapy water and see if there's anything noticeable.

I'm using compressed air not n2 for the tires.
A few months ago I looked at getting a nitro bottle from airgas so I could use N2 (and so I could add to my struts, when needed). But with the tank cost, the regulator, the adapter to actually fill up the tires... Juice wasn't worth the squeeze on that one. I think it was like $600 for the most basic solution. Compare that to a $50 air compressor :)
Yea I know that stuff is expensive. Over the years I have used nitrous oxide in race cars and CO2 for beer taps. I have 8 nitrous tanks that got swapped out after every run. I ran 2 of them side by side in the nose of a dragster. Not using nitrous any more so I converted a couple of those tanks to nitrogen by installing a nitrogen valve. We send tanks out for hydro test since we fill CO2 at work so the tanks are kept in test.
Then we use large nitrogen tanks at our bulk plant for emergency shut offs. I refill my small tanks with a trans fill hose from the large tanks. Pretty much the same way I refilled my nitrous tanks from the mother tank. So I don't have take it somewhere to refill it.
14513c6d-318a-4cf9-85c9-11c795919f1e.jpg



We also used these small CO2 tanks that got switched out every run to shift the transmission. That is a trans fill hose.
595b972c-3c34-4514-af14-7bc4b1292999.jpg

How I shifted the transmission.
9f5a4bef-a41b-45be-ac8e-f0e661b700cd.jpg
 
Last edited:
I keep a nitrogen bottle in the hangar for my shocks. No need to put it in tires. Solve the porosity issue and the pressure won’t bleed out.
 
Michelin airstop tubes greatly reduce leakage. There are also leakguard tubes which perform better than standard tubes, but the Michelins are the best, IMO.

You may have one type of tube in the mains and a different one in the nosewheel.
I have LeakGuard on all 3.
The former nose tube (also leakguard), got a pinhole leak and ran flat in september. The FBO only had leakguard tubes as an option if I wanted to get out that day. So that's what I got :)

Yea I know that stuff is expensive. Over the years I have used nitrous oxide in race cars and CO2 for beer taps. I have 8 nitrous tanks that got swapped out after every run. I ran 2 of them side by side in the nose of a dragster. Not using nitrous any more so I converted a couple of those tanks to nitrogen by installing a nitrogen valve. We send tanks out for hydro test since we fill CO2 at work so the tanks are kept in test.
Then we use large nitrogen tanks at our bulk plant for emergency shut offs. I refill my small tanks with a trans fill hose from the large tanks. Pretty much the same way I refilled my nitrous tanks from the mother tank. So I don't have take it somewhere to refill it.
14513c6d-318a-4cf9-85c9-11c795919f1e.jpg



We also used these small CO2 tanks that got switched out every run to shift the transmission. That is a trans fill hose.
595b972c-3c34-4514-af14-7bc4b1292999.jpg

How I shifted the transmission.
9f5a4bef-a41b-45be-ac8e-f0e661b700cd.jpg
Given the other photos you've posted of your hangar and tools, this surprises me very little :)
You've got a much, much more advanced workshop and tooling setup than me with my 1-2 small tool boxes with wrenches and screwdrivers. I think my most "advanced" tool is a torque wrench :p
 
I've been diligent about checking tire pressure ever since a nose-wheel tube went flat in September and stranded me overnight off home base.

In doing this I've noticed my brand new nose tire loses pressure faster than my mains.

While I might only lose 2psi in my mains between checks (LH/RH seem to always match), it's common I'll lose 8psi in my nose gear over the same time. The nose has a brand new tube installed in September, mains are same make but 1 year old.
Only idea was wondering if it was measurement error on my behalf... The smaller volume of the nose tire being more impacted by that couple seconds of HISSSSSS where it bleeds air out while I'm connecting/disconnecting the inflater each time. But that's just a WAG.

Any thoughts from the crowd? :)
You should consider temperature changes.
Also if you do the soap check make sure to check the valve stem.
 
Stan’s No Tubes and Orange Seal are in all of my airplane tires and I have both on my shelf in the hangar. Look on-line or at a local bicycle shop. My 35” Bushwheels ($4700 for the pair) had Orange Seal injected before they got valve cores and air.
Which version do you use, Regular or Endurance, and how much? Am I correct to assume the following process? The valve core is removed, the goop squirted in, valve core replaced, tire inflated, and go taxi fast.
 
First thing is to stop using an inflator kit to check pressure. Use a stab only type gauge. The only time we hook an inflator up to a tire is to actually inflate it. All daily tire checks are done with a stab gauge. I can stab a nose tire for about 10 days of checks before I need to bring the pressure up on it. Our nose tires run 270 or 300 psig nominal, depending on A/C model.
 
First thing is to stop using an inflator kit to check pressure. Use a stab only type gauge. The only time we hook an inflator up to a tire is to actually inflate it. All daily tire checks are done with a stab gauge. I can stab a nose tire for about 10 days of checks before I need to bring the pressure up on it. Our nose tires run 270 or 300 psig nominal, depending on A/C model.
Sounds like an easy first step to take, thanks! Any specific ones you'd recommend or are they all pretty much the same accuracy?
 
Sounds like an easy first step to take, thanks! Any specific ones you'd recommend or are they all pretty much the same accuracy?
Ours are Mil-Spec Miltons, but they go to 750 psig. Milton, Longacre or Intercomp are all high quality. We've gone to all digital at work and are phasing out the analog and stem type gauges. I wouldn't drop the coin on any of them being above around 50-75$, as you don't need that kind of accuracy and repeatability. If you like analog dial only, there are a number of them that are not at that price level. Just remember, dropping an analog dial gauge, even a foot to a hard surface can knock it out of calibration.
 
Which version do you use, Regular or Endurance, and how much? Am I correct to assume the following process? The valve core is removed, the goop squirted in, valve core replaced, tire inflated, and go taxi fast.
That’s the procedure. Stan’s uses a syringe to inject, Orange Seal has an injector tip on the bottle. I’ve ised both. The Orange Seal I have is the non-freezing type but I don’t think it matters if you inject it in warm temps. I did mine in the hangar and spun the tires for a couple of minutes. No air adjustments needed since, and that was 6 years ago. Longer on the Cessna with Stan’s.
 
Only idea was wondering if it was measurement error on my behalf... The smaller volume of the nose tire being more impacted by that couple seconds of HISSSSSS where it bleeds air out while I'm connecting/disconnecting the inflater each time. But that's just a WAG.

So then double thd pressure check period and see if the pressure loss is halved :D
 
So then double thd pressure check period and see if the pressure loss is halved :D

But would it be halved? :oops:
Or I could...
1) Inflate tires to appropriate pressure, then disconnect.
2) Immediately reconnect inflater and check the pressure
3) Any difference btw inflation pressure and the new pressure could be chocked up to the loss from unplugging/plugging it back onto the tire valve.

*chin scratch...

Ours are Mil-Spec Miltons, but they go to 750 psig. Milton, Longacre or Intercomp are all high quality. We've gone to all digital at work and are phasing out the analog and stem type gauges. I wouldn't drop the coin on any of them being above around 50-75$, as you don't need that kind of accuracy and repeatability. If you like analog dial only, there are a number of them that are not at that price level. Just remember, dropping an analog dial gauge, even a foot to a hard surface can knock it out of calibration.
Thanks for the rec. I'll get a reasonable quality one and stop using the inflater gauge as my only means of checking pressure.

Still going to do the soapy water test today and see what that looks like. Will report back.
 
I’ve had bad luck with tires, now my rule is don’t touch it, and once you got a decent tube in, seems to last much longer. Those valve stems are sensitive, better to not touch it, especially when not at your home airport, and carry spares in the baggage compartment.
 
Back
Top