Main tube leaking air.

[J0nathan225]

Are straight valves the right answer on M20E's main wheels? My tube is losing air, looks like the rubber stem has a small leak from the angle it has to be at. 

Anyone know of a weekend mechanic shop near aircraft spruce that could help me out this Saturday? 

[lamont337]

My old tubes were similar and would rip on the back side where it is being stretched. I switched to Aero Classics with 90 degree stems to stop the tearing, but I can’t say they hold air very well. Have to add a few psi every 2-3 weeks it seems. Would be interested to know what others are using as well. 

For reference, here’s what I have now: https://www.aircraftspruce.com/catalog/lgpages/aero_tube_600_6_67a.php

[Hank]

I have very good luck with Michelin Air Stop tubes, also from Spruce. They cost about as much as the tires, and I replace tubes when replacing tires. If my Mooney was out of the shop, I'd help you on Saturday. Bring some baby powder.

[WilliamR]

Just sent you a PM

 

 

[WilliamR]

Oh, and +1 on the Airstops.  They also have a right angle stem.  Thinking of it, I'm not sure what type of stem is on mine.  But, assuredly, they are not long and bent like yours.

 

William

[RLCarter]

@J0nathan225 was the valve stem straight when the tire was installed? Landing with low tire PSI will allow the tire to rotate (slip) on the wheel, eventually it will pull the valve stem off the tube. 

[MIm20c]

The airstops that I’ve used still have a straight valve stem which is a pain. However, I agree with the above that it was not oriented correctly when installed or the pressure got too low and spun the tire/tube slightly. 

[J0nathan225]

Thanks for the help today, learned how to change a tire thanks to @WilliamR. It did appear the tube had shifted causing the stem to develop a leak. All good now with a new Michelin tube!

[Yetti]

looks like you ran it at low air pressure which allowed the tube to rotate in the wheel.   That then cut the stem.   Need to check air pressure regularly

[cliffy]

There are 2 types of valve stems short and long Just try finding the short ones- harder that heck, they just aren't available. The long ones will always interfere with the axle and they will always leak.

Its been said by some that 800x6 tubes with 90 degree metal stems work perfect in 600x6 tires and last the life of the tire. 

New tubes always go with new tires due to stretch They will never work the second time around. 

They also get thinner as they get flexed in use, just look at the rubber particles in the tire when it comes apart. 

Rule #1 on changing a tire  DEFLATE IT AND REMOVE THE VALVE STEM BEFORE YOU EVER LOOSEN A WHEEL NUT (should be done before you even loosen the axle nut, what if you have a broken wheel bolt? What's holding the wheel halves together? also been there-seen that)). IT CAN KILL YOU IF YOU DON'T-  BEEN THERE SEEN THAT!

THIS IS NO JOKE!

Edited March 31, 2019 by cliffy