Loaded Tire Valve Stem Failure

[BotaBigot]

Finally happened yesterday...mowing across slope (to stay out of mud at bottom) apparently put enough pressure on down side tire to "blow" metal part of valve from rubber body...cheap Chinesium valves...this is second valve failure...first was front...started losing air...while filling noticed air chuck was making metal part move...replaced...now conclude quality control issue vulcanizing rubber to metal...thanks Kubota, hope you saved lots of money...

Strange sensation to look down and see water spraying from l rear side tractor...did "finger in dyke" and looked for something to plug leak...fortunately had lynch pin in cupholder...perfect fit...whew!

Don't know yet how much solution lost or how will repair...tempted to try quick-and-dirty "valve install from outside" scheme to keep from draining tire...need tractor, got stuff to do...

 

[AStanton]

If that happens to my loaded tires, I already decided to get em foamed.

 

[kco]

Are the tires just filled with water? The reason I ask is because beet juice ballast (Rimguard, BioTire, etc) degrades the glue bonding the valve core to stem over time and the core will let go.

Beet juice filled need proper valve stems. This is a quote from the "dealer" section of the Rimguard site:

======= start quote ====
With tubeless tires, replace rubber valve stems with brass valve stems. Rubber valve stems sometimes turn in the rim hole because Rim Guard is slippery. In some rubber valve stems the brass core is held in place by adhesive. This adhesive sometimes dissolves over time (1-1/2-2 yrs.) and will allow the core and Rim Guard to be suddenly expelled when the valve stem cap is removed
======== end quote ====

 

[xtn]

Everything needs proper metal valve stems. I friggin HATE those cheap rubber ones.

Took me forever and a day to figure out why my car was losing air pressure in the tires. Only while going down the road... not ever while the car sat parked. Tiny cracks in the rubber stems only opened up when they were subjected to centrifugal force.

xtn

 

[BotaBigot]

Are the tires just filled with water?...

Calcium chloride

 

[BotaBigot]

Everything needs proper metal valve stems...

Don't know how would hold up when bumped...which happens from time to time...wish Kubota had put half-round stem protectors on rims...I'm dreaming of course...they didn't use decent stems...

 

[zmansmac]

I have this problem with my 9 year old B7500. One of the rear tires, which is loaded with beet juice had the core let go. Fortunately I didn't loose much juice before I put the metal cap back on. This happened last fall and I didn't have time to take care of the issue then so I put a small S.S. hose clamp around the stem. This seemed to hold the core in place and I ended up forgetting about it until I saw this thread. I'll have to talk to my dealer about getting better stems installed.

JohnZ
B7500

 

[BotaBigot]

Kubota back in service...

Removed tire and laid on backside, made halfhearted attempt to break outside bead...no go...

Split old stem w/sharp knife and removed w/needlenose pliers. Ruined first new stem...didn't take my time, plus soaping made harder to control dull screwdriver used for pushing. Took my time with second stem and no soap made it easier to control screwdriver, plus pushed rubber stayed put.

After stem in, soaped and rotated with waterpump pliers to seat. Longer stem would have been easier to collapse and push thru, but wanted 3/4".

Remounted wheel, valve at top. Aired to max pressure to seat...spit liquid, so must not have lost much. When have time, will weigh each rear tire to see how much solution lost (8# per gal).

Worked rest of day...no leaks...:thumbsup:

Keep a 1/4" lynch pin handy just in case...

 

[crazyal]

I'm not sure if rubber valve stems are made anywhere but China now.

 

[whistlepig]

Calcium chloride

The valve stems will go first with calcium chloride. The rims will go next.