Any hints about why my tire leaking?

[kabbro]

Trailer has been in storage lot in Florida for 3 months, want to leave the state tomorrow so yesterday I checked systems out and was pleased to learn that all 4 trailer tires were still at 50# as required and didn’t need inflation. When I was putting the plastic valve cap back on it seemed like I turned it too far and popped the top of the cap...I did not move the trailer at all yesterday. When I went down this am to hook up, that tire was flat. (Just wanted to emphasize that the trailer and tire was NOT moved yesterday). I have reinflated the tire twice and it slowly leaks. I have done the soap suds routine and there is no evidence of leaking (bubbling air) through the valve stem. I don’t have the jack to change the tire myself and haven’t been able to get any road service to come out...needless to say we won’t be leaving Florida tomorrow morning as planned. Just wondering if any readers can help me diagnose the likely source of the air leak.Thanks.

[ajriding]

yes, the plastic caps just keep dirt out, and do nothing to hold air in. as suggested you probably moved the old dry rot valve. Those need replacing every few years anyway. Usually when you get new tires.
There are metal caps with rubber washers that do hold air in so adds another barrier to a leak.

There is a product I have used for tire leaks (not valve leaks) that creates an airtight seal from the inside. Monster Energy Drink desert racers are sponsored by it and swear to it. It works in my lawnmower tire too and has held a leaky tire up for two years so far.
Truckerco is the product. Unlike Slime that kind-of works at lower psi, this is a latex product that bonds to the tire, will fill in holes or leaks and has done wonders for me and works at 80psi in my truck.
I have seen it on ebay, straight from the company in NV, but Amazon probably not shipping bc of virus right now (Amz only shipping essentials).

[Dave_H_M]

WHOAH WATCH OUT THERE.

you are describing the way my stems on my flat bed acted when they got rotten. I would grab that stem and twist it around some (with my fingers of course) and see if it starts hissing where it comes through the rim. put some soap solution there also.

If that stem is rotten, I would suggest that the other ones are ready to expire also. :h

[Grit_dog]

Metal valve stems aren't even remotely required, although they may be personally preferable, they are not foolproof either.
Even 8 lug trucks come with rubber valve stems these days.

How old are the tires and valve stems? Likely didn't catch the bad valve stem with your soap test.

Another option, if you're in a hurry and don't want to bust the tire off the rim is replace the bad valve stem with a Colby valve. Can get em next day Amazon prime and some good auto parts stores carry them. Very handy. I have one with my on the road tools.
They are a compression fitting valve stem and very robust.

[SidecarFlip]

You twisted the stem where it enters the rim when you cranked down on the valve cap. real simple. Take it and have a new stem put in. I got rid of all those cheap azzed import fake rubber valve stems years ago. They all take a puke eventually, some sooner some later but they all fail.

Get yourself some screw down metal racing stems. One time replacement. Last forever.

[colliehauler]

I would install new metal valve stems in all four tires.

[down_home]

Several years ago we had all four new tires on our F150 go bang, at different times. China junk valve stems. The Dealer and Distributor replaced all four tires. There are probably still some china junk valve stems without UV protection still around.. Second you may have damaged the valve core with a defective plastic valve stem cap. We had a leak on left front on the MH. It was the valve stem being loose. The good stainless caps used on large tire high pressure tires on Mhs and Trucks kept the pressure in,until the pressure was checked and apparently didn't reseal as good.
We had a different problem with our Fifth Wheel tire stems, rubber with brass tube inside someone stepped on and bent/broke them inside and they all leaked.
We replaced them with bolt on or in short stainless valve stems and caps. I would recommend the short stainless valve stems and caps if they will work or a slightly longer one if necessary.

[wa8yxm]

You said the top popped off the cap. You may have some "Debris" inside the outer part of the stem and the valve slightly held open. A flshlight (Penlight size) may well be your friend on this one....

But the advice to seek professional help (Tire store) is good too.

But I'd look down the valve stem also soap it as others have suggested.

[wopachop]

Totally depending on tire age it might be worth calling around for a price to install 4 new metal valve stems.

[azdryheat]

So inflate the tire and take it the nearest tire store for repair. It's not going to be anything you can fix anyway.

[MarkTwain]

kabbro wrote:
Trailer has been in storage lot in Florida for 3 months, want to leave the state tomorrow so yesterday I checked systems out and was pleased to learn that all 4 trailer tires were still at 50# as required and didn’t need inflation. When I was putting the plastic valve cap back on it seemed like I turned it too far and popped the top of the cap...I did not move the trailer at all yesterday. When I went down this am to hook up, that tire was flat. (Just wanted to emphasize that the trailer and tire was NOT moved yesterday). I have reinflated the tire twice and it slowly leaks. I have done the soap suds routine and there is no evidence of leaking (bubbling air) through the valve stem. I don’t have the jack to change the tire myself and haven’t been able to get any road service to come out...needless to say we won’t be leaving Florida tomorrow morning as planned. Just wondering if any readers can help me diagnose the likely source of the air leak.Thanks.

Make sure you have metal stems in your tires.

[time2roll]

I also suspect the vale stem is cracked. You may still have stems from the old recall where they are prone to cracking. Keep spraying the soap on everything until the leak is found. You may need to remove the wheel.

[dieseltruckdriv]

Your valve stem went bad, probably from no fault of yours. My pickup has been sitting since Thanksgiving weekend, and suddenly early March it had a flat tire. I thought that was strange, so I filled the tire back up. Next day it was flat again, so I put some air in it and then wiggled the stem and sure enough I could hear air leaking. I had a metal stem put in it, as this isn't the first time this has happened in that last couple years.

[wopachop]

Do the soap trick again but this time lightly flex the valve stem back and forth. Its probably leaking where the valve stem meets the wheel.

Also make sure to form a soap bubble over the top of the valve stem and watch closely. I slow leak will take a couple seconds to spot.

My guess is that checking the tire pressure upset the valve stem. Either leaking at the base or the shradder valve itself is leaking.

Also your vehicle should have a jack that is strong enough to lift the axle enough to get the tire 1 inch off the ground. While the manufacture does not recommend jacking up the axle its the method i see tire dealers use. I dont see any difference in driving the trailer onto a driveway.

[Lwiddis]

You don’t need a jack with tandem axles. Build yourself a ten dollar wooden ramp. Remove the tire, inflate and submerge. Push the stem different directions.