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.

You may have pinched the valve stem just enough to crack it. If you can, apply a solution of soapy water on the stem and look for bubbles. If that's not it, you can do the same to the rest of the tire to find the leak. I always carry a kit to repair tubeless tires. I fix them myself in 2 minutes.

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.

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.

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.

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.

Any hints about why my tire leaking? | Good Sam Community

jdc1
Explorer II
Mar 22, 2020
You may have pinched the valve stem just enough to crack it. If you can, apply a solution of soapy water on the stem and look for bubbles. If that's not it, you can do the same to the rest of the tire to find the leak.
I always carry a kit to repair tubeless tires. I fix them myself in 2 minutes.
Lwiddis
Explorer II
Mar 22, 2020
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.
wopachop
Explorer
Mar 22, 2020
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.
dieseltruckdriv
Explorer II
Mar 22, 2020
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.
time2roll
Nomad
Mar 22, 2020
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.
MarkTwain
Explorer
Mar 22, 2020
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.
azdryheat
Explorer
Mar 22, 2020
So inflate the tire and take it the nearest tire store for repair. It's not going to be anything you can fix anyway.
wopachop
Explorer
Mar 22, 2020
Totally depending on tire age it might be worth calling around for a price to install 4 new metal valve stems.
wa8yxm
Explorer III
Mar 22, 2020
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.
down_home
Explorer II
Mar 23, 2020
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.