Repair or replace??

[Bryanpark2]

30 miles from our destination my TPMS indicated low pressure. Indeed it was. Had gone from 65psi this morning to 52 psi after 200 miles. Bought all four Goodyear Marathon ST225/75/R15 2 months ago. All codes indicate they were made in late 2015. I inflated back to 65psi and made it to the campground but it still lost 2 psi in that 30 miles. What to do with slow leaking tire. Can someone come and repair or is a new tire necessary. I have about 4 days before return trip. By the way we have traveled a total of 1800 miles the past two weeks.

Thanks in advance for the advice.

George

[RBPerry]

Get a spray bottle, fill with water and add some dish soap. Spray around the tire until you find the leak. When the soapy water hits the air leak you will get bubbles. If it is a nail, don't pull it out. Now I always carry tire plugs with me, I know they aren't the best but they will plug a small hole.
If the leak is in the sidewall you will need to replace the tire.

[time2roll]

Put the spare on and head home as scheduled.
Have the tire repaired at home at your convenience.
If repair is not recommended then by all means get a new tire.

[_1nobby]

Huntindog wrote:
I think the OP is concerned about what hidden internal damage the tire may have suffered when running under inflated.

This is a valid concern. Especially since ST tires do not have to pass an underinflation test like LT tires do.

I would replace the tire. If the tire has been damaged, a blowout can occur without warning. The resulting damage to the TT that can occur will likely be MANY times the cost of replacing the tire.

Holy Sh*t! Does everyone drink from the same bowl of Koolaid??

[Bryanpark2]

Thanks for all the responses. I believe the sensor on that tire was shaken a little loose by the extremely rough road of I 10 in western Louisiana. I don't believe I have ever been on a major road in that condition. I had a tire guy come to my site and check for leaks and found none. It has been 24 hours and no further lose if air pressure. Keep you fingers crossed. In a couple of days we make the trip home from Beaumont back to North Myrtle Beach!

[rexlion]

I'm with dewey02, I would not be too concerned about tire damage from that short time of under-inflation. I would bet that the low tire is on the rear axle of your TT, and that it's gotten a nail or screw embedded in the tread. So many times I've had punctures in the rear ones and rarely in the front tires; the front ones seem to throw the nails up into position for the rear tires to impale themselves. Odd are, you just need a patch and you'll be good to go.

[dewey02]

Huntindog wrote:
I think the OP is concerned about what hidden internal damage the tire may have suffered when running under inflated.

This is a valid concern. Especially since ST tires do not have to pass an underinflation test like LT tires do.

I would replace the tire. If the tire has been damaged, a blowout can occur without warning. The resulting damage to the TT that can occur will likely be MANY times the cost of replacing the tire.

I am no tire expert, but I find it extremely hard to believe that a tire will experience internal damage from running 20% under pressure for a total of about 300 miles. It may be different if the tire pressure had gone extremely low. But 52 pounds in a 65 pound tire shouldn't be terminal by any means.
Again, just my opinion as I am not a tire expert. I agree with those that think this is either a valve or tire bead leak, or perhaps a small nail puncture with the nail effectively sealing most of the leak. This is a new tire. Get it fixed.

[myredracer]

Don't blame the tire straight off without checking other things first.

Try swapping the sensor onto another wheel and see if that loses air. If it does, it's the sensor. Check the valve core to see if that is faulty.

Did you have new metal valve stems installed? If you did, it's possible that the tire shop messed up the grommet between the rim & valve stem. That's what happened to us. I had another tire shop install a new grommet on the inside and outside of all 4 rims. I stood there while the guy did the work to make sure he was careful. Zero leaking air after that.

Tire shops often have employees that do sloppy work. Ask a shop if they've had experience with valve stems for TPMS sensors first and ask who'd be the guy doing the work. The shop I originally went to get new metal valve stems installed claimed they couldn't get the grommets to fit into the hole on the outside of our aluminum rims so they installed them on the inside, despite the manufacturer having designed them to fit on the outside. When I eventually had all 4 rims redone, all that was needed was a bit of lube and some patience to massage the grommets into the holes. Aluminum and steel TT rims typically have a curved surface on the inside of the rim where the valve stem is and isn't a good mating surface for tightening the valve stem metal washers against. A grommet on the inside of a metal valve stem can be a good thing as the psi inside the tire forces the grommet against the rim.

If after inspecting the valve stems air still leaks, a tire shop can check for leaks in a dunk tank.

[schlep1967]

I replaced the tires on my 5th wheel 3 weeks ago. I did them one at a time taking the wheel/tire off and delivering it to the garage to be changed. The first one I put back on the trailer was flat the next day. Bad valve core in the new valve stem. Replaced the core and all is fine now.

Check the valve stem.

[ADK_Camper]

Oasisbob wrote:
I start simple. Put some spit on your valve stem and see if it is leaking. If no leak have it re mounted. Sorry. What a hassle on new tires

I did exactly this with a slow leaking tire. The fix was to screw the valve in a little tighter. That was three years ago, no problem since.

[Oasisbob]

I start simple. Put some spit on your valve stem and see if it is leaking. If no leak have it re mounted. Sorry. What a hassle on new tires

[kaydeejay]

Tom/Barb wrote:
Are you certain it isn't the TPMS that is leaking?

Mix up some soapy water and spray the tire down and find the leak. Where it is leaking determines the repair.

I echo that! Much as I love my TST TPMS system it was the cause of two low tires.
One was a cracked valve stem caused by the weight of the sensor (fixed with metal stems), the other was a leaking gasket in the sensor to stem connection.
The good news is that the system did alert me before any damage was done!
It's worth a check!

[rbpru]

I had a TT tire go flat, it was repaired like any other tire.

[Huntindog]

I think the OP is concerned about what hidden internal damage the tire may have suffered when running under inflated.

This is a valid concern. Especially since ST tires do not have to pass an underinflation test like LT tires do.

I would replace the tire. If the tire has been damaged, a blowout can occur without warning. The resulting damage to the TT that can occur will likely be MANY times the cost of replacing the tire.

[newman_fulltime]

My bet is on a bad valve stem