Maintaining air pressure in your tires

[Booner]

I've had my RV for less than a year and I'm religious in checking it's tire pressure. I had an inside rear dual that always seemed to loose a little tire pressure, so I checked pressure often. I thought I may have to take this tire to a shop to have it remounted.

I went to an auto parts store and purchased a little screw driver looking thing that is used for inserting the tire valve into it's stem. (I'm sorry I don't remember what it's called). Like I said, the tool looks like a small screw driver with a slot cut into it's stem. The valve fits into this slot and allows you to screw the valve into the tire valve stem. It costs a few bucks.

I fit this little tool into the valve stem on my leaky tire and found that the reason I was loosing air was the valve was a little loose in the stem which allowed a bit of air to leak around the threads that holds the valve within the stem. It took almost a full rotation of the tool in the tire stem before the valve was firmly seated in the stem.

I tightened all of valves on all of my tires and they all have held their air pressure since I did this. For a few dollars this little tool gives me some peace of mind.

I just looked it up and the tool is called "a GVX Valve Core Removal Tool" - under $7 on Amazon. I purchased mine at a local car parts store.

and a link--> https://www.amazon.com/GVX-Valve-Core-Removal-Tool/dp/B01IE7EL1E/ref=sr_1_5?dchild=1&keywords=Schrader+Valve+Tool&qid=1624644307&sr=8-5

[scbwr]

I have a golden rule that each time we stop with our rig, as soon as I exit the MH, I do a walk around of the entire rig and specifically check the tires, hitch, etc.

The second rule I'm trying to follow is to slow down and take your time when it comes to setting up and breaking down my rig. And, I'm trying to train myself and use the checklists I've created. Taking a bit more time and using checklists can help you to avoid costly repairs.....don't ask me how I know this!:o

[Gjac]

https://www.amazon.com/Slime-20088-4-Way-Valve-Cores/dp/B0020T17J2?ref_=ast_sto_dp. This is what I carry in the MH. My tires lose very little air over a year. But in the past on a few occasions over the last 15 years and 100k miles of travel I have had the cores leak very slightly. I put some soap and water on the valve stem and noticed a bubble every now and then, I would tighten them with the tool and see if the bubbles went away, and usually they did. On one occasion I had to remove the valve stem and insert a new one. For a $1.98 for the tool and 4 valve stems it is good to carry with you. If you notice you have to add air all the time check the valve stem with soap and water you may have to just tighten the valve stem.

[Guardpasser5000]

I've had 2 blowouts and 1 leak all related to valve stems. Got all 6 changed and made sure they used high pressure rubber stems with the metal filler deal. Did a 1000 mile trip with no problems. Also religious about tire pressures. Each incident I had checked them pre-trip. Super paranoid now.

[NamMedevac_70]

Unlike Texas with high heat and humidity in northern dry Nevada my LT tires on two trucks never lose air pressure and I check them regularly. When living in central Texas I was constantly having to add air to same tires on 3 trucks and a TT.


I enjoy being a bully to other bullies on another forum. Cheers

[CSUtah]

looking for good tires for an RV C-Class we had Michelin LT and they went 7 yrs. They don't make that tire anymore what has been good for other C-Class?

[jjrbus]

I'll second the China solar TPMS. I use a set of 4 on the duals. Not NASA accurate and have some quirks but never fail to report a loss of pressure. They tend to last about 2 years and I buy 2 at a time as there are no replacement sensors available.

I use to spend too much time trying to balance psi in tires, the TPMS showed me pressures are all over the place. The outer tire in direct sun can have higher pressure than the inner dual and sun side tires will be higher psi that shade side.

Picked up a nail during the day and was losing pressure, inside dual of course! Would not have known without the TPMS and would have ruined 2 tires. Unless of course you think that driving all day on one tire does not hurt it?

[DrewE]

I use "Gator caps" (Alligator V2B) on my motorhome, which are metal air-through valve caps with secondary seals. I do highly recommended for convenience and quality. Do make sure to get them nice and snug when installing, not always a simple task for dually tires with standard stems (unless you have the wheels off).

[CapriRacer]

ScottG wrote:
A while back I stumbled upon an article that indicated the schrader valve isn't supposed to be the main device for holding air in a tire, the cap is.
I always buy metal caps with rubber seals just in case the schrader starts leaking.

As a tire engineer, allow me to correct a few things.

First, the Schrader valve IS the main device holding in the air. The metal cap is a back up.

And I recommend using the metal cap.

[Grit_dog]

ScottG wrote:

Grit dog wrote:

ScottG wrote:
A while back I stumbled upon an article that indicated the schrader valve isn't supposed to be the main device for holding air in a tire, the cap is.
I always buy metal caps with rubber seals just in case the schrader starts leaking.

With all due respect, that article had to have been in the National Enquirer right under the "Les Schwab was abducted by aliens" article!

I didn't catch any respect there but as an engineer type, I keep my mind open to learning new things about absolutely anything and never let preconceived notions keep me from doing so.

Anecdotal. Back in 1978 my buddy's brother allowed us to use his brothers new Corvette for an evening. For some reason long forgotten, we checked the air pressure in the tires. One tire had a slight leak at the schrader valve when I checked it. Being a dumb 17 y/o kid, I just screwed the cap back on and we went on our way.
That tire held air all night and was still up the next day when I dropped by their house.

A metal valve stem with a gasket will hold some pressure. ( I used one on a leaking valve core in a pinch, had to swipe it off a random vehicle in the parking lot. Probably should have left him a dollar, lol but desperate times called for desperate measures...) And even a plastic one will help a little if it's low pressure I imagine, but a valve stem cap is 100% not designed to be the primary or even secondary means of keeping air in a tire.
Think about it. If they were, they would be much more robust and not standard plastic. They are primarily to keep crud out of the valve stem.

[ScottG]

Grit dog wrote:

ScottG wrote:
A while back I stumbled upon an article that indicated the schrader valve isn't supposed to be the main device for holding air in a tire, the cap is.
I always buy metal caps with rubber seals just in case the schrader starts leaking.

With all due respect, that article had to have been in the National Enquirer right under the "Les Schwab was abducted by aliens" article!

I didn't catch any respect there but as an engineer type, I keep my mind open to learning new things about absolutely anything and never let preconceived notions keep me from doing so.

Anecdotal. Back in 1978 my buddy's brother allowed us to use his brothers new Corvette for an evening. For some reason long forgotten, we checked the air pressure in the tires. One tire had a slight leak at the schrader valve when I checked it. Being a dumb 17 y/o kid, I just screwed the cap back on and we went on our way.
That tire held air all night and was still up the next day when I dropped by their house.

[Grit_dog]

ScottG wrote:
A while back I stumbled upon an article that indicated the schrader valve isn't supposed to be the main device for holding air in a tire, the cap is.
I always buy metal caps with rubber seals just in case the schrader starts leaking.

With all due respect, that article had to have been in the National Enquirer right under the "Les Schwab was abducted by aliens" article!

[ScottG]

A while back I stumbled upon an article that indicated the schrader valve isn't supposed to be the main device for holding air in a tire, the cap is.
I always buy metal caps with rubber seals just in case the schrader starts leaking.

[btim]

Thanks Grit and Drew. We are headed cross country from Fla. to Yellowstone area this week. Hope the heat out west breaks soon.

[DrewE]

btim wrote:
I have TPMS on my Class C E450. I keep the tires inflated to mfr recommended psi. I also keep the TPMS display on while driving so I can monitor the pressures. I get a bit alarmed watching the pressures rise as I travel, especially in hot weather. Is it normal to see the pressures go from 80psi to 90psi or higher? I do not want a blowout! How accurate is the Ford TPMS system? It is usually within 1-2 PSI of my Slime tire pressure gage. But how accurate is that thing?

Yes, it's normal for the pressure to go up that much with temperature while driving. That's why the pressures are stated as cold pressures. The tires and wheels are designed to withstand the additional pressure encountered while in use with a sufficient margin for safety (assuming you're not doing silly things like greatly exceeding the speed or weight ratings of the tires--particularly both at the same time).

If your slime guage is a digital gauge, it's almost certainly dead nuts accurate, or very close to that. If it's an analog/mechanical one, it may be a little less accurate, but the fact that it correlates well with the TPMS readings strongly suggests that both are plenty accurate for any practical use. Being one or two psi off isn't going to cause any trouble. Perhaps the place where precision matters the most is in matching pressures on the two tires on one side of a dually axle, and there it's matching closely to each other that demands the closest precision, rather than matching exactly the specification in absolute terms.

None of that, of course, is license to drive with significantly overinflated or underinflated tires, which is decidedly not safe.