Community Forums

seadogjim · 03-18-2014, 03:39 PM

Hi,
Have both a "stick" and "gauge" type tire gauges but not sure either is real accurate. Can't seem to get a good pressure reading on one inside rear dually with either gauge. My compressor has a dual foot chuck(as do both tire gauges) with a gauge and the tire doesn't want to accept air. My compressor goes to 150psi and it seems to be operating fine, so putting in 85psi shouldn't be a problem. The gauges seem to work pretty well on the other tires, but not great. The compressor seems to be able to put air in the other tires fairly easily.
Is the pressure just hard to check on 22.5" tires(Michelins)? Could the tire valve be bad on the tire I can't get a reading on or put air in(suspect this is the case since it's mainly the one inside dually with the "flexible" stem that's the issue)? What kind of tire gauge do y'all recommend? Are the digital gauges easier to use?
Of course we all know nothing gets easier as we age, but it doesn't seem like checking tire pressure and airing up a tire shoud be so difficult.

Thanks,
Jim

gruelens · 03-18-2014, 05:03 PM

Hi Jim,
You are to be commended for checking your tire pressures. First off if you have flexible rubber valve stems, it is my opinion that they should be changed to all metal variety for any 22.5 rims.

There are different air chuck "feet" available for gauges and filling . Some have an angled head, some are parallel to the stem (what I need).

Many folks with dual wheels choose a valve extension. These bring the stem location out to the outer dual so you can check/fill air more easily. There is lots of discussion available via the search feature of the forum on the merits of braided lines vs. solid extensions.

Knowing if your air pressure gauge is accurate can be tricky. They are notorious for being inaccurate. If you have a reputable tire store they may let you check yours against theirs. Some RV rallies provide this service. Usually a good digital gauge is fairly accurate. I check my two headed stick gauge against my digital to compare readings (using a valve that faces outward on a single tire).

seadogjim · 03-18-2014, 05:51 PM

Hi George,
Thanks for your reply. One of my problems is the inner duals have valve extenders(look like metal, braided) but are still rather flexible. I have a problem holding the chuck head of the tire gauge or the head for the compressor onto the valve since it'll move when you press on the chuck head. But, the one won't give me a pressure reading and doesn't seem to be accepting air flow when I try to hold the chuck of the compressor line onto it. My compressor line has a gauge and a thumb lever you have to depress to put air into the tire so you have to hold the chuck on with one hand while you watch the gauge and depress to lever with the other hand, not an easy task(at least for me). I guess the rigid metal valve extender would make it much easier.

rhlvr1 · 03-19-2014, 04:02 AM

See if you can reach around the outer tire and tighten the valve extensions. I have had the same "no reading, will not take air" phenomina that makes you scratch your head. Stopped at two tire shops while traveling to Fl. this year and both shops said the inner extensions loosen and fail from the tires spinning. There must be a cure out there, but I have not investigated yet.

Ed-Sommers · 03-19-2014, 09:26 AM

Purchase and have installed Dually Valves and your life will get very easier Duallyvalve Parts & Accessories

Ed

macraekw · 03-19-2014, 01:42 PM

Quote:

Originally Posted by Ed-Sommers

Purchase and have installed Dually Valves and your life will get very easier Duallyvalve Parts & Accessories

Ed

It's my understanding that Tire Pressure Monitor systems will not work with this type extension. Is that correct?

nctox · 03-19-2014, 01:47 PM

Quote:

Originally Posted by macraekw

It's my understanding that Tire Pressure Monitor systems will not work with this type extension. Is that correct?

No. If you can measure the pressure from the end of the valve stem extension, then the TPMS sensor can also.

Smitty77 · 03-19-2014, 02:16 PM

I've had good luck changing the dual's over to Crossfires. One time install, one less tire pressure monitor, and one tire valve to fill vs two. I also like what Crossfies do as far as keeping a balance of PSI between inner/outer tires.

I would check tire temps with a RF Temp gun at rest and fuel stops. The inside dauls would usually be several PSI higher than the outside. The tire temp sensors would indicate this too, but not to the same level of detail and separation. (Much of this can also be attributed to where wheel with the brake shoes are too, so it is not all tire heat build up while going down the road.)

I still check the temps with the RF Temp gun, and find the duals inside and outside are running at about the same temps, except if checking after a extended braking periods.

And on tire gauges, get a good quality one from say a truck stop (Do some searches on this board, and some of the better names will pop-up. I'm drawing a blank on the gauge we bought.) I had no problem having mine checked at our local Discount Tire shop (been going to this shop for over 25 years now). They told me the day to come in, after they had their equipment regular calibration. At true 105 PSI, my tire gauge reads 103. So I have a good baseline. After three years, I had it checked again, still about 2 PSI off.

The key is to find good equipment, have it checked at a place you trust, and then run with it.

One last note on loose braided hoses from the inside tire. Locktight(SP) might help with this for awhile too, sure won't hurt

!

Best of luck, and salute for thinking tire safety - it's all we have between our buts and the roadway!
Smitty

Best,
Smitty

Passin Thru · 03-19-2014, 02:42 PM

I'd keep a tire billy on hand and thump them once in awhile. Made mine out of a piece of sucker rod, (used in oilfiels to pull the pump on the head you see go up n down) Makes a great whhacker and if all don't sound the same, check with the gauge.

gruelens · 03-19-2014, 03:15 PM

Quote:

Originally Posted by seadogjim

Hi George,
Thanks for your reply. One of my problems is the inner duals have valve extenders(look like metal, braided) but are still rather flexible. I have a problem holding the chuck head of the tire gauge or the head for the compressor onto the valve since it'll move when you press on the chuck head. But, the one won't give me a pressure reading and doesn't seem to be accepting air flow when I try to hold the chuck of the compressor line onto it. My compressor line has a gauge and a thumb lever you have to depress to put air into the tire so you have to hold the chuck on with one hand while you watch the gauge and depress to lever with the other hand, not an easy task(at least for me). I guess the rigid metal valve extender would make it much easier.

Yes, it reads as if your setup requires 3 hands. I would suggest getting a chuck with a dual foot and no hand activated valve. That way you can support/steady the valve stem with one hand and hold the chuck with the other. You are not the only one that has issues getting a good seal when trying to inflate.

As to the "no air" passing through line, one idea would be that someone has placed balancing beads/powder in the tires and has not used the special valve stems for that application. Just an idea.

homecan1 · 03-19-2014, 04:50 PM

Check to make sure it is tight. It may also be worn or have failed. There is a pin that runs the length of the extender that actually pushes the valve stem on the tire valve. Your gauge or inflator pushes the pin and it releases the valve stem in the tire valve. The extender only carries pressure when the valve stem is pushed. If the pin doesn't line up properly or if it is not tightly attached, it may not open the valve stem on the tire and you will not get pressure in the extender. That keeps the air in the tire if the extender comes loose or fails. I had one that gave me similar problems and the end had simply worn down to the point that it would not activate the valve stem.

pocketchange · 03-19-2014, 05:52 PM

Don't forget to bring a lunch if you are not airing up with as much AP as you can find.

I'd suggest going to a truck stop and get in line at their tire rack.
These guys need to keep moving while changing tires and without
major pressure you will spend enough time to get worn out airing up. pc

lanerd · 03-19-2014, 07:40 PM

Quote:

Originally Posted by Passin Thru

I'd keep a tire billy on hand and thump them once in awhile. Made mine out of a piece of sucker rod, (used in oilfiels to pull the pump on the head you see go up n down) Makes a great whhacker and if all don't sound the same, check with the gauge.

Yeah, that works really good when you're traveling down the highway and one of your inside duals or a tire on your toad picks up a nail and starts losing air rapidly....with a mile you'll probably have a disintegrated tire that has torn loose hundreds of dollars worth of material off your coach or toad.

There just is not any substitue for a TPMS system.

As for the tire pressure gauge, I bought two identical units that were recommended (digital) and use them to get an "average" and use that as a "base line" pressure. Having exact tire pressure is redundant, as it will change just as soon as you get out on the road. A pound or two or three is not all that important. But having a base line will insure that you are gaining or losing the correct amount of pressure depending upon speed, weight, sunlight, ect.

With our previous coach and our current one, have the inner dual valve stem passed through the rim's holes and "attached" to the outer rim such that it is absolutely stationary and cannot move during travel or when trying to put air in or checking pressure.

Good luck, and hope this helps

Ron

seadogjim · 03-19-2014, 08:01 PM

Thanks to all for the great input.
Had to hit the road today so got down and looked at the "bulge" of each tire and the one I'm having a problem with looked to have about the same bulge as the others. So, drove about 100mi. and stopped to feel all tires by hand to see if the one I suspect might be low on air was hotter than the others(I know, I need a point and shoot digital temp gauge!). It wasn't, so continued down the road and stopped after 50mi. to feel all the tires and again the temp of all seemed to be equal. Drove on(total for day was 350mi.) to first overnight stop and checked all tires by hand again, all equal. So, assume the suspect tire isn't all that low on air after all and will make it home the last 150mi. no problem.
I'll check to see if the extender is loose on the valve stem causing some of the issues but think my main problem is the flexible extender on the one dually. It's just too hard to hold it and get a pressure reading with a gauge, or enable the compressor chuck to make a tight seal on it to add air to the tire. The rigid metal extenders probably would remedy the problems I've had.
As far as a TPMS, I'm reluctant to get one since so many folks who have one complain of all the false alarms they get. I know some rver's who've had a TPMS and removed it because it was more trouble than it was worth.
Is that really true, or is a TPMS a good investment?

Thanks,
Jim