Dual Tire Pressure Equalization

PapaD · 09-23-2014, 09:42 PM

Greetings all, I'm a new owner of a 2013 Haulmark triple slide with a freight liner columbia 450hp MB. I have been reading about equalizing the tire pressure in the duals using like a crossfire system and was wondering if anyone on the forum uses these, had any luck with them any recommended place that might install them.
thanks PapaD

Gordy · 09-23-2014, 10:31 PM

Welcome aboard.
I looked at this system a couple of times but didn't like the cluttered look.
I hammer the tires every morning and do walk arounds during the day. Check the pressure before leaving and generally when we going to be stopped for a while.

bushpilot · 09-23-2014, 10:51 PM

Welcome to the forum PapaD !

I run the TST 507 Tire Pressure & Temperature Monitoring system - when i wanna check the tire pressure i turn the monitor on....thats it ! No more dragging out hoses or gauges or starting the truck to use the compressor.

I run sensors on the toad's tires too - the monitor on the dash displays the pressure and temp & alarms if there is excessive temperature, percentage overall or psi decreases in any time (including the toad).

hot rod · 09-23-2014, 11:35 PM

I run the tst on the triaxle trailer tires and couldn't be happier. Best money I ever spent. I figure saving two of the 16" trailer tires paid for the unit, one 22.5 on a big rig saved would pay for the unit, and that doesn't even count damage to the coach from a blown tire. Catch a slow leaker going down the road before it goes flat, blows and comes apart. All that is aside from the convenience of never having to use your tire gauge again.

PapaD · 09-23-2014, 11:41 PM

Thanks for the info guys, I have also looked at the TPMS as well and really like what I see about them. Just wondered how big a problem it is with different air pressures between the duals or was that all hot air to sell a product..

thanks PapaD

bushpilot · 09-23-2014, 11:49 PM

I caught a slow leak my left steer tire - with the TST Monitor....powered it on a couple days before a trip and discovered the tire was down to 90 psi....i pumped the tire up and came back the next day....pressure down again.

it was a bad valve stem (cracked at the base of the wheel & valve stem nut)....i believe, if anything cracked it, it was me or the guy who put the new steer tires on...the gauge i used (at the time) took quite a bit of pressure against the valve stem in order to get a reading and i likely fatigued the stem before i had the TST system.

my toad (wrangler) runs 18 inch wheels & has different pressure than the 22.5's on the coach....no problem for the TST system, different set points with different alarm set points.

i still perform VISUAL inspections of our tires when we stop or before we depart for a trip, but thats only good enough until the tire rolls (could pick up something in less than one revolution).

i know a lot of folks swear by laser thermometers - but they only work when you STOP and they don't tell you squat while you're driving (and sometimes we drive 12-16 hours straight).

bushpilot · 09-23-2014, 11:54 PM

Quote:

Originally Posted by PapaD

Thanks for the info guys, I have also looked at the TPMS as well and really like what I see about them. Just wondered how big a problem it is with different air pressures between the duals or was that all hot air to sell a product..

thanks PapaD

i set my duals to the same pressure & then monitor them individually for leaks and heat via the TST Monitor...im not sure id want a leaking tire tied to a good / non leaking tire.

of course equalizing the pressure i important - but once you're in the coach and going down the road what can you tell about the tire pressure & its equalization ? (nothing).

theres plenty of TPMS sensors - but not many that do temperature too. Lots of folks (usually the ones that don't have temp monitoring) that pressure is directly related to temperature....and those of us with the TST system can tell you thats not true - pressure increases are NOT linear to temperature increases.

temperature increase can identify an over heating axle or sticking brake....or OVER use of the brakes (in traffic).

PapaD · 09-24-2014, 11:58 AM

Thanks again for the info will be moving forward on the purchase of the tire monitoring system, appreciate the help
-------------------------
Dennis B

hot rod · 09-24-2014, 10:47 PM

I agree whole heartedely with bushpilot, the temperature function is just as important as the air pressure. You set the alarm for a drop in pressure, or an increase in temperature. Either is a sign of impending tire failure. And he is correct you will see the tire temp go up if you have a bearing or brake problem developing. I once had an emergency brake not completely release and was rubbing slightly. Ninety miles later I finally noticed when the red hot backing plate blew the seals out of the wheel cylinder, the brake fluid caught fire, and I saw flames flickering in my rearview mirror. "Luckily" it was night time or I wouldn't have seen that either. A tire monitor would have sounded as soon as it started to get hot. It used to be my habit at every stop to do a walk around, visually inspect each tire, thump it for pressure, and lay my hand on the wheel to check for anything too hot. With the tst system all I do is the walk around and visual.

It amazes me watching the readout how much the temperature changes in the tires. Pressure, outside temperature, speed, load, even which side is in sun/shade all make a noticeable difference. When I had 15" load range D tires on my trailer I was having tons of tire problems, even though when I scaled it I was within the rating of the tires. But I found that as my load got closer to that point, the tire temperature went up dramatically. And the temps went up far more than the pressure. Even a 1000# difference in the load on a triaxle trailer made a difference. Also the speed, the tires were running way hotter at 65-70 vs. 55-60. Eventually I upgraded axles and went to 17.5 tires and tire problems went away, but I learned a ton with the tst sensors on saving tires, and still run them. The 17.5's were the second best money I ever spent, in a season and a half I have literally not even had to add air to the trailer tires, the spare has never been on the ground, and I was going through 5-6 tires per season before that. I never left the shop without at least 2 spares.

While it is correct to say that the pressure needs to be the same in both dual tires, out in the real world it is not critical that they have to be precisely the same. The theory of course is that the tire with the higher pressure will have a slightly larger diameter meaning it is supporting a bit more than it's fair share of the load, and with the larger diameter the rollout is slightly bigger so the surface of that tire is travelling just a bit faster than the other tire causing faster tire wear. So, like I said out in the real world, you would have to have a pretty serious difference in the pressure for any of that theory to translate into enough reality that you'd notice. 5 or 10psi on a heavy truck tire is not going to make an appreciable difference in any of that, and you can certainly keep track of that with a set of monitors and gain all the other benefits at the same time.

PapaD · 09-24-2014, 10:52 PM

thanks Hot rod appreciate the real world info and that is the reason I joined the group. thanks and safe travels
Dennis B

Gordy · 09-26-2014, 06:30 PM

Bushpilot-did you use the flow thru sensors or did you have the tire shop re & re tires and put the internal sensors in?

Bob86ZZ4 · 09-26-2014, 07:45 PM

Welcome to TruckConversion.net! Great that you bought a truck conversion. It sounds like you're convinced on using a pressure monitor, so I don't have to push that. I've had my system for 5 years. I bought the Pressure Pro brand monitor. PressurePro - Tire Pressure Monitoring System HOME

I'm real happy with it. I pull an enclosed car trailer, two axle, and I run the pressure monitors on those tires too. This summer I had two tires fail on the trailer, on the same road trip! One of the tires blew instantly when the tread blew off. The monitor alerted right when that happened so I guess the monitor didn't help any there. The other tire began to lose pressure pretty fast before the tread blew off. It gave me enough forewarning and I slowed way down and made it to the next exit ramp and into the truck stop. Sure glad I had the monitor. Pressure Pro I think is made in the USA, I like to support USA workers/companies, and I think the quality reflects the made in USA.

Bob86ZZ4 · 09-26-2014, 07:47 PM

Pressure Pro sensors screw onto the valve stems. I also have Dyna Beads in my steers and they do not effect the Pressure Pro sensors. When I get new drives in the spring I'm going to put Dyna Beads in them.

bushpilot · 09-26-2014, 08:01 PM

Quote:

Originally Posted by Gordy

Bushpilot-did you use the flow thru sensors or did you have the tire shop re & re tires and put the internal sensors in?

I have the "cap" or spin on style sensors.
The flow thru type were not available when I purchased mine.

I went with the spin on with the user replaceable batteries - the batteries last about 15-18 months - and I've been buying 10 or 20 batteries at a time off the net for about 26-34 cents a piece (including shipping).

TST offers a "cap" style that has a non user serviceable battery (claimed to last "about" 5 years) - but they have to be returned to TST for service - iirc they charged 19 bucks (per sensor??).

hot rod · 09-28-2014, 12:36 AM

Well, I just ran into my first pressure sensor issue. I was doing maintenance on the trailer axles, (grease, check/adjust brakes, etc) and decided I'd pull the sensors and bring all the tires up to the exact pressure. I'd had the sensors on since spring 2013 and had not had to remove any to air up tires, some were down a bit on the sensors, but not enough to worry about. Anyway, the bad news is all of them are frozen to the valve stems. Tried as hard as I could with their supplied tool, nothing would budge. I guess the dissimilar materials of aluminum sensor and steel valve stems bit me. I soaked the threads in wd40 and will give it another try tomorrow, crossing fingers. So I guess the moral of the story is take the sensors off once in a while to clean the threads. Any ideas on a non-destructive way to persuade those things off?

Kenn · 09-28-2014, 02:12 AM

I have heard that 50% ATF and 50% acetone works great on rusted bolts. Might be worth a try. Good luck

bushpilot · 09-28-2014, 09:48 AM

I took the security covers off after my 1st year and never put them back - I found their tool to be a bit lacking and sloppy - so I've been using needle nose pliers or angles needle nose pliers - seem to work fine.

I guess I've been lucky - perhaps I'll put some anti seize on em when I change the batteries in the spring.

Personally I like PB Blaster - but you might wanna call TST and see what they say....and what they're willing to do if some of them break.

hot rod · 09-29-2014, 10:26 AM

Don- how did you remove the covers? Just have to break them off? Once the cover is off is there something substantial to put the pliers to, just that same flat that the tool uses, just easier to get to without the cover?

bushpilot · 09-29-2014, 10:54 AM

Quote:

Originally Posted by hot rod

Don- how did you remove the covers? Just have to break them off? Once the cover is off is there something substantial to put the pliers to, just that same flat that the tool uses, just easier to get to without the cover?

On mine there were 3 very tiny screws (on the back side) of the security covers.

I removed the security covers (after having them on over a year) because my wheel / tire stem openings had tight clearance issues with the covers on the sensors....and because i was less paranoid about theft (my sensors are barely visible w/ the security covers removed).

with the covers removed you can turn the sensor (by hand) OR you can more easily get a pair of right angled needle nose pliers on the back of the sensor (where the TST tool would go).

remember i have the sensors with the user accessible/changeable batteries - one a couple that have been "tight" coming off the valve stem - the battery access (cap) sometimes spins off before i can get the sensor off the stem/threads....so i use something similar to these - the angled needle nose pliers allows me to reach around the back of the sensor to grab the same wrench point that the TST tool mates to...

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