Trailer tire pressure?

[Brad_bb]

I've got a 2 axle tiltbed 20ft PJ trailer  that I pull with my F350.  I just got all new tires in November.  Haven't used the trailer since November and had to add some air to the tires yesterday.  On the tire it says Maintian 80psi (550kilopascales).  I'm used to tires saying max inflation psi.  My question is, should I always run these at 80?  Even for a light load?  I got them all to 75 yesterday.  Just moving some light stuff locally today. Thanks.

[YellowHammer]

The max pressure is the also the maximum load carrying capacity.  It's is also the most "bouncy" when hauling light loads and can cause damage like my aluminum tail light bracket that fell off due to bounce while on a long haul, unloaded, and when I got home, it was hanging by the wires with a fatigue crack.  Low pressures will also cause very thick sidewall tires bias ply to wear incorrectly.

Lower pressure will give a little more grip and help not smoke the tires when the inevitable hard braking situation occurs, when unloaded, even with the brake controller adjusted.

In real life, I run my bass boat slightly under rated to give a softer ride for all my electronics, my log trailer full pressure for max capacity and roll stability, and my pickup with 80 in the rear and 60 in the front, to soften the ride.

I did over inflate on a trip to the coast, about an 8 hours tow, I assume due to a bad gauge, I have no idea, and by the time I got there, one tire had blown out requiring replacing mid tow, and the other 3 had goose egged and needed replacing buy the time I limped in. A very bad day.  So now I use two air gauges to double check my pressures.  That was an expensive mistake. 

I can say I have had more explosive blowouts from max inflated tires to slightly under inflated, so will never overinflate at all, but don't worry about a few pounds under.  When the tire heats up, it will go up several psi anyway.     

[Brad_bb]

Sounds like you're saying 75 cold is ok.

[SawyerTed]

Yes, I adjust psi based on load.  But don't forget temperature caused pressure fluctuations.

Managing trailer tire pressures can be involved.  I tend to agree that slightly less pressure than max is better than starting at max psi.  Daily temperature changes, altitude changes, average daily temperature and road surface temperature all have to be considered in addition to load.

If pressures change 1 psi per 10 degrees of ambient air temperature, we could see 3-4 psi change during the day here. 

Then there is temperature related pressure change in tires running on the road.  There's another factor. 

Combine the two and there can be 10 or more psi fluctuations in the pressure. 

Some temperature change is factored into the tire design, of course. 

So I tend to manage trailer tire pressure somewhat seasonally.  More cold pressure in winter, relatively slightly less in summer.  In both cases I rarely start with less than 15% of the max pressure on the tire. 

[YellowHammer]

75 is fine, I also make sure all the tires on a trailer are the the same pressure, so run 75 on all of them, when they heat up they will be 80 or close to it anyway.  Even if I'm going to full pressure, I stop at 78 psi.



 

[TreefarmerNN]

Yes, I adjust psi based on load.  But don't forget temperature caused pressure fluctuations.

Managing trailer tire pressures can be involved.  I tend to agree that slightly less pressure than max is better than starting at max psi.  Daily temperature changes, altitude changes, average daily temperature and road surface temperature all have to be considered in addition to load.

If pressures change 1 psi per 10 degrees of ambient air temperature, we could see 3-4 psi change during the day here. 

Then there is temperature related pressure change in tires running on the road.  There's another factor. 

Combine the two and there can be 10 or more psi fluctuations in the pressure. 

Some temperature change is factored into the tire design, of course. 

So I tend to manage trailer tire pressure somewhat seasonally.  More cold pressure in winter, relatively slightly less in summer.  In both cases I rarely start with less than 15% of the max pressure on the tire.

Did you by chance mean 85% of max pressure?  15% of 80 psi would be 12 psi- almost guaranteed to ruin a tire running on the road.

[SawyerTed]

Yes, not less than 85% of max.  

[doc henderson]

probably a NC thing,    but he said "not less than 15% of the max.  so, 15% less than the max of 80%.  

[Nebraska]

I doubt any of the tire gauges I own have enough accuracy from tire to tire to be right on. I'm guessing my tire inflation strategy is more price is right like. Close enough with out going over.

 Not saying that good precise repeatable ones don't exist.  

[doc henderson]

I have dozen of the little what I call bike gauges.  I almost hate to mention the brand I use now for fillers and gauges.    I really find the combo to be great.  @YellowHammer 

[Brad_bb]

I started out with one of those Milton gage fillers Doc, but eventually it stopped reading accurately.  

I wanted something accurate and high quality.  I bought this 0-60psi Intercomp 360087 from Summit Racing that has a large dial gauge that is easy to read without reading glasses, and glows in the dark. There is soft grip around the dial too. It also has a large circular paddle to add air and a smaller relief button the back to let air out, all one hand operation.  I liked it so much I then ordered a 360088 0-100 unit.  They are $159 from Summit, not cheap but quality.

[doc henderson]

the other head is good for dual tires on my truck and gooseneck.  I think they are just over 50 bucks on amazon and also easy for us old guys to see.

[Brad_bb]

I have just the straight part but longer for the duals on my F350.  Air fitting goes right in the end of the straight part so no gauge, but the truck also reads the tire pressure on the dash.  I should not rely on there though as those sensors can fail.  I need to add a good gauge to the straight bit.  I should be able to just install it on the intercomp gauge.

[Peter Drouin]

Good tools will let you do good work.

[Resonator]

I've seen they make automatic tire inflators that will fill your tires to a desired psi. They have a handheld digital readout to accurately set when the valve stops filling. Good ones aren't cheap, but if you had multiple trailers to maintain it might be worth looking into.

[Brad_bb]

I've got 4 trailers(including the mill), 2 personal vehichles, 2 classic cars, 3 tractors and host of hay attachments with tires, 4 hay wagons, 2 other attachments with tires, and a log splitter. So, a good air gauge is worth it.

[YellowHammer]

No, two good air gauges are worth it.  

[customsawyer]

I've worn out many a tire gauge in my time. I always go back to the long old style like the tire shops use. They are designed to take the abuse that a tire shop will put it through and tend to last me the longest.

 https://www.amazon.com/sspa/click?ie=UTF8&spc=MTozNjc2ODE5ODI1NzMxNzYwOjE3Mzk3MTU2MzY6c3BfYXRmOjIwMDA3NTk5NjE3NDMyMTo6MDo6&url=%2FGODESON-Pressure-Gauge-10-150PSI-1-10kg%2Fdp%2FB08C9V8WPH%2Fref%3Dsr_1_2_sspa%3Fcrid%3DNW5TMH6EKY52%26dib%3DeyJ2IjoiMSJ9.cLf-thI140Yvgf5lJW2n_6TJHttOQOXCi_4-u9Fr8uSgbO6sCypiq8yhqy9Cjj9xlxLIBINkEzwvtM9LR_7bUJ2Pq120Tmax0Sdy5qJCE7L27vLl_1flwErKfFb3c60P-bshL0zRfVyVSnoUzAv11KwqwnSm-Tjh6ZxzSIxrHmJEI88RbI917d7PYTTlsejHWxQlkoVewfitumDYTfiySlhaygby_ew66m_RME60dHL4OZZQOidgVjvEKGeYrTiJ_hH3284nRcZHA8oHCrdQ7LU42RnkODKfclG9Us-BOOM.hLhc9o0Rgzyx9amd4vBKU8sf5TkGp5273xkqUk0G9q0%26dib_tag%3Dse%26keywords%3Dsemi%2Btruck%2Btire%2Bpressure%2Bgauge%26qid%3D1739715636%26sprefix%3Dtruck%2Btire%2Bga%252Caps%252C111%26sr%3D8-2-spons%26sp_csd%3Dd2lkZ2V0TmFtZT1zcF9hdGY%26psc%3D1

[Sixacresand]

I do not like gauges that require using two hands and getting down on my knees to read a gauge.  I rather use the old quick type where you press it down on the valve stem and lift it  up and read the results.  

[scsmith42]

For years I used the same type of gauge as what Jake recommended above, and then coupled it with one of the Lock 'n Lube air chucks. They work great.

Today I use a Milwaukee M18 portable inflator though. Coupled with an 8 AH battery it's a pleasure on trailer and vehicle tires. Simply set the desired pressure and walk away while it does its thing. I don't think that I've used my regular air gauge in 2 years other that around the tire machine.

Big loader tires with the 1/2" valve stems get a clamp on check and Jake's gauge.

[Brad_bb]

@scsmith42  Did you mean Lock N' Lube or Lock N'Flat?  Do you have a picture of the fitting you mean?  I tried searching and this was the first that came up.


 I didn't know Milwaukee had an M18 compressor.  Maybe it's pretty new?  I have the M12 compact Inflator and I can tell you with that one, you have to be careful not to overwork it.  If it gets too hot it will fail.  I was topping up a bunch of tires and mine failed.  It was still under warranty so Milwaukee replaced it (I had to bring it to and pick it up from their service center or ship it).  Now I know not to overwork it and get it hot.

[scsmith42]

@scsmith42  Did you mean Lock N' Lube or Lock N'Flat?  Do you have a picture of the fitting you mean?  I tried searching and this was the first that came up.


 I didn't know Milwaukee had an M18 compressor.  Maybe it's pretty new?  I have the M12 compact Inflator and I can tell you with that one, you have to be careful not to overwork it.  If it gets too hot it will fail.  I was topping up a bunch of tires and mine failed.  It was still under warranty so Milwaukee replaced it (I had to bring it to and pick it up from their service center or ship it).  Now I know not to overwork it and get it hot.

Brad, I meant the Lock 'nflate. It's made by the Lock n lube folks.

https://locknlube.com/products/locknflate-locking-air-chuck?ad_id=72568078424091&matchtype=e&nbt=nb%3Amicrosoft%3Ao%3A329026670%3A1161085466735430%3A72568078424091&nb_mt=e&nb_bmt=be&nb_oii=72568559979096&nb_qs=lock%20inflate&nb_fii=&nb_li_ms=&nb_lp_ms=83359&nb_pi=&nb_pc=&nb_ci=&msclkid=5036f4006c521d92f43f93c57d296358&utm_source=bing&utm_medium=cpc&utm_campaign=Brand%20Terms%20Campaign%20-%20ROAS&utm_term=lock%20inflate&utm_content=Lock%20N%20Flate

The M18 came out a year or so back. I've used it to air up semi tires to 130 psi. It is a lot more robust than the M12 model. Mine has run for 20 - 30 minutes solid airing up multiple trailer tires (customer trailers and truck tires that were way under inflated. This was obvious after setting a bundle of wood on their trailer).

[SawyerTed]

The M18 compressor with a 2 gallon tank looks like a slick little unit.   

Not a battery compressor, I have a Metabo 6 gallon pancake compressor.  It's small enough to use like a portable air tank for topping off tires.   Plugged in it's a 150 psi machine.   

More than once I've put my 3,600 watt generator in the truck and run the Metabo compressor to power air tools on job sites or to do repairs.  

[YellowHammer]

Well, looks like this topic just cost me some money...M18 compressor looks pretty sweet 

[hedgerow]

I bought the two gallon M18 compressor back in Nov when they had all the black Friday sales going on. I just bought the compressor as I have plenty of chargers and batteries. I normally run it with a 12 amp battery and it just keeps going. I have aired up a flat 18.4 x42 tractor tire with it non stop. Some times I just don't want to get the gas powered one out of the shed to do a remote tire. I have the locknflate with the digital gauge at the house in my shop and I really like it to check and air up tires while servicing them. Have several of the old style long testers in the pickups and semi trucks in case a tire needs checked. Each semi has a hose and chucks to use the truck to air up a tire if need to be.