View Full Version : Gauges on tire inflation compressors and kits

Stephen Tashiro
11-14-2014, 3:35 AM
I have an old, loud tire inflation air compressor from Sears that has a pressure gauge with a dial large enough to be readable to the nearest pound. When I look at the current generation of not-so-loud tire inflation equipment, the gauges all have small dials. It's hard to read them even to the nearest 2 pounds. Also when I look at "tire inflation kits" for general purpose air compressors, they also ofter gauges with small dials. What explains this trend? Is it best just to over inflate the tires and read the pressure with a stick type gauge as you gradually let air out?

Matt Day
11-14-2014, 4:36 AM
Most auto parts stores sell nicer pressure gauges, with bigger faces, that have a bleed valve on them to let out air to get to the desired pressure. I'd get one of those if you're converned about accuracy, but personally I'm okay with my tired being within a couple pounds. I Usually use those little cheap pressure gauges where the stick comes out, along with my air compressor to inflate or top off tires. I'm not sure what kind of kits your referring to, unless it's the emergency inflation kits kept in the trunk.

Curt Harms
11-14-2014, 9:07 AM
I don't have a lot of confidence in the cheap stick types. I have a dial gauge that tracks pretty close to the shop that does our auto work. He's a fusspot so I expect he has an accurate pressure gauge.

Steve Rozmiarek
11-14-2014, 9:23 AM
Different gauges for different things. For example, in my younger drag racing days, a 30 pound range dial gauge was used with the slick tires. A pound off there makes a big difference, and you are working in the 10 to 15 pound range. We use the same thing for tractor tire, for the same reason. On car tires that run 30 to 50 psi, a stick gauge is more maneuverable, and as a couple of pounds off makes little difference. Good stick gauges are as accurate as a dial too, but you must buy quality. Trucks, that run duals in the 100 psi range are nearly impossible to check with anything other then a heavy duty stick gauge.

As for the gauge size on the compressors, thats for cheap. Of course you can change the gauge to one you like better. A good 3" oil filled wica gauge is pretty hard to beat.

Brad Schafer
11-14-2014, 9:52 AM
oddly, i just ran into something similar during a shop clean-up. i must have had 7 stick gauges and a couple of dial gauges, plus a nicer dual chuck inflator. since i needed to air up the dump truck tires, i tried 'em all - before and after. i used the gauge on the chuck inflator as a baseline.

none of the stick gauges were accurate within 5 lbs - in fact,a couple were off by double digits. 1 newer dial gauge was good, but the old (preferred) one was off by 15 lbs - all over the map. turns out a small spider had gotten inside it and the web ruined the accuracy.

all sticks got pitched, as did the spider gauge.

agree with former statements about dials and quality, not so much about a few lbs not mattering (at least for the dump truck). a few lbs short can mean a lot of excess heat.

Bill Huber
11-14-2014, 10:07 AM
I have an Accutire MS-435B digital one that states in the manual that it is accurate to .05 lb and reads from 5 to 99 lb.

The main reason I got that one is so my wife can check the pressure, it is easy to use and press on the tire stem.

The dial type gauges are really nice and I have one of those that I have had for years, to me the thing you want is one with a hold valve on it, makes it much easier to read.

Brian Elfert
11-14-2014, 12:23 PM
Milton still makes air gauges in the USA as far as I know. That is what I use. I guess I never was all that concerned about being a pound or two off. I don't have a known good gauge to compare against anyhow.

Myk Rian
11-14-2014, 12:29 PM
Milton is the one to get. Yep. USA made.

Grant Wilkinson
11-14-2014, 12:35 PM
I replaced the smalll dial one on my compressor with a bigger faced one.

Just out of curiousity, when you say that you have some that are off, what are you comparing them to? If you have several, and they read differently, how do you know which is right? My car has the TPMS sensors and they always read a bit off from my gauge. I don't know if the sensors are off or the gauge is.

Bruce Page
11-14-2014, 1:34 PM
I just bought one of these a month ago: Amflo 150 (http://www.amazon.com/gp/product/B000HI4J5W/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1)
It's old school, accurate, and easy to use.

Myk Rian
11-14-2014, 1:41 PM
And a similar Milton.

Tom M King
11-14-2014, 3:25 PM
Be careful if you check the pressure on a tire with fix-a-flat in it. It can fix the gauge too. On the truck and trailer with 80 psi tires, I use a hammer.

Stephen Tashiro
11-14-2014, 7:30 PM
I'm not sure what kind of kits your referring to, unless it's the emergency inflation kits kept in the trunk.

I mean a kit of attachments that fit on an air hose - a tube with a pressurge gauge on it and a fitting that mates to the valve on the tire on its end.

The fitting that attaches to the valve stem remains a mystery to me. It seems the good way for it to work would be that you put it on snugly without releasing any air from the tire, then you flip the lever on it which extends the little rod that presses open the valve on the tire. However, I never manage to do that. When I flip the lever back the air doesn't stop coming out of the tire and I have to quickly yank the fitting off the valve stem.

Tom M King
11-14-2014, 7:49 PM
And a similar Milton.

That's the one I use. One I had for a long time was plugged up when I did someone a favor, and it turned out their tire had fix-a-flat in it. It permanently stuck the gauge, and the new one I bought as a replacement is not nearly as nicely made-probably made in CHina now.

Steve Rozmiarek
11-14-2014, 8:45 PM
Milton is the one to get. Yep. USA made.

Yep, I sure agree.