PDA

View Full Version : Putting air in tires


TNTraveler
01-02-2010, 06:30 PM
This subject might have been posted earlier, but doing a search could not find anything. :oops:

When you check your tire pressure and you need to put 110# into the tires how do you do it? Do you have a compressor, and if so what type and what is the max PSI. If you take it to a service station, how can you tell how much air to put in since the tires are hot and they will expand? Do you wait till tires cool off? Or do you check the pressure first before going so you know how much air to put in? Example: Tire checks @ 100# you need to put in 20#, so when you get to the service this is how much air you put into the tire no matter what the gauge reads when you arrive at the station. OR is there another way??

The reason I'm asking is I have a compressor but the PSI is 120# and it takes me at least 4 hook ups that is put air in the tire then what tell compressor builds back up to 120 PSI. It takes me almost an hour to fill 6 tires. There must be another way that I'm missing. :roll:

bob3nliz
01-03-2010, 12:59 PM
I do the same thing. there must be a better way, but it probably cost a lot of money for a compressor. I will be watching to see if anyone has a answer. :) BobnLiz

11B
01-03-2010, 01:20 PM
Most any Wal Mart will do it for you or decent tire store. Usually there is no charge but I always tip the guy a 10.00 dollar bill.

TNTraveler
01-03-2010, 02:36 PM
Yes, I checked at a tire store and they will do it for free. BUT the tires will be HOT when u get there. SO how do you tell how much air to put into the tires?

nuthut
01-03-2010, 03:45 PM
Unless the tire store is just around the corner and the tires dont have a chance to build up any heat, you have to do it your self. What you describe is pretty much how I do it.

You can always try the alternate method you describe and see how it works. You may end up with 130# in the tires.

11B
01-04-2010, 09:42 AM
It would seem to me that you would want the tires to be hot so you can get a correct air pressure for when your driving down the road.

Perhaps I'm missing something but what advantage is there to adding air to a cold not expanded tire. We all know that as the tire heats the air pressure goes up. At least I thought so.......

I have a auto read out in my jeep when the tires are cold ( I live in Utah) the pressure is always lower than when they heat up.

TNTraveler
01-04-2010, 10:12 AM
You need to read the owners manual on tires. THEY are always checked when COLD. as per tire manufacture. Yes, tires heat up when moving but this build up pressure is already calculated into the cold reading. If you say your readings are low, check your tires the outside tread will be shown wear. If over inflated the inside tread will show wear.

Kenkolen
09-01-2010, 09:13 PM
So what is the solution, sounds like alot of us have the same problem.
Has anyone used the air compressor on their motorhome? Will it go up to 120 lbs?

RayChez1
09-01-2010, 09:58 PM
Most tires are stamped on the outside wall telling you how much tire pressure should be when cold and how much when hot. I have 22.5 265/75 Toyo tires on my 38' Scenic Cruiser and I found out that it rides better at 100 lbs cold. When I first bought the tires the tire place put in 120 lbs of air and I didn't like the ride. The tires felt like they were too hard. At 100 lbs it gives me a nice comfortable ride on the Neway IFS chassis.
You have to have a big compressor to put that much air on those big tires. You can't do it with one of these plug into the cigarite lighter type compressor. You have to have a good size air resvoir tank to build up pressure or else you could be there all day trying to fill up those big tires. Even most gas stations have small compressors anymore, where you put in quarters. They are for automobile tires, not big coach tires.

RayChez1
09-01-2010, 09:59 PM
Most tires are stamped on the outside wall telling you how much tire pressure should be when cold and how much when hot. I have 22.5 265/75 Toyo tires on my 38' Scenic Cruiser and I found out that it rides better at 100 lbs cold. When I first bought the tires the tire place put in 120 lbs of air and I didn't like the ride. The tires felt like they were too hard. At 100 lbs it gives me a nice comfortable ride on the Neway IFS chassis.
You have to have a big compressor to put that much air on those big tires. You can't do it with one of these plug into the cigarite lighter type compressor. You have to have a good size air resvoir tank to build up pressure or else you could be there all day trying to fill up those big tires. Even most gas stations have small compressors anymore, where you put in quarters. They are for automobile tires, not big coach tires.

RayChez1
09-01-2010, 10:03 PM
So what is the solution, sounds like alot of us have the same problem.
Has anyone used the air compressor on their motorhome? Will it go up to 120 lbs?

I have seen many RVers fill up their tires with the compressor from a diesel pusher. If they can charge your brake resvoirs up to 130 lbs, I don't see why they can't fill up a tire to within that range.

03heritagerider
09-03-2010, 02:11 PM
On my coach, there is an on-board compressor for the for the air ride system and I suppose it supplies the air brakes as well. The line runs through the front compartment where the generator is housed. I disconnected the line and added a "T", a ball valve, and a slip joint connector. I carry a 50' air hose with several attachments. One of them is an air chuck for filling tires.

Before I leave the driveway, I let the motor warm up and allow the air pressure to build. I then check the pressure on the tires and if needed, I fill them from the on-board system. It works very quickly. Rarely have I had to add more than 5-10 lbs.

Everything I have ever read, including the stamp on the tires, the stickers in the coach and on the door jamb of the car state, check air pressure when cold.

holmesaw
09-03-2010, 07:39 PM
You were speaking of pressure in the 110 lb range. I have an 05 sun voyager and carry 85 in the rear and 90 in the front as specified.
Why do you need 110 lbs?

Sundancer268
09-03-2010, 09:28 PM
It is easy to figure out how much air to add to your tires when driven to a service station. You check the pressure when cold and find out how much air you need to add. You then drive to where you will get the air from and take a new set of pressure readings and then add the pressure to this new reading from your cold reading. If you require 120# aqnd read 95 when cold, you are 25# low. When you take the hot reading and it reads 115# you add the 25# pounds to the 115# and come up with 140#, this is what you will inflate your hot tires to. When they cool down over night they will come out to 120# the next day or close enough to 120# you should not worry about it.

CraigS
09-08-2010, 09:46 PM
My portable compressor is a DeWALT D55140. It produces max pressure of 135 psi - with the motor running - which is more than enough to fill my tires. The trick with all small compressors is too keep the motor running. If it the motor stops, fill rate decreases until the tank to empties to 90 psi at which time the motor restarts. Just remember: 135 psi is available only with the motor running. I usually just pull the pressure relief valve next to the regulator to start the motor - and then run it continuously until each tire is full.

I also use a TST 507 RV TPMS and am now quite familiar with pressure changes as I drive.

I used to fill my tires to 100 psi - just to be safe. I think I loosened a few teeth along the way :D. With the TPMS, I have found that my tire pressure increases about 10% after about 20 minutes of driving. That means we traveled at 110 psi most of the time.

I have since weighed my coach and now follow Michelin's recommendations. We now start each trip at @86 psi all round. After warming up, we actually travel at about 95 psi. Much smoother ride for sure.