The Stovebolt Site Forums The Parking Lot Big Bolts C60 tire pressures

Hi Folks,

I'm just getting ready to put my "67" C60 back on the road and I need some assistance with proper tire inflation pressure. I've looked around on the net and haven't found anything.The truck has a single rear axle w/dual wheels.First off the light weight on the previous registration was 9200 lbs. I've added approximately 500-600 lbs. to that in mounting a water tank. Load will be 2000 gal. of water @ 8.35 lbs. per gallon. Total load 16,700 lbs. Gross weight 26,550 lbs. Thanks for the help.

Pat

Tire pressure limits should be stamped on the side wall of your tires.

Unfortunately they are not.

Most 10 ply tires are around 80 psi .I would contact the manufacture of the tires for safety to really know .

Unless your tires are really old there should be markings on the sidewall about recommended cold tire pressures for either single or dual use. Generally about 80 PSI would be right for bias ply 9.00 X 20's and 10.00 X 20's. Radials of these sizes will need about 95 to 100 PSI.

Hauling 2000 gal. of water on this size of truck can be really tricky....especially when you have a partial load, lots of sloshing around. Hope you have baffles in your tank.

James

PatS;

I'm looking in my medium duty truck service manual and the pressures range from 40-115 psi depending on tire size, ply rating and the load rating. As others have said; there should be some reference data printed on the tire. If you can tell me the tire size and ply rating I can give you the psi from the manual.

SimS

As others have said, it all depends on tire size and total gross weight. If you are running 22" or larger tires most pressures are 90-110 with radial tires.

There are also different pessures depending on the load you're carrying and wether you're running single or dual. Typicaly the max pressure is lower on duals than singles.
I could be wrong (I'm known to be more and more frequently as I get older,...), but I was under the impression that DOT standads require the max pressure & load limits stamped on the sidewall. Primary reasoning, all tires are NOT rated the same regardless of size & your tires may be too weak for your max load. If you get pulled by whatever branch of your local law enforcement that handles trucks, they are gonna look at that as well as your rated gross on your registration. They see a 10Klb truck with a 2Kgal tank, little quick math, a look at your tires,... Run light tires on a heavy truck you're gonna have a light wallet in short order.
Also, just a personal opinion, but if you're running rubber that's old enough not to have those numbers on em, I'd really think twice, maybe three times, about running a capacity load on them.

I've been collecting these old trucks for over 25 years,& some had very old tires on them, & have never seen tires without a max. press. rating on the side wall.

The load ratings didn't start until probably the 70's. If they are older than that, they are too old to gross 25k+ any way. The loads you are talking about need 9.00s and 10.00s would be better if your rims are wide enough.