5th Wheel Pressure Gauge

Varies on every truck, my Pete 34k is 75lbs

 

Care to explain to me why I have 2 trailers with the same suspension setup and one trailer is legal at 90-92psig and the other is legal at 80psig if that's the case? Also care to explain why the T600 I drove was legal at 70psig and my pete is legal at 60psig? Or why my buddies classic is legal at nearly 80psig on his tractor and if his trailer reads above about 75 he's over?

The only way to actually know exactly where the gauge is legal is to roll over a cat scale grossed out, slide everything so you're 12 on the steer 34 on the drives and trailer and then dump the bags and refill them then mark your reading that is the only way to know exactly what is legal on that truck. Even then that gauge will only read correctly when it's on perfectly level ground.

 

I usually inflate my 5th wheel to 90 psi, same as I do my other wheels.

 

This. Take it from a guy (me) that uses these gauges daily to load and unload. Each truck can be different, even if it's the same type of truck.

The Volvo I used to drive was loaded at about 53 psi.
The Volvo I drove before that one needed 55-56 psi to be loaded.
The W9 I currently drive needs to show about 65 psi, but it has the 8-bag suspension, unlike the Volvos.

And level ground is a must.

We load our pneumatics with a gauge on the trailer and also the tractor gauge. If it's not quite level, I can still load it dang close by adding to one gauge and subtracting from the other.

We haul sand, and we never axle weigh. Just scale out (gross), get BOL, and head out. But if a fella has a tractor gauge AND a trailer gauge, he can load that wagon right just about every time.

 

Axle setup ..
Diff airbulks / age ofbthe bulks
diff mounting
Diff psi for the 34klb.?

 

Roger the "level ground is a must". I chuckle when I occasionally see one "weighing" on a slant of any degrees. If your truck will roll with no brakes, your weight distribution will not be equal/right and the number displayed is going to be meaningless.

 

You do have to be on level ground or some weight will be shifted to either the steers or trailer. As far as air pressure, it will be the same no matter what vehicle. It does not change. It's a standard of measurement that does not change. A scale uses either air pressure or a resistor made out of wire. As the wire bends under the weight it's resistance changes and weight can be calculated. That's how the in road scales work as you drive.

I'm a software engineer and made my own scale for my truck. Hung up my keys a few months ago and back working in the lab.

 

Oh, and yes, 60 to 61 is a good rule of thumb for the drives.

 

Not true, explain to me how on my trailer I have a right weigh scale it says for example I have 55,000 days n the trailer, (I don't have a pressure gauge so I don't know the psi) I have an adjustable leveling valve that you just pull a pin and move it up or down to control the ride height of the trailer. If I move it up to raise the trailer for more ground clearance my right weigh says I have more weight because it takes more air pressure in the bags to achieve that height, but in reality I still have 55,000 on the trailer. There are WAY to many variables to make such a blanket statement. That's why scales need to be calibrated for each vehicle to be accurate.

 

Not to mention the fact that readings vary from gauge to gauge. I've had three different gauges on the trailer I currently pull (lease roads aren't kind to equipment), and each one has read differently.