question on air in tires

[Ray]

Bill - Do you run 75 psi based on the load chart for cold? or do you adjust, or lower the cold psi from the chart based on the fact they will heat up and increase in pressure?

[bfadmin]

Ray,

The inflation charts for all brands of tires assume the air pressure you should inflate the tires to are with the tires at stabilized ambient temperatures and have not been running down the road. The tire pressure increase (due to heat buildup in the tire) that occurs from running the tires on the road has been considered by the tire engineers when they specify the initial cold tire inflation pressure.

bfadmin-2

[Ray]

Thats what I figured but wanted to double check on how you do it - thanks - appreciate your time and experiance

[Vlamgat]

I have the Pressure Pro on my trailer but have yet to put them on the coach. Waiting for another excuse to demount the tires to do the install as jacking one of these babies is not a casual endeavor. You dont specify the rear weight of your coach so I cant relate to the 75 psi you use. My tires are G rated so the weight of the coach is proportional to the temperature adjusted maximum load and inflation level of 110 psi. Initially I miscalculated and came up with a "safety" number of 98 psi. The ride was horrible on the interstate or any thing that passes as a highway these days. After doing the math correctly I was able to bring that down to 86 psi substantially changing the ride. But I have no idea what the pressure/temp spread is without sensors.

[whemme]

Vlamgat,

The Pressure Pro sensors just screw onto each tire valve stem. Please explain why you would need to demount the tire from the rim in order to install your Pressure Pro sensors.

[Vlamgat]

I have dual Rear Wheel set up on my Triumph. The inner wheel valves are not reachable for a Pressure Pro install. Plus the valve stems are steel bu the Pressure Pro fastener is brass which causes a metal to metal corrosion. So the coach valve has to be very carefully coated during the install.

[Ray]

Metal to metal corrosion? Brass on steel?

[Ray]

Valmgat

Did your pressure pro come with some silicon grease or similar? - Nothing came with my pressure monitor system and there was no mention of it either.

I didnt give it a thought - I am not sure if my stems are steel or plated brass. Guess I need to get the magnet out.

[whemme]

I have dual Rear Wheel set up on my Triumph. The inner wheel valves are not reachable for a Pressure Pro install. Plus the valve stems are steel bu the Pressure Pro fastener is brass which causes a metal to metal corrosion. So the coach valve has to be very carefully coated during the install.

I still don't understand how you would need to demount your tires from the rims in order to screw the Pressure Pro sensors onto the valve stems. If the valve stems for your inside rear duals are not reachable to screw on the Pressure Pro sensors, how are you able to access the valve stems with a tire pressure gauge to measure tire pressure or an air hose to inflate those inside tires?

As far as the dissimilar brass to steel corrosion issue, the Dually Valve custom metal valve stems from Borg Tire that I have used on my Born Free coach for more than 5 years are chrome plated brass so corrosion has not been an issue for me. These special valve stems are available from two different sources that I know about. You can review my post titled Chrome Metal Valve Stems for your Born Free Wheels in the Coach Modifications section of this forum to review the available custom metal valve stems.

[Vlamgat]

Oops - misunderstanding. I meant I had to dismount the outer WHEEL, not the tire. 10 tight lugs plus jacking the thing. Got to do it but in the 100 deg of our TX summer, not something I am volunteering to do.

And nothing included with my Pressure Pro kit but there is a warning in the Owners Manual about the risks of dissimilar valve metals. I ignored it and struggled to remove the sensor from my Sportsmobile Alcoa wheels. Thanks for the Chrome plate url...thats what I need to do. Puting anti-sieze on the valve stems is a delicate job as you cannot allow any to enter the valve stem or the sensor.