Front Airbags not filling at idle??

[supercub]

I start the motor home in the morning and let idle to let it warm up. The rear bags inflate to above 100PSI. The fronts only go to about 60psi. As soon as I go about 100 feet the fronts inflate to above 100PSI. Just started having this problem. I don't know if it's extra power or moving the motor home. Tomorrow, I'll try giving it a little power before moving to see what happens. Once the pressure comes up, it holds stable. Is there a sensor that might be sticking? or ?? Any help? Thanks
Brian

[WILDEBILL308]

I think Wolfe has the right idea. Your front ride height valves may be sticking.
After you move the motion of the coach loosens them up and they start working.
Bill

[supercub]

No, gauge is not sticky. The motor home is sitting low, till the pressure comes up.
Brian

[wolfe10]

mayo30 wrote:
Do people still start and let these modern diesels idle for ever thinking they are warming them up!!!Thought that stopped years ago.

NO, at least knowledgeable people do NOT.

Start the engine. After 20-30 seconds, engage high idle (around 1100 RPM).

After air pressure builds, you are "free to move around the country".

Sure, this means under light load until coolant operating temperature is reached-- like exiting CG, low speed driving. If you overnighted at a freeway entrance, yes, stay at high idle until temperature gauge is at least half way to normal operating temperature before jumping on it.

[mayo30]

Do people still start and let these modern diesels idle for ever thinking they are warming them up!!!Thought that stopped years ago.

[Dale_Traveling]

Maybe a sticky gauge if mechanical or the pressure transducer if electronic?

[wolfe10]

The RIDE HEIGHT VALVE (most coaches have one on the front axle) sends air to the air bags. The exception would be if part of your leveling system is dumping.

[supercub]

They have always filled the same amount, up to a couple of days ago. The still are the same after I drive for a 100 feet or so. I have two gauges, front and rear gauges, I assume there's two tanks.

[Trackrig]

Are the air gauges for the pressure in the front and rear air tanks or are they for the air suspension? I haven't seen gauges for telling you the pressure in the air bags - but then I certainly haven't seen every type of MH!

And then do the rear air bags fill off of the rear air tank and the front air bags fill off of the front air tank? Do both sets of air bags fill off of one tank? Do the air bags even fill off of the brake air tanks or does their air come straight from the air compressor? I ask these questions because I don't know and maybe someone with more knowledge can give an answer.

Never the less, I would expect that if the rear air tank is at 100PSI, the front should be a lot closer than 60 PSI. Every MH or truck that I've driven with air brakes always fill the tanks a lot more evenly than that. Usually the difference is only 5 - 10 PSI which just might be the gauges themselves.

Bill