[B and C]

Sorry for the long post...  I'll try to be concise.  We were at HWH to get hydraulic manifold replaced.  When getting ready to leave coach raised to ride height but while driving the air supply would slowly drop to about 70 psi and stay there.  Pulled over and coach was down in the rear... fortunately there was no dragging or tire rubbing.  I had to pump the brakes while stopped to drop pressure to 40-50 psi before it would start to build pressure. Put it on fast idle and with added throttle up to 1600 rpm the air supply would raise to 115 or so psi and coach would be back to ride height.  Called Newell and spoke to Jim Raymond who thought it was the air regulator or governor.  Nursed it to Altoona Iowa and it is now at a Detroit diesel shop to be looked at tomorrow.  Any ideas would be greatly appreciated.

Thanks

[Richard]

That very well could be a governor since you had to lower the pressure below the normal kick in to get it to build.

It should have built to 120 or so without having to rev the engine, although revving the engine will get it there faster.

Couple of watch outs. IF you had your 120V compressor on, and it’s cutoff point has been raised to 120, then it would throw off all the diagnostics. Just mentioning this because I don’t know what your normal 120V compressor runs. I would turn it off while trouble shooting to avoid confounding the diagnosis.

You were alert to catch the low pressure before you put custom grooves in your rear tires. It takes about 100 to 105 psi to float the rear end on the air bags.

If you HAVE to rev the engine to make pressure, then you either have a failing compressor or a large air leak.

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I am guessing the trip to Moscow was to address the slide creeping issue that numerous solenoid replacements did not address?

[B and C]

Thank you Richard for the great advice.  We were lucky on the tag tires not rubbing.  The 120 v compressor is set at 110 high and 85 low but it was off.  

Yes, the trip to HWH was for the slide issue which was fixed with a  new manifold.....finally.  it was our 4th time in the last 5 months.  It is a long story .  Short of it is left twice and returned in less than 24 hours bc the problem returned.  They finally had to replace a motherboard and reprogram the system bc of a wrong excess slope light and the travel mode light.  The code for an 02 is the second iteration.  They were at 5th revision when they no longer did the work for Newell.  The gentleman who wrote the code was still there.  That was fortunate for us.  Told me there were over 1200 lines of code in early 2000 iteration and there were some errors in the code that took years to understand.  I learned quite a bit about how the system functions.

[B and C]

The engine compressor issue was related to the governor. It's being replaced. Should be on our way to Miami tomorrow am.

If anyone needs engine work while traveling in Iowa, I highly recommend Interstate Power Systems in Altoona, located at exit 143 on I 80. They work on trucks and bus-type motorhomes. I found the staff and techs to be very professional and knowledgeable. Finding a good shop that will take on large motorhomes is difficult.

[Jonestead]

Good catch and glad you're finally sorted. Thanks for the info

[Richard]

Interesting comment on the code for the HWH. I have noticed wonky behavior of mine as long as I have had it. I can stop the behavior by pressing the emergency stop button on the HWH panel.

The worst is that sometimes it goes into level and travel at the same time. So if trying to raise the coach, it will let air out as fast as you put it in.

[B and C]

HWH seems to be slowly phasing out the old Newell codes. They said Newell would describe what they wanted and HWH would build the motherboard. Parts are hard to come by for the older electronic systems. They just happen to find a package of NEW early 2000 plugin processors to use on our motherboard rebuild. Didn't fix everything though, the excessive slope seems fixed but the travel mode light is intermittent at best. Mitch and John at HWH took a whole day trying different system codes to get it fixed. The code seems excessively complicated. Richard, they final changed the panel by using Cancel instead of Emergency Stop which was confusing to users they said. I know bc they traded mine out as the buttons were coming through the lexan.