Air Problem and Solution

[prestadude]

My wife and I traveled down to Phoenix from Sacramento last week to attend my sons graduation from ASU. On the first day about 1 hour north of Bakersfield, I noticed the supply air was dropping although the brake air was fine. The level light on the dash also came on (a thread in another post to this section). Normally both are at about 110 psi. Supply could not get above 70 and would occasionally drop down below 40 psi and the low air dash light would come on. Being so close to my first night destination in Bakersfield, I decided to nurse it along. If the air got too low, I would shift down a gear to kick up the revs and generate more air. That technique got us to the campground (River Run RV Park on Highway 58 W and 99). After some frantic phone calling I located a repair place literally 2 blocks away that would fit me in first thing the next day, Jerry and Keith's Truck and Trailer. I limped the rig over the next morning and that started looking for the leak beneath the chassis and found nothing. There was still air in the bags but the fill valves were in a position to accept air. I would run the engine to get the supply pressure up but it would leak out in a few seconds after I turned off the motor so they really didn't have time to diagnose. The head RV guy (Terry Tillman) hooked up an air pressure line to the supply chuck in the chassis battery bay and cranked up the pressure. A rush of air came from a small air drier to which a pressure gauge was attached. The plastic bowl had split open releasing so much pressure that the engine compressor could not keep up. Terry said the air bags have a safety feature that they will not accept air if the system pressure is below a set point. This helps prevent a situation where suspension robs air from the brakes. The mechanics replaced the drier and I was back on the road by 10:30 AM (at a cost of only $210). You never know what will happen on an RV trip.

[larryweikart]

I had a similar experience a few years ago, on top of a mountain just 20-30 miles east of Kingman, Az but we thought it was the engine compressor until we replaced it and it didn't change anything. So I unhooked the air suspension trailer and nursed the coach to a mechanic friend of mine who located the dryer. I don't remember a pressure gauge though. Is your air dryer located by the drivers side rear wheel? I just completed the same route last week, only I left Phoenix on Friday and traveled thru the mojave and Bakersfield on my way to my current location in Monterey.

[wallyarntzen]

I had a similar experience a few years ago, on top of a mountain just 20-30 miles east of Kingman, Az but we thought it was the engine compressor until we replaced it and it didn't change anything. So I unhooked the air suspension trailer and nursed the coach to a mechanic friend of mine who located the dryer. I don't remember a pressure gauge though. Is your air dryer located by the drivers side rear wheel? I just completed the same route last week, only I left Phoenix on Friday and traveled thru the mojave and Bakersfield on my way to my current location in Monterey.

I just took my out of the storage lot this morning after it sat for approx 12 monthes. I have been starting it up and running it every 4 weeks or so, so it was not abandoned. I drove it about 25 miles to my home to wash it and clean all of the anti freeze out of the water system and low air guage stayed on and did no go off. I called my mechanic friend who only works on Detroit engines and he said I should call Newell and see where the installed the low air switch. The air preasure stayed at 120 on both guages and every thing on the coach that is air related functioned normally.

Does anyone know where the air switch is located on the 88 coaches with the 8v92 engine.

Thanks much, Wally

[encantotom]

Hi Wally.
There are 2 low pressure switches on the parking brake valve on my 02. The parking brake next to the steering wheel. I relaxed my valve so I saw them big wonder if one of them is it. Tom

[encantotom]

Tim. You should have stopped by and said hi. Forest and cindybwere here too.

I had to replace the small air dryer filter next to my leveling six pack in the passenger side engine compartment was that the one that was broke. Tom

[prestadude]

We were in a rush getting graduation things done so could not stop by and yes, the drier next to the six pack is the one that malfunctioned.

[ccjohnson]

We had a similar problem last year. We had to rig up a temporary bypass with some pipe fittings from a hardware store in Yuma. Actually just took the drier out & went directly from 120v compressor discharge port to the air line feeding the supply system. This got us over to San Diego to a Grainger's for a replacement drier.