Community Forums

beensell · 01-05-2018, 09:09 PM

Our NTM 04 DSDP 4025 occasionally air pressure on the front gauge drops, alarms sounds, then builds back to full pressure. Is this normal or do I have a problem. Thanks

GreaTOne65 · 01-05-2018, 09:24 PM

Beensell, first best guess, the air governor. How many miles on your coach? Have you got out to see if you can hear any air leaking? Could be the air dyer, but would start at the governor. My coach started having problems keeping the air at 130 lbs. It would drop back after a stop. If I pulled into a rest stop, and flipped on the high idle it would run the pressure up, but soon after, out on the road would drop back to 90, just high enough to keep the buzzer from sounding. I didn't want to take the time to change it on the road, but at a truck stop, went in and bought a new one, just in case. Before I start back for MI. I am going to install the new one. A new one is $29 bucks, and on my coach is easy to install.

tizzyfit · 01-05-2018, 11:39 PM

Quote:

Originally Posted by beensell

Our NTM 04 DSDP 4025 occasionally air pressure on the front gauge drops, alarms sounds, then builds back to full pressure. Is this normal or do I have a problem. Thanks

I hope you don't have a problem, but you may. 2 years ago, one of my air pressure gauges was doing the same thing. My "problem" turned out to be a small hole on one of the air lines causing the engine air pump to run constantly. My gauges top out at 130 psi, the pump is capable of producing more psi than that, but you'd never know it looking at the gauges, which lead to the braided line from the pump to the air dryer developing a rather large hole. By the way, the repairs weren't that expensive, spending Labor Day weekend at a weigh station in Podunk Montana and trying to locate a mobile diesel mechanic who could address this issue turned out to be a real problem.

SteveR161 · 01-06-2018, 07:03 AM

VDC_Repair FL VDU.pdf

See if this relates to your issue. This applies to a Freightliner chassis.

beensell · 01-06-2018, 08:57 AM

Thanks for the input. I should have mentioned that this is on a Spartan and happens once every several hours or miles. No regular intervals. Only 42000 miles.