Community Forums

Timjoe · 11-06-2013, 04:56 AM

My front air pressure gauge on my 2002 Freightliner intermittently just stays at zero. The low air alarm does turn off and the brakes function. This makes me think the air sensor is working, but the gauge is failing. I am assuming this to be a minor problem and am still driving the coach. Should I be more concerned?

TN-Traveler · 11-06-2013, 06:43 PM

I had the same problem with my Spartan chassis. To check it out I switch the wiring on the gages and found that the problem gage worked ok. I found that the air pressure regulate was located under the floor pan under the brake. Found 2 items looking a like and upon checking found that the air line on one air press was broken. Upon removing found that unit was corroded. Took to NAPA and they were able to match it. I found that NAPA was able to find most of my parts that I needed for my motorhome. Don't forget that most of the items are used in trucks. Happy fixing

stuhly · 11-06-2013, 07:20 PM

Just remember to use air equip fittings.

stink · 11-07-2013, 01:53 AM

you have whats called a "vdc" this sends a serial data stream to your inst panel. The vdc box is black in color and has one or two wiring plugs and two small air lines. My box is in the storage bin just aft of the rt rear wheels. The vdc boxes had a problem with solder joints going bad that will give erratic or no readings to some guages, usually intermittent. You might find this box and check the air lines to it as the air lines lead to air pressure sensors in the box. I found mine defective when my oil pressure guage went to 0. I smaked the box while the engine was running and the guage started to work again. I then replaced the vdc box and no problems!!!!

FIRE UP · 11-07-2013, 07:53 PM

Quote:

Originally Posted by stink

you have whats called a "vdc" this sends a serial data stream to your inst panel. The vdc box is black in color and has one or two wiring plugs and two small air lines. My box is in the storage bin just aft of the rt rear wheels. The vdc boxes had a problem with solder joints going bad that will give erratic or no readings to some guages, usually intermittent. You might find this box and check the air lines to it as the air lines lead to air pressure sensors in the box. I found mine defective when my oil pressure guage went to 0. I smaked the box while the engine was running and the guage started to work again. I then replaced the vdc box and no problems!!!!

Yes,
The infamous "VDC" is widely known for those cold solder joints. There have been many threads on this. And, one of them, I'd have to dig around some to find it, is very good at an explanation of how to remove the cover of the box, get to the defective solder joints and re-solder them for a good fix. But, that's more than likely the OPs problem.
Scott

Hooligan · 11-07-2013, 10:13 PM

If it is the VDC, repair instructions can be downloaded in the "files" section on IRV2..iRV2 Forums - Files - VDU/ VDC Repair

I had a problem with gauge readings and cleaned the plugs going to the VDC with good results..

Timjoe · 11-08-2013, 02:39 AM

Thanks to ALL who replied! I am new to this site and the information is wonderful and greatly appreciated! When I get home from current trip I will check out your suggestions!

69CJ5JP · 01-30-2014, 01:40 PM

I am at the VDC box wires off . I need detail of how to remove air lines. Do they come off before the elbow? can't get any up movement on a lock collar. Unit not bin touched since new, is it frozen? should collar move up into el? I have put some serious pressure on it. All air lines I know collar moves up then pull line out
WILL
2001 Kountry Star

rgvtexan · 01-30-2014, 01:59 PM

Try pushing down on the collar and then pull on the line.

charles tuit · 02-01-2014, 08:05 AM

Bleed air out of system before trying to disconnect air. This can be done by pulling air release cables in back of passengers front wheel.

Resolder the cold joint connections and all will be fine.