Community Forums

ebprod · 07-12-2018, 01:38 PM

I have a 2001 Damon Ultrasport, Freightliner/ Cummins ISB 5.9. We are 600 miles and 10 days from home. The low air light and buzzer came on, with the gauge pegged to max. We pulled over and found nothing obvious so we continued on to find a mechanic. The gauge would randomly peg out, then instantly return to normal operation. The mechanic couldn't find anything either, so assumed it was the gauge. We disconnected the buzzer so we wouldn't have that shrieking in our ears.

Now that we are at the campground, I found that it is probably the VDU. I found the vdcrepair.pdf for repairing the cold solder joints. After looking at the VDU, I have a few questions.

First, should I even attempt to repair this now, or would I be better off waiting until I get home. My soldering skills are pretty good.

Second, how exactly are the air hoses removed? Mine looks exactly like the picture in the pdf.

Third, how is the box opened? Will I have to force it?

The box is pretty dirty, what is a good cleaner for it?

Thanks for any help.

-Joel

Skip426 · 07-12-2018, 02:37 PM

I have the repair pdf in another computer , I'll be at home with it in an hour or so , if no one else posts it in the mean time , I'll post it then .

FIRE UP · 07-12-2018, 03:21 PM

Quote:

Originally Posted by ebprod

I have a 2001 Damon Ultrasport, Freightliner/ Cummins ISB 5.9. We are 600 miles and 10 days from home. The low air light and buzzer came on, with the gauge pegged to max. We pulled over and found nothing obvious so we continued on to find a mechanic. The gauge would randomly peg out, then instantly return to normal operation. The mechanic couldn't find anything either, so assumed it was the gauge. We disconnected the buzzer so we wouldn't have that shrieking in our ears.

Now that we are at the campground, I found that it is probably the VDU. I found the vdcrepair.pdf for repairing the cold solder joints. After looking at the VDU, I have a few questions.

First, should I even attempt to repair this now, or would I be better off waiting until I get home. My soldering skills are pretty good.

Second, how exactly are the air hoses removed? Mine looks exactly like the picture in the pdf.

Third, how is the box opened? Will I have to force it?

The box is pretty dirty, what is a good cleaner for it?

Thanks for any help.

-Joel

Hey Joe,
When Skip get's back he'll help you with part of your issue I cannot. But, in the mean time, based on the picture I'm seeing, it appears your air hoses are attached via the same way they're attached in a zillion other applications. And that is what's called "Push to connect". The hose is held in place by two things. Pressure is one and a barbed collar is another. There is a fitting that is screwed into the housing of the VDU. And, inside that fitting is a barbed collar. That collar is movable.

Here's how you remove the hose. First, bleed every pound of pressure out of your air system. Do this by pumping the brakes, pulling on the lanyard s in the front right fender well etc. When you are sure all air is expelled from the system, then, grab the air hose, about an inch or so away from that collar and push the hose towards the VDU with a tad bit of force. Then, while holding that pressure on that hose, using your other hand, push the collar, ALSO towards the VDC. What that does is, by pushing the hose towards the VDC, you're in effect releasing the bite on it, from the collar. And, by pushing the collar forward too, you're relieving it of it's bite. Now, while holding the collar in towards the VDC, you can now simply PULL the hose out of the fitting, done.

It takes a whole lot longer to explain this, than it does to do it. Let us know how you do here. By the way, if and when you're done with your re-soldering job and are ready to put it all back together, simply push the hose into the fitting. No need to even touch the collar. The hose will self bind, once it's in it's proper place and in the proper distance.
Scott

Skip426 · 07-12-2018, 03:30 PM

Back from Dr's office in record time .

Here are the pdfs . Repair and gauge testing , just in case you need it.

ebprod · 07-12-2018, 04:37 PM

Skip, Scott,

Thanks for the very useful information. I already had the repair guide, but I didn't have the technical document.

I still haven't decided if I should try to fix this before we leave camp. I would hate to do something stupid and leave us stranded.

The box is very grimy. Would it be ok to spray it with simple green?

-Joel

Hooligan · 07-12-2018, 06:38 PM

If rig is operable except for air gauge it may be prudent to get home or to a dealer with a VDU available before tempting the repair gremlins.

The cover is sealed with a rubber compound and can carefully be cut & pried off. It needs to be resealed after repair and RTV IS NOT recommended. Cleaning with simple green should not be a problem. Best to clean before removing cables/ air hoses. Or tape up to keep water out of transducers/sockets.

I have not worked on the VDU, but did have a problem with VIM-V on my 2000 Freightliner XCS chassis --Luckily my Transmission computer, VDC and VIM were located inside the right rear storage compartment, out of the weather.

winniman · 07-12-2018, 07:14 PM

We did the repair on my 2000 freightliner. It was fairly easy. My mechanic friend did the work for me after I found the info on this forum. The Rv had the problem when I bought it, and the previous owner had driven it for quite some time, perhaps years with the guages not working correctly. If I remember correctly, we just pried the box open, resoldered the joints as per the instructions, and resealed the box with dicor caulking. I think the instructions recommended the dicor, which I had in stock. Im sure it said not to use silicone. If it was me, I would wait until you got home, that way you dont end up stranded. Dont forget to reconnect the low air alarm, as it is very important safety feature. Another thing we learned in the process, is that the alarm buzzer is not only for the low air, but also acts as the alarm for many other warnings on your dash. Good luck, mine has been two years since we resoldered it with no problems so far. {knocking on wood ]

ebprod · 07-15-2018, 09:10 PM

The repair is finished. Thanks to all the advice, it was fairly simple. The hardest part was getting the air hoses off. Scott instructions were perfect, but I still had a long reach through the bed to get to them. After that, everything went exactly like the repair.pdf said it would.

We are still camping, so I haven't taken it on the road yet. We did fire up the engine and both gauges went right up to 120psi. The alarm quit when it reached 60psi. I left it running for a few minutes to make sure it would hold, but it appears to be in good shape.

Again, thanks for all the help

-Joel

ebprod · 08-27-2018, 09:47 PM

I need to update this thread. My repair didn't work, and the gauges started acting up within a few miles. I made a second try at the repair which didn't work either.

The solution was a new VDC. I got the replacement directly from Freightliner through a local repair facility. The cost was right around $400.00.

-Joel

ScoobyDoo · 08-28-2018, 07:00 AM

I had a smile reading this thread. Disconnect low air pressure warning? Violation of federal regulations to drive on street. But that safety reg does not apply to me, and I know it doesn't work, so I can just watch the gauge close. But wait! That doesn't work either...
BUT I CAN'T INTERRUPT MY TRIP FOR SOME SILLY LITTLE SAFETY DEVICE!

Hit_the_Rhod · 08-28-2018, 07:32 AM

Quote:

Originally Posted by ebprod

I need to update this thread. My repair didn't work, and the gauges started acting up within a few miles. I made a second try at the repair which didn't work either.

The solution was a new VDC. I got the replacement directly from Freightliner through a local repair facility. The cost was right around $400.00.

-Joel

Joel,

Our experience was the same as yours, our gauges would fluctuate WILDLY from 0 to max a few times, alarm would trigger, and then generally drop to zero for a time, then everything would go back to normal for a few minutes, a few hours, or perhaps days.

We do did the repair and found the instructions to be exceptionally well written and easy to follow . . . . however we to found that it didn't correct the issue and ended up replacing the VDU shortly after. Cost about the same directly from Freightliner. The parts guy said they had the part in stock and sold a lot of them

. Gee, I wonder why?

rrtribble · 08-28-2018, 09:06 AM

Joe,
Appreciate your post as I am creating a repair file for my '07 Itasca Meridian 34H. Copied your .pdf file but would like to know where the VDU is located so I can file it. You said something about through your bed. Did you mean you sleeping bed?

Thanks for info in advance and glad you got it repaired. Richard

ebprod · 08-28-2018, 11:58 AM

Richard,

Mine was located under the bed, in the bedroom. After lifting the hatch covering the engine, it was right along the wall by the foot of the bed. It was within pretty easy reach. Yours might be somewhere different, but I would start looking there.

-Joel

Quote:

Originally Posted by rrtribble

Joe,
Appreciate your post as I am creating a repair file for my '07 Itasca Meridian 34H. Copied your .pdf file but would like to know where the VDU is located so I can file it. You said something about through your bed. Did you mean you sleeping bed?

Thanks for info in advance and glad you got it repaired. Richard

Skip426 · 08-28-2018, 09:58 PM

Quote:

Originally Posted by rrtribble

Joe,
Appreciate your post as I am creating a repair file for my '07 Itasca Meridian 34H. Copied your .pdf file but would like to know where the VDU is located so I can file it. You said something about through your bed. Did you mean you sleeping bed?

Thanks for info in advance and glad you got it repaired. Richard

The gauge system changed in 04 ? ( to MMDC ) and again in 07.? ( to LBCU )

So info on the VDC repair won't help with your chassis.

RV Tech Library - Freightliner MMDC Information Display

Contact Freightliner and inquire about joining DTND Connect ( Daimler Trucks North America Connect ) for wiring and parts info linked to your chassis serial number.
1-800-385-4357 Have your serial number handy.