Another low air warning.

[Dutcstar3891]

Quote:

Originally Posted by Fred Cooper Sounds like the VDC solder joint problem that primarily affected 1999 - 2001 chassis. If you can't find the repair instructions, I have a word document that describes the repair of the VDC (VDU) using a soldering iron. I has a picture of where to look. If you need a copy, send me an email address. Fred

Hi Fred,
How can I get a copy of the soldering procedure to fix the low air pressure warning problem. I have the VDC out and open but don't know which joints to re-solder.
Thanks
Dutchstar3891

[hitechal]

Please send me a copy of the VDC and it's location. Thanks!
vagabondrver@yahoo.com

[Fred Cooper]

Quote:

Originally Posted by Dutcstar3891 Hi Fred, How can I get a copy of the soldering procedure to fix the low air pressure warning problem. I have the VDC out and open but don't know which joints to re-solder. Thanks Dutchstar3891

I sent you an email via your profile. I'll need your actual email address to be able to attach the document.

Fred

[Fred Cooper]

Quote:

Originally Posted by hitechal Please send me a copy of the VDC and it's location. Thanks! vagabondrver@yahoo.com

Sent....Fred

[J Walker]

Quote:

Originally Posted by hitechal Please send me a copy of the VDC and it's location. Thanks! vagabondrver@yahoo.com

The location is determined by the coach manufacturer. It could be in a bay or attached to the wall of the engine compartment as in the case of my MH. It is a flat item about 8" x 8" and thin. It has two air tubes connected to it and a multi pin connector.

[PaulR]

Quote:

Originally Posted by Norm4015 My brother-in-law was having the same problem with the VDC. We removed it and I resoldered the connections on the circuit board. Some of the solder joints had very very small cracks and some looked like cold solder joints. After we did the repair he has had no more problems. I have talked with several people who say this is a common problem. If you are a handy man and good with a soldering iron you can fix it for free.

I too had similar low front air pressure warnings and used your excellent repair scheme to fix the VDC on our 2001 Bounder 39z. Had no problems on the first outing and enough confidence in the repair to re-connect the warning buzzer. Have had no additional problems in the last 1100 mi. My VDC is located in an outside compartment near the engine on the left side.

[vectra96]

I recently purchased a used Discovery 2003 39S and it has been parked for about 2 weeks here in Wisconsin. started the unit up today and had low air pressure warning for about 30 minutes. Both the front and rear gauges read the same around 65 psi for most of that time. Is this an indication of this problem or something else. This is my first diesel pusher and first air brake system. I thought the front and rear air systems were separate.

[J Walker]

Quote:

Originally Posted by vectra96 I recently purchased a used Discovery 2003 39S and it has been parked for about 2 weeks here in Wisconsin. started the unit up today and had low air pressure warning for about 30 minutes. Both the front and rear gauges read the same around 65 psi for most of that time. Is this an indication of this problem or something else. This is my first diesel pusher and first air brake system. I thought the front and rear air systems were separate.

The normal air pressure is about 120 psi. The front and rear brakes operate off of separate air tanks. You need to troubleshoot. Make an independent pressure measurement and go from there. If both dash pressure gauges read the same then they are probably correct. Usually they go out one at a time.

[bigdog]

I would advise that you look under the front of your rig,behind the axle and find the air tanks and the attached relief lanyards and give them a pull and let a bunch of air out.Then start the rig up and build the pressure back up as far as it'll go. Chock the wheels,turn the engine off with the key back on,release the E brake,then do a tap test where you push the brake pedal a number of times till the E brake pops back out.That should be about 30-35#s.Then start the engine and see if the pressure builds back up to the 120# it's s'posed to read. If you have a high idle you can turn that on too. You should be at full pressure in 5-6 minutes.If not,you've got something wrong with the system
I drive a school bus and we are REQUIRED to do the tap test EVERY morning before we go out.I had a couple of guys at the last place we stayed that asked me why I did a walk around and why I did that thing with the brakes.Thjey both said that they usually just start the engine and hook up the toad and head out. They have sensors and guages to tell them if anything is wrong,so why do all the extra stuff.I asked them which way they were going when they left that AM and told them that I was glad they were going the other way..