Air Leveling and Air Tank Pressure

[Mike Canter]

A few months ago I posted on how if I leveled my Signature with the HWH Leveling system using manual mode how it dropped on the drivers side over night. Also the tank pressure dropped pretty fast. I put big wooden pilings under the motorhome, four in the back and two in the front and I raised it up high so it was all under pressure and started at one end and sprayed all the air fittings with a soapy solution. First two things I found leaking was the bottom drain fitting on the tank. Just had to tighten that, then found the small brass blow off pressure valve leaking on the back of the tank on the passenger side. Bought a replacement through NAPA and fixed that. Then I sprayed the air solenoids that control the air bags. There are six solenoids for each axle so with a tag axle I have 18 of these solenoids. Many people call these six packs. Each six pack is divided up into the left and right side. The bottom solenoids release air out of the bags in the leveling mode, the two center solenoids are used in the Travel Mode and the two top solenoids are for putting air into the bags in the leveling mode. Well I had three solenoids leaking and bubbling up a storm for the front axle and three leaking for the drive axle. So 6 of the 18 were bubbling. Dumped all the air out of the system and took all the solenoids out. Then I built a test block that simulated being in the motorhome and put air into them. Well the were leaking from a place in the middle of the solenoid where they come apart and not from were they attached to the manifold. Each solenoid has three orings, two on the bottom and one inside. It was the one inside. Called HWH and they sell only the bottom two orings but not the one inside. They wanted me to buy all new solenoids at $110 each. My guess was that all 18 needed to be fixed. I happen to have a special wrench to take these solenoids apart and I found the inside oring hard and brittle and was causing the leak. Bought orings for 18 solenoids for $24. Replaced all three in each solenoid and tested them and installed them all back in the motorhome. So far the motohome has been sitting level in manual mode for four days without moving a fraction of an inch. My air tanks have so far maintained pressure for three days. All looks good but still testing. Based on finding these problems and fixing them and seeing the results the answer to the question should the air tanks stay pressured for two to three days the answer is YES, and should the mh remain level in storage for a long period the answer is YES. If your MH doesn't do either then you have air leaks.

NOTE, Getting under this 43,000 lb motorhome is tricky especially if you dump all the air out of the tanks and bags. Blocking up the front is easy but the weight of the diesel motor and transmission required me to put 3/8 steel plates on top of the blocks to stop the MH from sinking into the wood. I used 10X10 pine blocks for the pilings. Two pilings in the back is not enough, I had to use four to support all that weight for a total of six pilings. I also bought 2x12 boards and staggered them under the wheels so I could drive the MH up on four of them under each wheel. This alone raised it up almost 8 inches. Then I raised the bags all the way up and put the pilings under the main frame. (Not the suspension) Then let the air out so it settled on the blocks. Then I let it sit for two days to make sure it would hold before I got under it. These six packs are way up inside over the axles.

[SteveSkinner]

I'm glad you got it sorted.
I wish I had the time to do the same to my MH.
Mine sags slightly to the drivers side on the rear and the front seems to keep re- leveling everv few hours.
Generally I can only tell the rear is off level by the way the bathroom door swings, and the front - I checked it with a tape measure over a 12 hr period - moved up and down 2" quite a few times.
You certainly went to a lot of trouble and effort to solve this problem. Hate to think what it would have cost in a shop.
Hope to catch up late August if you are around

[Mike Canter]

I have the time between races. What slowed me down was all the spring rain. It didnt take that long to actually do it when i finally got to it. The solenoids used are the same used in nitrous systems on race cars. Didnt know it at the time but the guy that owns the company that makes the solenoids is a fellow drag racer. He said he has zero feedback from HWH that they have any problems with that inside oring. This is because they make people buy whole new splenoids. I should be here in August.

[Les Stallings]

Hey Mike, would you mind sharing the source and part number for the O-rings?

[Jobert]

Yes, please share the source and number for the o-rings. I have an 06 Dynasty with the identical symptoms, and am going to start investigating it next week, to at least pinpoint the leaks. Great explanation on how you went about locating the leaks.

I just did not change my Sig yet. Happy Trails Bert

[Mike Canter]

Like I said there are three orings. The small one on the bottom is a -015, the large one on the bottom is a -028 and the one inside the solenoid is a -019. I used Viton orings but since it is just air you could use any type. These oring sizes are not available at Home Depot or auto parts stores. You can look in the yellow pages seals and packing or go on the internet. The O-ring Store - Online distributor of O-rings, Seals, and Kits!, We make placing your o-ring order and getting your o-rings online easy!

I used silicone lubricant on all the orings. I also scrupped the six pack monting face with Scotch pads then blew out all the holes with air. When you take the solenoids off you can leave the electromagnet part attached to the MH. Just take the nut off the top and slide the magnet off leaving just the solenoid on the manifold. The hardest thing will be getting the solenoid apart because you cannot grab the tower with pliers and take it apart. What you need is a pin wrench or a special tool we use.
NOS 16666 NOS Nitrous Solenoid Wrench

Make sure you mark all the electromagnets before you remove them from the solenoids. It is real important that they go back the same position.

The pressure release valve on the back of the air tank is a Haldex KN31200. These valves all release at 150 psi. Monaco use a 1/4" NPT thread.

[Les Stallings]

I looked pretty hard and never found the -028 size...

Is there a different source for that size?? Thanks!

[Twomed]

Great write up Mike. Thanks.

[djhinds]

Mike. funny you mentioned the blow off valve, I found mine leaking last week and changed it with the same one from NAPA. It seams everything you have go wrong with your coach sooner or later I have the same problem. I hope I don't have the solenoid problem next....... Now my coach drops to 60lbs in about 5/6 days and then stays there for weeks. I guess I can live with that. Since my coach follows yours I hope you suddenly start getting 9 mpg..

Dave

[Mike Canter]

Les, I had no problem finding the -028
try here 028 V90 Black Viton O-ring [V90028] : The O-ring Store - Online distributor of O-rings, Seals, and Kits!, We make placing your o-ring order and getting your o-rings online easy!

Dave, I hope I start getting 9 mpg also. Try this on your level system. Raise the whole motorhome up using the bags then hit the emergency shutoff button on the leveling panel and let it sit and see what happens. I used a tape measure and recorded the height from all four corner fender wells then watched it to see if a corner drops.

[djhinds]

Mike I will do the leveling test when we get home. We are in Gillette WY. at the FMCA rally then on to Yellowstone. Will be home around the 4th. Will let you know the results then.

Dave

[Les Stallings]

Originally Posted by Mike Canter

Les, I had no problem finding the -028
try here 028 V90 Black Viton O-ring [V90028] : The O-ring Store - Online distributor of O-rings, Seals, and Kits!, We make placing your o-ring order and getting your o-rings online easy!

Dummy me, I did not go to Page 2....

Thanks again!

[Radarman]

Great writeup Mike.

[DonGott]

Thanks Mike for putting all of that info out there. That's got to be the best "HOW TO REPAIR" post I've ever read. I've got a 42' Sig that is having the same symptoms. Now I know what I have to do ................thanks