[77newell]

I have used the HWH manual a lot in sorting through my system. It is very helpful conceptually but it is not always consistent with how my system is plumbed. For instance the manual shows the air supply for leveling coming from the front and rear brake tanks. On my coach all the air for the suspension system is drawn from the "supply" tank near the rear axle. The order of my solenoids differs from the manual. T he's are not huge issues if you are aware that Newell did thing a bit different from the manual on at least some coaches, and for good reason in my opinion.

[cfree3]

I am not known for tact, so please forgive me.
con
Was the coach working properly relative to leveling before you changed the HCVs?

I was taught to look for "what changed". If you wade through the posts, you changed the HCVs, then concluded they were in upside down. Then reversed them. Then you reported the driver tag won't inflate.
So it's important to know if the system was operating properly before the change. If it was, then let's go back on do some diagnostics on the HCV install.

I am confused about what you are observing. Is the problem the driver side rear will not raise? Is the problem the driver side tag will not inflate? Both?

If you look at the arm on the HCV, is it level? or pointed upward which would tell the HCV to put air in the bags?

We are trying to help, but we are limited on the full story, and you aren't answering questions about the situation that are asked. Sorry for my blunt comments, we are really really trying to help you.

OK this is the history.

Last year our rear kept dropping while parked and in auto leveling. We made an appointment at HWH to have it looked at. They replaced both raise solenoids in the rear 6 pack. Our rear end started to raise faster and would hold after that. We had also noticed and confirmed while we were at HWH that during travel our rear end was riding low. Low enough to be putting a grove in the outside of our drive tires. HWH said that was a HCV problem and they don't deal with that. We also noticed our drive air bags were cracked and needed to be replaced. We had replaced the tag air bags last summer. We made it to Wisconsin where we have been parked all summer. We put on the 4 new drive air bags and but on the two HCvs.
Now when we put it in travel the right side lifts up perfectly but the left side is not. The mud flap is still on the ground on that side and the bus is leaning. We checked the solenoid valves on the 6 pack for travel and they both click as they should when activated. The HCV on the left side appears to be working right. We have disconnected the air line out and as it sits, there is air going though it.

Also when we put the bus on manual raise the whole rear end seems to raise except the tag axle bag on the left side.

We are wondering if there could be a problem with one or both of the small solenoids that are for the tag only on that side. If the exhaust solenoid is not letting enough air through to the supply tank would that keep the that side from lifting all the way??? Can we by pass this solenoid temporarily so that we can see if that is the problem?

Thanks for any ideas.

[Chester Stone]

Why not wait until the engine can be started and sufficient air can be applied? Was the new HCVs the same model as the old with identical hose connections? My 2 cents worth.

[rheavn]

Rick,
I don't see where you posted that after changing the HCVs that the ride height was readjusted to proper ride height.  May just be an omission or I missed it in your posting.  If not the coach ride height needs readjustment to the 12" measurement---front & rear, left & right.

Also when the HCVs were installed, did you test to make sure that they were working properly---raising the rod should cause the coach to rise, lowering the ride should make the coach lower.  If this step was not done, you could have gotten a bad HCV or have the rod installed wrong. I have had bad new HCVs.

Good luck.........................

[Richard]

Does the tag bag on the driver side inflate when the coach is in travel mode? You said it does not in level mode. Just wanting to confirm.

One, you can start and run the engine without the alternator. Make sure all positive cables you have disconnected are insulated and not touching ground. Merge the battery banks. The engine will run just fine. If you are only producing 90 psi with the 120 compressor, then it may not be enough pressure to raise the left rear with the slide out. The slides being out require a lot more pressure on the left side because of the leverage of the weight. Also it does not take nearly as much pressure in the front bags as the rear to raise the coach.

Two, the reason you may be seeing different behaviors between travel and raise mode is something that HWH/Newell does with 120V pump wiring. Normally, the pump is wired through a common well pump switch that is usually set to come on at 70 psi and turn off at 90 psi. So if you are in travel mode without the engine compressor running the max pressure you will see is 90 psi. I don't think that is enough to raise the driver rear with the slide out. HOWEVER, if you put the HWH control panel in Level, and you press any button to raise the coach or it goes into Autolevel, the HWH panel activates a relay by the 120V pump that bypasses the pressure switch. It will produce up 150 psi of pressure in that mode. I know, I proved it by exploding an air bag. So, in manual you may indeed have more pressure to work with.

Will you confirm that the tag axle switch on the dash is in the middle position?

The travel solenoids may be stuck closed. There are two ways I can think off to check this. The first is mark the connectors, then unscrew the right and left solenoid assemblies from the manifold and swap them. Be aware that any air pressure in the rear bags will escape when doing this so let the coach completely down before unscrewing them from the manifold. If the problem follows the solenoid then the problem is identified.

The second way is to let the coach down. Unscrew the two airlines on the back of the manifold. Unscrew the one closest to the bulkhead first. Turn the air compressor back on. If the HCV is working then air should come out of the line you just unscrewed. If you have air at that line, then screw it back on the manifold. Unscrew the other line, the one going to the air bag tank. Air should now come out of the fitting on the manifold if the coach is in travel mode and ignition on. If it doesn't then you have a stuck solenoid valve.

As far as the two solenoid valves on the tag. Yes it is possible that something is going on there, but I would definitely eliminate the other possibilities first. Here is why. Both of those solenoids are three way. In there unactivated mode, the switch in the middle position, they are set to pass air straight through. If the reduce pressure mode is activated, then the reduce three way is changed to the alternate position which blocks the path from the drive bag air tank and opens the tag bag tank to exhaust to atmosphere. If this were the case you should be able to hear air escaping from the solenoid. If the increase pressure solenoid were stuck in the alternate position, the tag bag would inflate to the pressure supplied by the compressor.

There are a few more things to try or consider.

Is is possible that the tag bag was plumbed incorrectly when it was replaced. This history of the rear dragging is concerning.

I would also chock the coach from pancaking me, and do the following. Crawl between the drive tire and the tag tire facing the drive tire. Take a little grease or gojo and lube the knob that the lower part of the vertical HCV attaches to. You want to slide the arm off of the axle mount. With the coach in travel mode and ignition on. move the vertical arm up about 1.5 inches. That should cause air to flow into the air bags. To continue the test, move the arm down about an inch below the mount. You should immediately hear air exhausting from the HCV. I don't mean to be cavalier about being under the coach and messing with the air bags, but if you are between the tires, the coach can't sit on you.

Hope this helps, and thank you for establishing a baseline.

[rheavn]

You don't have to start the engine if you have an air source that can deliver a constant 120 psi.  If so you can connect it to the shop air port.

[cfree3]

Does the tag bag on the driver side inflate when the coach is in travel mode? You said it does not in level mode. Just wanting to confirm.

One, you can start and run the engine without the alternator. Make sure all positive cables you have disconnected are insulated and not touching ground. Merge the battery banks. The engine will run just fine. If you are only producing 90 psi with the 120 compressor, then it may not be enough pressure to raise the left rear with the slide out. The slides being out require a lot more pressure on the left side because of the leverage of the weight. Also it does not take nearly as much pressure in the front bags as the rear to raise the coach.

Two, the reason you may be seeing different behaviors between travel and raise mode is something that HWH/Newell does with 120V pump wiring. Normally, the pump is wired through a common well pump switch that is usually set to come on at 70 psi and turn off at 90 psi. So if you are in travel mode without the engine compressor running the max pressure you will see is 90 psi. I don't think that is enough to raise the driver rear with the slide out. HOWEVER, if you put the HWH control panel in Level, and you press any button to raise the coach or it goes into Autolevel, the HWH panel activates a relay by the 120V pump that bypasses the pressure switch. It will produce up 150 psi of pressure in that mode. I know, I proved it by exploding an air bag. So, in manual you may indeed have more pressure to work with.

Will you confirm that the tag axle switch on the dash is in the middle position?

The travel solenoids may be stuck closed. There are two ways I can think off to check this. The first is mark the connectors, then unscrew the right and left solenoid assemblies from the manifold and swap them. Be aware that any air pressure in the rear bags will escape when doing this so let the coach completely down before unscrewing them from the manifold. If the problem follows the solenoid then the problem is identified.

The second way is to let the coach down. Unscrew the two airlines on the back of the manifold. Unscrew the one closest to the bulkhead first. Turn the air compressor back on. If the HCV is working then air should come out of the line you just unscrewed. If you have air at that line, then screw it back on the manifold. Unscrew the other line, the one going to the air bag tank. Air should now come out of the fitting on the manifold if the coach is in travel mode and ignition on. If it doesn't then you have a stuck solenoid valve.

As far as the two solenoid valves on the tag. Yes it is possible that something is going on there, but I would definitely eliminate the other possibilities first. Here is why. Both of those solenoids are three way. In there unactivated mode, the switch in the middle position, they are set to pass air straight through. If the reduce pressure mode is activated, then the reduce three way is changed to the alternate position which blocks the path from the drive bag air tank and opens the tag bag tank to exhaust to atmosphere. If this were the case you should be able to hear air escaping from the solenoid. If the increase pressure solenoid were stuck in the alternate position, the tag bag would inflate to the pressure supplied by the compressor.

There are a few more things to try or consider.

Is is possible that the tag bag was plumbed incorrectly when it was replaced. This history of the rear dragging is concerning.

I would also chock the coach from pancaking me, and do the following. Crawl between the drive tire and the tag tire facing the drive tire. Take a little grease or gojo and lube the knob that the lower part of the vertical HCV attaches to. You want to slide the arm off of the axle mount. With the coach in travel mode and ignition on. move the vertical arm up about 1.5 inches. That should cause air to flow into the air bags. To continue the test, move the arm down about an inch below the mount. You should immediately hear air exhausting from the HCV. I don't mean to be cavalier about being under the coach and messing with the air bags, but if you are between the tires, the coach can't sit on you.

Hope this helps, and thank you for establishing a baseline.

The answer to the question is that the left tag bag does not inflate in either travel or lift mode. The left drive bags are lifting totally on lift mode but not travel mode. My question at this point is at the 6 pack, the air line going into the travel solenoid is supplied by the air coming from the HCV...correct? Then how does it leave the 6 pack?? Does it go out the lift solenoids to the supply tanks? It would help if there were directional arrows on the direction of air flow through the schematic in the various modes. Thanks.

[Richard]

The Freemans and I spoke on the phone.

To answer the specific question, the air lines on the back of the aluminum six pack plate are not directly attached to the solenoids. There is a horizontal tube drilled into the aluminum plate. The solenoids when open connect to the tube. The outer 1/4 line on the back of the six pack goes into the square tank welded in the frame. One tank for left and one for right.

The Freemans have bypassed the tag axle add and subtract three way solenoids, and connected the two tag lines together. Still no go on the driver tag bag. So tomorrow they will fit an air line directly to the tag bag and determine if if will inflate and hold air. If it does, I suggest looking very hard at the tag axle supply tank for leaks.

[Richard]

I reread some of the thread. The statement that the tag bag doesn't inflate in either travel or
Level mode says the travel solenoid is NOT the problem, since air to
Inflate the bag in level mode comes from the raise solenoid not the travel solenoid.

What happened when air was supplied directly to the tag bag?

[cfree3]

I reread some of the thread.  The statement that the tag bag doesn't inflate in either travel or
Level mode says the travel solenoid is NOT the problem, since air to
Inflate the bag in level mode comes from the raise solenoid not the travel solenoid.

What happened when air was supplied directly to the tag bag?

We apparently have two issues. Our whole rear driver's side does not inflate at all in travel mode. Flopping the travel solenoids did not make a difference which has led us to believe that our brand new HCV on that side is not working. We have a new one on the way. Personally I think our other issue that the driver side tag bag is not inflating as much as the passenger side tag bag is related to the fact that we have the driver side tag wheel off right now. If we don't have that side of the axle jacked up to be perfectly level with the other side with the wheel on it, then when in lift mode the shapes of the two tag bags could be different based on the height of the axle at the time. My husband is not agreeing with me because he insists that the axle is perfectly level right now. I think it could be off somehat. Air put directly into the bag still has it looking not as inflated as the passenger side. What are other people's thoughts on this? The tag bad does have air in it. He just doesn't think it is inflating as much as the other one. It is hard as a rock but the shape is different. We verified that the tag bags are the same.