HWH Air Compressor Replacement Last Summer

[Dr4Film]

Hi Folks,

Just to close out this thread with a follow-up, some photos and description of what I did to relocate the failed air compressor for the HWH Air Leveling System.

After the complete unit was removed from under the coach where it was housed in a cage just to the rear of the front axle (VERY poor location - what were they thinking????) I removed the defective air compressor, relay and pressure switch. I then verified that the air/moisture spitter valve still worked by hooking it to a 12 VDC battery. I removed the filter above the valve and that did not need any further maintenance so I replaced it without any maintenance. I then cleaned up the base and proceeded to install the three new components.

I had previously purchased a new air compressor, Viar Model 450C, an Emerson Relay Model 120-105711 and a Viar Pressure Switch Model 90100 which is On @ 90 psi / Off @ 120 psi. All three were obtained from Amazon.

I also purchased 10 feet of 3/8 air line, one air-line union-coupling, some wire and split loom from the local NAPA store.

I extended the two wires using crimp connectors and heat shrink. I installed the air-line coupling onto the line coming from the rear of the coach that goes to the rear 6 pack valves and also hooked it to one end of the new air-line. I then removed the old short air-line coming from the front 6-pack valves and attached the other end of the new air-line to the 6-pack valve. I used spilt-loom to cover all of the wires and air-lines for protection. All of those extensions were routed through a chassis frame which went directly into the adjacent bay where the diesel fuel and LPG tanks were located and where the new location will be for the air compressor.

I had previously constructed a wooden shelf over the passenger side of the LPG tank which will hold the air compressor unit. The Viar Air Compressor came with rubber isolators but I added the springs that were used on the old Thomas Air Compressor to the mounting also. I also used some new springs between the base of the unit and the shelf to help further isolate and help dampen any vibrations coming from the compressor. I positioned the complete unit so it was easily accessible for routine maintenance if needed. Due to my installation of the compressor unit onto the wooden shelf I installed a ground wire from the metal base of the unit to the chassis to form the ground needed to run the system.

I have attached photos of the rebuilt base unit installed in its final resting place.

I am VERY pleased with the outcome and appreciate all of the help from my Workamper neighbor who was hired to do all of the work under the coach while I assisted him from outside with tools and materials.

I am now able to re-level the coach without having to start up the engine to air up the system plus I no longer will have to worry about the air compressor failing once again from exposure to the elements, road debris and whatever it was exposed to in its previous location.

[Guest Cruzbill]

Nice work! You mentioned you can now 're-level' the coach without starting up the engine air compressor. My motorhome will end up in a squat to the right rear side after a few days in the storage yard. I have no way to get under the coach to check for the obvious leak. My question is: Can I use the HWH leveling to re-air my suspension? Or would that be too much work for my original Thomas compressor? 

[georgeandlouise1]

How often does your pump come on?  Will it keep your coach level?

[Dennis H]

Originally  Monaco positioned the compressor just in front of the REAR axle. Imagine sleeping when your rig decides to relevel!!! I like the idea above the LP tank. I wonder what it would coast to have a smaller LP tank installed and free up all that space underneath to say nothing of the weight reduction.???. How did you block the coach while your neighbor was underneath?? Since mine is back by the rear axle I'm thinking I'd have to run a line all the way back there to tap into it. I can run stuff but I've seen how fast one of these drops when it loses air. I don't want to be that guy under it when/if it does...Another question is how quiet is the new compressor and it's location???....thanks for the pictures...Dennis

[Dr4Film]

20 hours ago, Cruzbill said:

Nice work! You mentioned you can now 're-level' the coach without starting up the engine air compressor. My motorhome will end up in a squat to the right rear side after a few days in the storage yard. I have no way to get under the coach to check for the obvious leak. My question is: Can I use the HWH leveling to re-air my suspension? Or would that be too much work for my original Thomas compressor? 

Yes, I do that now versus having to start the engine to build up air pressure. The HWH compressor sends air directly to the leveling air bags and not the front & rear tanks.

17 hours ago, georgeandlouise1 said:

How often does your pump come on?  Will it keep your coach level?

Since I don't leave it in AUTO mode it never comes on. I normally have to tweak the leveling in manual to get the coach level to my liking. 

16 hours ago, Executive45 said:

Originally  Monaco positioned the compressor just in front of the REAR axle. Imagine sleeping when your rig decides to relevel!!! I like the idea above the LP tank. I wonder what it would coast to have a smaller LP tank installed and free up all that space underneath to say nothing of the weight reduction.???. How did you block the coach while your neighbor was underneath?? Since mine is back by the rear axle I'm thinking I'd have to run a line all the way back there to tap into it. I can run stuff but I've seen how fast one of these drops when it loses air. I don't want to be that guy under it when/if it does...Another question is how quiet is the new compressor and it's location???....thanks for the pictures...Dennis

Since the HWH was up front I didn't have to block the coach. I simply raised the front to it's maximum with the air then held it there with the HWH. The HWH is isolated from the ride height system. The noise from the compressor is about the same as it was before in its original location. it doesn't bother me as I don't leave it in AUTO mode.

[Paul J A]

I would think a simple  4 sided enclosure around the compressor with ceiling tile would diffuse the noise. Also mount on a rubber kneeling pad would help reduce transmission.   Another member on this site installed the compressor in a basement compartment and did some sound proofing that was very effective. 

Paul A

Dennis; A few members have removed the LP tank and went with the smaller portable tanks for LP.  You have to address the various uses you have for the LP from a point of what  regulators  are needed as you did when the tank was in place..    A great storage space for long items as well as  what ever you prefer.   AS they say, " I have ideas i have not even thought of yet"

Paul A

[JJMonaco]

Did you extend the 12v wire that was the original power source.  Mine has an in line 15amp fuse.  I am wondering If I need to run a heavier gauge power wire?  In reading the specifications for the Viar 450C it shows a max 12v amp draw of 23 amps.

[Dr4Film]

6 hours ago, jjroxus said:

Did you extend the 12v wire that was the original power source.  Mine has an in line 15amp fuse.  I am wondering If I need to run a heavier gauge power wire?  In reading the specifications for the Viar 450C it shows a max 12v amp draw of 23 amps.

JJ, I had to extend the power wire and the air lines. I installed a new ground wire which is the white one in the photo. The power wire is the large red one. I used basically the same gauge wire that was there. It was originally on the other side of that wall sitting on an open platform exposed to all sorts of weather and debris.

Not worried about maximum amp draw. It really doesn't run that much. However, I want it to run when I need it to which is does.

The Viar 350C will work also which has a 20 amp draw. The 450C was a good deal at Amazon at the time, it was around $200.

[rpasetto]

6 hours ago, Dr4Film said:

JJ, I had to extend the power wire and the air lines. I installed a new ground wire which is the white one in the photo. The power wire is the large red one. I used basically the same gauge wire that was there. It was originally on the other side of that wall sitting on an open platform exposed to all sorts of weather and debris.

Not worried about maximum amp draw. It really doesn't run that much. However, I want it to run when I need it to which is does.

The Viar 350C will work also which has a 20 amp draw. The 450C was a good deal at Amazon at the time, it was around $200.

Thanks for the writeup.  Moving my aux compressor is on my 'to do list.  Mine's in the rear, on passenger side above& forward of drive axle.  Funny how Monaco always put those compressors in places where the tires could throw rocks at them.  They could have mounted them on their roadmaster chassis so they could be located in fuel tank compartment, for example.  Then again they could have relocated the 6-packs to a compartment too.  (another idea for a project) 

[JJMonaco]

Dr4Film,

Thanks for the reply.  I ordered the Viair 450c today and will follow your lead installing it.

All The Best,

JJ

 

[Jdw12345]

My only thought on why Monaco didn’t originally mount it in the fuel bay (diesel and propane) could have been in the unlikely event that the propane tank had some sort of leak and the compressor kicked in and caused a potential ignition point. I do realize that propane is heavier that air but one never knows all of the conditions that might cause a problem!
 Personally I think it should be mounted in the heated water bay with the Aqua Hot. I would think it could be easily made removable with a quick disconnect air coupling and a plug for the power supply. 
 

 

     JMO

Edited November 14, 2021 by Jdw12345

[willbo777]

6 hours ago, Jdw12345 said:

My only thought on why Monaco didn’t originally mount it in the fuel bay (diesel and propane) could have been in the unlikely event that the propane tank had some sort of leak and the compressor kicked in and caused a potential ignition point. I do realize that propane is heavier that air but one never knows all of the conditions that might cause a problem!
 Personally I think it should be mounted in the heated water bay with the Aqua Hot. I would think it could be easily made removable with a quick disconnect air coupling and a plug for the power supply. 
 

 

     JMO

That's exactly where I moved ours.

[JJMonaco]

Yes I agree - for ultimate safety the Aqua. Hot bay would be the best choice from a safety standpoint. 

Thanks,

JJ

[rpasetto]

On 11/14/2021 at 6:17 AM, Jdw12345 said:

My only thought on why Monaco didn’t originally mount it in the fuel bay (diesel and propane) could have been in the unlikely event that the propane tank had some sort of leak and the compressor kicked in and caused a potential ignition point. I do realize that propane is heavier that air but one never knows all of the conditions that might cause a problem!
 Personally I think it should be mounted in the heated water bay with the Aqua Hot. I would think it could be easily made removable with a quick disconnect air coupling and a plug for the power supply. 
 

 

     JMO

The heated water bay is a good place.  Actually the water bay in mine is closer to the rear axle.  I may have difficulty finding accessible space there though but I will take another look.

For some, the fuel/LP tank compartment is a relatively close move.  Not sure about the spark possibility with that compressor.

After crawling under my last coach to change an HWH solenoid, it occurred to me that Monaco could also have found some compartment space to put the sixpacks...  a lot of wiring and hose routing but It could be done.  Anyone see a downside to that?

[Yoaks5]

I just changed my auxiliary compressor. Looked at moving it but in the end just built a wood box around it out of scrap 1/2" osb and painted it with extra exterior house paint I had on hand. I stayed with the Thomas compressor. I don't think noise is going to be an issue since I can barely hear it in the bedroom (hope I don't have to eat these words later since we haven't slept in it since the change). The box has 4 sides and a bottom. I just got 2 longer bolts and after I bolted the compressor assemble back on added a couple washers and bolted the box to the bottom. It is open on the top but I think this will keep it much cleaner. 

[willbo777]

Looks good, but won't it fill up with water and dirt from the tire?

[Jdw12345]

Has anyone thought about mounting it in with the generator?

[Dr4Film]

22 minutes ago, Jdw12345 said:

Has anyone thought about mounting it in with the generator?

I mounted a separate small air compressor in the generator compartment to operate my front stairwell cover when parked for a long period of time.

I haven' taken any photos as yet but will today and re-post.

[Paul J A]

 This is a post from another social media site.

He bought this compressor and connected it to the quick disconnect for air in the genny compartment. Instead of rebuild/replacement of the compressor for leveling. Pretty cool. He puts it in the genny compartment when using it. Has 135 P S I. Good for tire inflation too and no running engine to get to ride height before bringing in slides. This would, could, may,  satisfy any and all needs for air when the coach engine is not running. Battery could be used for power when doing trouble shooting.

[SigPIlot]

Such great input. Used the pictures to replace pump (HWH says it wasn't there's, but an HWH pump was on backorder with no ETA in sight) I did have them rebuild the two control boxes - fast and very inexpensive. Used a Viair IG with a new solenoid and relayed pressure switch. Decided tp leave it where it was but may enclose it sometime. (It's on the todo list) Works great, especially when you fix all the air leaks and rebuild the six packs. Good for another 50K miles.

[Yoaks5]

On 11/19/2021 at 8:24 AM, willbo777 said:

Looks good, but won't it fill up with water and dirt from the tire?

I hope not. Time will tell though. I read on IRV2 about guys doing something simular with good results. I'll check it after our upcoming trip and see how it looks.