Jet-Air-Ride Replacement Pump

[DVan]

I'm restoring a 1988 Itasca Windcruiser (~11,000# curb wt., 15,000# Max Wt.) and have an air suspension issue.


I have a leak in my Jet-Air-Ride system which I've traced to the compressor pump. The storage tank water drain was leaking and I've replaced it. Air is also leaking back through the compressor pump - in particular, one of the cylinders. I've called Air-Ride and there is no rebuild kit and that pump is no longer made. They had a replacement pump, but it was $350-$400. Could I replace the original pump with a VIAIR unit. The VIAIR 200 pump specs say it is for a 5 gal. storage tank (which is what I estimate my tank size to be):


https://www.summitracing.com/parts/var-28021/overview/


or would a different size pump be appropriate? I'm not sure what CFM capacity, or duty cycle  is needed.

[Rickf1985]

I used the Viair pump on mine, I don't remember which one but I think it was a higher CFM pump and you want the highest duty cycle you can afford basically. If the pump gives out you have only the air that is left in the suspension and that is it. As it leaks out, and it will, the rear end will just get lower and lower. So the higher the duty cycle means the better the pump. The higher the CFM rating means the less time the pump will run to fill the tank. Mine runs a good three to five minutes if it has been sitting for a while and all the air has leaked out. Keep in mind that you are not only filling the main tank but also both tanks for the bags and the bags themselves.


Somewhere on here I posted on my replacement but you would have to search to find it.

[DVan]

Rick,
I found your previous thread. You referenced a 450P (P for portable system). The difference between the 200 and 400 series seems to be ~$30 for the compressor - the 400 appears from the pictures to have larger motors. The "C" models are for storage tanks and don't include shutoff relay/sensors. The "P" models are complete systems (i.e. they have carrying bags, hoses, shutoffs, etc.). The 400 has ~50 % higher cfm than the 450 and X80 (i.e. 380, 480) models are 200 psi vs. 150psi.

[Rickf1985]

Don't pay attention to max pressure, that is a marketing tool. Max pressure is worthless when it takes an hour to get there. And you will never need 200 lbs. let alone 150 lbs. I do have a shut off relay on mine, I replaced the original one with a modern version tied in through a Bosch relay so that there are no more burned contacts or blown fuses. I actually bought two compressors and I plan to mount the second one near the front with a separate tank and have it plumbed to run the air horns but also plumbed into the main tank in the rear through a one way valve so that if there is a extra large demand for air, such as empty tank scenario, then both compressors will run and fill it quickly. The other reason is redundancy, if the main compressor in the back goes down for some reason I will not lose my suspension since the front one will take over. But with the one way valve there is no chance that the rear compressor will ever have to feed the front tank which will have the fittings for the horns, air lines to the sides for tire filling and such. I will go out and check to see which one I got tomorrow, it is too damn cold right now. I know I did not get the 100% duty cycle which I wanted because of the price but in my case it was an emergency buy so I had to get what I could afford. I am pretty sure the one I got is 60% or 75% duty cycle. I will look through my pictures tonight, I may have something in there.

[Rickf1985]

Found my old order from Amazon. I bought the Viair 40040 400C air compressor. Here are the specs, http://www.viaircorp.com/c-models/400c/.
This is only a 33% duty cycle compressor and that is probably why I bought the second one right after the first. It was quite a while ago so I didn't remember. That said it has held up but I would strongly recommend going with a heavier compressor. But note the CFM rating, that is what you want, the higher the better. Now that I have removed all of the emissions equipment from the engine I am actually watching for an engine driven compressor I can use so that it is all automatic. Engine running then you have air, and a lot of it. I might add that you do not need one with a built in shut off since the system is set up for a remote shut off already. I do recommend you upgrade to a more modern shut off and a solenoid.

[DVan]

It'd be nice if we could get feedback on what capacities, duty cycle rating are required for vehicles of our weight or used in more recent MHs. I don't need to make the front end hop up and down like a low rider ... just keep the tank full for a nice, level ride or occasionally top off tires.

It appears that the 200 series are limited to 2.5g tanks while the 300-400 series are needed for 5g tanks.

Has anyone ever hooked the front air bags up to an air tank? Mine just has a couple schrader valves under the hood that are serviced pre-drive.


Off topic: I have an air hose for filling tires in my entry step storage bin, but where do I plug it into?

[Rickf1985]

Look inside the rear bins, there is supposed to be a fitting in there somewhere. Mine does not have it but when I talked to the guy who built the system he said they were pu in all of them. I tend to doubt it because when I had the tank down there were no extra hoses. I fully plan to remove that original tank and put in a new 5 gallon Viair tank. It has more fittings and much better design. Do you have just the air ride or do you also have the park and level? If so you will want a bigger compressor because you will be using a lot of air during the leveling process. I toyed with the idea of tying in the front bags but controlling it was going to be an issue. Then I put in new, heavier springs and I no longer need the front bags.

[DVan]

I have the park and level. The Windcruiser is new to me and wondered how well it actually works as it only adjusts the rear and depends on no leaks, of which I had several in this well cared for but older coach.


How hard and expensive was upgrading the front coils?

[Rickf1985]

It wasn't all that expensive, I bought the springs from Stengel Bros., http://www.stengelbros.com/. The work was tedious and hard for me mainly because I have a very bad back. Bent over and hefting those springs into position was rough. As long as you have a solid surface to work on and a good pair of jack stands and a good floor jack and tools then it is doable at home. What is your mechanical skill level?

[DVan]

I'm fairly good mechanically - been working on cars as a hobby for 50 yrs, mostly routine stuff not requiring heavy equipment, restoring brit. sports cars, and building amateur-built aircraft. I most of the needed equipment though my floor jack more car sized.

[Schmitti]

A big action is not a rebuilding. We had no air compressor in our RV. At the front air bellows we could only change the pressure at petrol stations or workshops. That bothered me a lot. I also wanted to run a hovercraft and other things with air pressure. So I bought a similar one, like this simple double piston compressor:

https://www.ebay.de/itm/12V-Druckluft-Elektrische-Luftkompressor-Kompressor-Autokompressor-150-PSI-DT01/282753101196?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D2%26asc%3D49133%26meid%3D84c2fde22a1f468db5cdf14df6e52b44%26pid%3D100005%26rk%3D5%26rkt%3D6%26sd%3D151763997548&_trksid=p2047675.c100005.m1851



I searched for a place and connected 12V via a switch in the dashboard. By means of pressure lines I provide a 10 liter tank and at this I have provided further standard outlets:



All in all, the components cost about 100 â,¬. The bellows are now also changeable in their pressure while driving. But it should definitely be installed check valves. I installed these in front of every bellows and in front of the tank. Should a line be leaking, the RV does not fall off abruptly.

Thomas

[Rickf1985]

I'm fairly good mechanically - been working on cars as a hobby for 50 yrs, mostly routine stuff not requiring heavy equipment, restoring brit. sports cars, and building amateur-built aircraft. I most of the needed equipment though my floor jack more car sized.

You will need a good heavy duty jack to lift the motor home, I bought an air powered 12 ton bottle jack from Harbor freight and it works great. The floor jack will just be for lifting the individual suspension arms to release the pressure on the ball joints and then lowering it down to take the pressure of of the spring. So this is something you can easily do at home. And if you have worked on British cars I don't have to do any coaching on electrics for sure!   Lucas electrics, the Prince of Darkness. :)rotflmao  If you do upgrade the compressor be sure to run a new power wire to the rear, the original is probably not in the best shape and if I remember correctly it was not big enough for the load.

[Rickf1985]

Thomas, your compressor is pretty close to what we are discussing here, probably one step up. The Viair line that we are using has a line of double compressors similar to that. Here is a link to their line of compressors. I don't see the double compressor in this lineup but I have seen it before.
http://www.viaircorp.com/compressors/

[skloon]

I also wanted to run a hovercraft and other things with air pressure.

]Did something get lost in translation here ?

[DVan]

If you do upgrade the compressor be sure to run a new power wire to the rear, the original is probably not in the best shape and if I remember correctly it was not big enough for the load.

Rick,
I did end up getting the 450 ViAir pump, but am just now getting around to installing it. Unfortunately, I did not take pictures of the wiring of the pump & solenoid. Additionally, as others have mentioned, wire colors are not reliable, Not only that, the Jet Air-Ride manual diagrams don't match what's actually in my coach.


In particular, the Jet diagram only shows (3) terminals, but I mine has (4) terminals, which matches as reference link you gave in another thread for a replacement solenoid. The fourth terminal has (2) green wires on it, one of which goes into a four wire harness going back towards the front and includes the Red (to battery) and Blue (to Chassis Fuse Block). The other green I'm assuming should be to chassis ground.


I was wondering if you or someone else with a single axle P30 and Park & Level Air-Ride system could take some photos or describe which wires are connectd to what solenoid terminal and/or chassis ground.


Right now, I get the Auto/Man toggle illuminating in the "Man" position, which is per the manual and it illuminates momentarily whenever either UP/DN toggles are pushed. But no air valves activate to fill the bags. The coach is on jack stands but the chassis appears to be low enough that the bag control valves should be "requesting" a fill.


Finally, the harness coming from the cab's control box appears to be an 8-wire (22 gage) telephone or HVAC cable which uses the Blk, Pur & Wt wires per the manual and the other 5 wires are clipped off. Is this the factory cable or some replace the original with telecom cable? Technically, the wires are mostly only carrying signals from the control box, but the Purple one is carrying power to the Compressor light on the cab's control panel and the other two are carrying enough power to operate the solenoid and control toggles.

[Rickf1985]

I am pretty sure the wiring harness has been replaced, I don't remember what the wires on mine were but if they were data wires I would have immediately replaced them since there is voltage on all of the wires. The "signal" is the voltage to the corresponding solenoid so it is not like a telecom signal, it is 12 volts and has amperage with it. 16 gauge minimum. What you would be looking for is a trailer wire harness for the actuating wires and for that pump you want no smaller than 6 gauge. If I remember correctly that pump draws 25-30 amps at full load. It has been a long time since  did mine so I don't exactly remember what I did but I completely rewired the pump circuit at the back with a modern solenoid and new power wiring all the way from the front. Lately I have been having issues with it kicking out a breaker up front that I put in the feed line to the compressor when I start it after it has sat for a long time and all the air has leaked out. After the pump runs for a few minutes the breaker kicks out and then back in after it cools. This indicates to me that resistance has built up in the circuit somewhere. I need to get under there and replace all of the air lines and fix all the leaks and then my plans are to relocate the compressor to the front of the coach somewhere and that will greatly shorten the main electrical circuit and lessen the draw. I will then just run an air line back to the tank in the rear. I also plan on adding a second pump and tank plumbed into the rear system with a one way valve so that if for any reason the primary pump fails the secondary pump can take over and there will be no loss of rear suspension. This will also double the air supply for things like tires and air tools. As far as getting pictures I don't know if I will be able to do that before I go in for surgery since it just will not stop raining here. I have three weeks left and I don't want it on stands when I go in. Those controls in the back are a real nightmare to get to over top of the axle and jammed in front of the gas tank. I have a couple pics I took of that area from a while ago, I will see if they show anything.

[DVan]

That the "signal" is actual line current was what occurred to me after I hit send, but CWVR wouldn't allow me to edit my post. So, I guess I'm in for lots of wire tracing and replacement. If you can recall or find an appropriate pic, can you tell me what wires are connected to which terminal on the pump solenoid?


Moving the pump forward sounds like a very good idea to shorten its feed line - particularly for the new pump. Thanks for reminding me about its current draw. The old pump had #10 for its leads to/from the solenoid, but the main power feed lines from the front look more like #12 or even #14 - not good! So they will need replacement as well.


Sorry to hear about you needing surgery. Is it for your back? Hoping for good outcome regardless.


We had over 5" rain last week - I'm not far from the Missouri flooding. Fortunately, my farm is considerably higher (~500'). Also, I have the coach in my implement shed so I and it are reasonably protected except from cold temps in winter.


[Aside to admin: Clicking on "edit" or "quote" brings up a new window with only text in it, and I am not able to edit or add my response to the quotes text. Clicking on "reply" wings up the old style "Post reply" window.]

[Rickf1985]

I wish the surgery was on my back, this time it is for prostate cancer. Note to all you guys out there, Do NOT miss those check ups!!! I am lucky that mine was caught early but also very lucky because one year ago there were no signs at all!
As far as the wiring I will have to look back over my notes and get back to you, I am pretty sure I just went by their wiring diagram and modified it to adapt in a standard 40 amp Bosch relay. The only thing the pump needs to know is when the pressure drops and it needs to turn on and when it is time to turn off. I did that with a pressure switch wired into the hot wire of the relay trigger. The pump can be wired completely independent of the control unit, the control unit only controls the solenoids for the air bags. That is another complete nightmare. W% D:oH!

[DVan]

I wish the surgery was on my back, this time it is for prostate cancer.

Yikes! Neither type is good. Hope you got a skilled doctor. Good luck.

I just found the main in-line 20A (red wire) fuse blown and replaced it - the pump "in-use" light now illuminates (pump's not installed just yet, just put 75psi in the storage tank from external compressor), but the bags aren't inflating yet. And, as more aggravation, I've misplaced the new pump - I hate it when I can't finish a project straight through and parts & memory get scattered about. Life happens - C'est la vie. I would like to know which wires connected to/from the pump solenoid and between it, the pressure sw and the fill relays.

[Rickf1985]

Have you tried to inflate the bags on the manual setting? The automatic setting is set for the bags to be at 11 inches fro bottom plate to top plate. If they are real close to that then it will not kick in. Set it to manual and hold up on both right and left. And if the bags are flat then that 75lbs. is gone is seconds just putting a little air in the bags.

[DVan]

Tried auto and man'l. I've loosened the actuator arms in order to manually activate a fill command in the auto mode as I'm working solo. The bags have little to no air in them and the height appears to be lower than what was the normal ride height (i.e. couple inches of the inner cone showing, no cone showing currently), I'll try measuring it.

Edit: Measured 7.5" top to bottom plate while on the jack stands (just enough for me to creeper roll under/past the black tank) - so "auto" should be commanding an inflate signal. I also found the new pump - it's a 350C (20A max.) not the 450 so I should be able to use #12 wire.

I have a gauge on the tank and no manipulations have dropped the 75psi. Once it drops, I can always add more.

[Rickf1985]

Do you have a phone number I can call you on? PM it to me and I will talk you through what I did.

[DVan]

Success! Rear bags are inflated to 50 psi using external air source. Not exactly sure what did it, but I reversed the blade connectors on the pump pressure switch and tightened down the bolts holding the pump mounting "tray" and the air valve solenoid assy., which had removed to access the fuel tank mounting bolts. I guess the control grounds all go to the chassis.


Now I get to see about correcting the bad/undersized wiring, and find a suitable location for the new pump closer to the chassis battery then re-organize the air lines and associated wiring.

[Rickf1985]

 

[DVan]

Now I get to see about correcting the bad/undersized wiring, and find a suitable location for the new pump closer to the chassis battery then re-organize the air lines and associated wiring.

Now the weather has warmed up, Iââ,¬â,,¢m getting back to repairing the wiring. Can someone tell me which color wire goes to which pin on the connector plug for the Air-Ride control solenoids? The connector on the solenoid side all have black wires, and all but one wire broke off the connector going to the dashboard controller.