Newell Gurus

Full Version: Solenoid valve in path of rear airbag system
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On the diagram that Richard and Steve Bare put together:

There’s 2 blocks marked SV on each tag airbag circuit.

I am assuming that those are solenoid valves that arr used for the “Raise tag axle” function. Is that right?

I have a solenoid valve leaking lots of air in any mode - raise, travel or ign off. It is mounted to the frame rail on the curb side approx between the rear tires.

It leaks enough to drop the driver’s side of the coach all the way down in travel mode.

I’m assuming at this point that it is the SV on thr diagram with the exhaust port. Can anyone verify that?

Wondering if anyone has a part number. Alternately, I am assuming that if it is the exhaust valve for raising the tag that I can simply bypass it for now.
A couple of things to think about.

One, the Newell circuit does not raise the tag. The circuit and two way switch are designed to increase or decrease pressure in the tag air bags which in turn lowers weight on the drive axle or increases weight on the drive axle. The former was originally used for some toll highways that had a weight limit per axle, and you were weighed as you crossed the scales. A flip of the switch would transfer weight to the tag. The latter is the opposite, with letting air out of the tag puts more weight on the drive which could be useful if more traction is needed.

It takes two valves on each side to accomplish this, and although the valves are identical, they are plumbed differently. On one, the air supply from the COACH is plumbed into the NC port, so when the valve is activated, the increased air pressure is added to the tag, and the pressure from the Height control valve is blocked. In the other valve, the NC port is open to the atmosphere, so when that valve is activated the air from the HCV is blocked and the pressure in the tag bag is released.

Sorry to drag you through that, but you or a mechanic should understand that before tearing into the system.

Second thing, I appreciate the closeup of the valve. Mine do not look like that, BUT that does not mean anything. If you wish to replace that valve you need a 3 way 12V solenoid valve with the appropriate sized NPT fittings.

And yes you can bypass the valve by connecting the in and out air lines. If it is the valve connected to the coach air supply you will need to block off the coach air supply.

Please support the coach, when you release the pressure on that valve, that side of the coach will drop all the way to the suspension stops it.
Thank you, Richard. The extra details on that explain the 3 position switch as well.

Quote:Please support the coach, when you release the pressure on that valve, that side of the coach will drop all the way to the suspension stops it.

Yeah, there's definitely a reason I didn't pull it out to look for a part number.   Wink  And I think I'll lower the coach onto my cribbing before I even get under there to remove it.
This ended by being a split fitting rather than the valve itself.
Nice find! Tough to see sometimes. Looks like it was overtightened at one point.
Did you happen to see a part number on your valves?