Air Dump

[FOURWHL]

Hmmm good info. Didnt realize the HCV was air only all the time.

Ryan1 good thinking, but there's a couple of things I dont like.
1. If that valve fails (or some part giving it power) then you're driving down the road again with no air in the bags
2. My levelers need the motor on to run, or so thats what the instructions say.

Now you could flip that to be a normally open valve, and then just power it closed with the same switch you use to dump between the bags I'd think. Would lose the ability for minute height adjustments, but I think in the case where this would be valuable is where the rear end is way in the air and you need as much drop as you can get.

[Ryan1]

If you're running two normally closed valves then all that would happen if you lost total power or had a failure would be that you wouldn't be able to add air. If the failure happens while aired down then it could be an issue but if it happened while driving you probably wouldn't even notice since the existing pressure would just be trapped in the closed loop between the valve and the bags. Valves are cheap so you could keep a spare on hand and it'd be a quick fix if a problem ever arose.

[MasterBlaster]

I have been going back and forth on what to do with all this information and just thought that I would share with everyone what I found and done. The electric valves are a good idea, but as mentioned the electric has to stay on for the bags to stay dumped. Did not like this so I elected option 2 which is manual. Once I got under the rear it became clear that the issue is not how to put a dump valve on our rigs, but more importantly how to activate the dump valve we already have. It took me about an hour to drive to Lowes and a heavy truck repair shop to get the items needed to do this manually. Since the dump valve is air operated I needed to do was activate it, found it to be very simple. Here is what I done with some pictures:

1. Purchase these items:

- 1/4" threaded ball valve (Lowes)
- 3/8" push to connect elbow with 1/4" threads (Truck Parts Store)
- 1/4" push to connect straight with 1/4" threads (Truck Parts Store)
- 3/8" push to connect "T" (Truck Parts Store)
- 1/4" push to connect "T" (Truck Parts Store)
- 6' 3/8" airline (Truck Parts Store)
- 6' 1/4" airline (Truck Parts Store)
- 1/4" ball valve plastic (Lowes)

2. Connect 3/8" push to connect elbow to one end of the ball valve, connect 1/4" push to connect elbow to the opposite end.

3. Open Bay door directly behind drivers side rear tires (should be service bay on most of our rigs) decide mounting location for this valve.

4. Drill 1 3/8" hole and 1 1/4" hole on back side of bay where you want to send the air lines through. (might need to go under vehicle first to make sure your not drilling into anything important)

5. Attach the 6' 3/8" airline to the 3/8" push to connect then attach the 6' 1/4" airline to the 1/4" push to connect

6. Now thread each air line thru the appropriate drilled hole until your valve is roughly located at the mounting location.

7. Now mount the ball valve with airlines connected inside your bay.

8. Now take and cut the 1/4" airline approx. 6" from the ball valve and insert the 1/4" "t" push to connect. Take and cut off about 4" of the 1/4" airline going thru the bay wall, and attach to the bottom outlet of the "T" connector, then take and connect the 1/4" airline running thru the bay wall into the remaining end of the "T" connector.

9. Now go underneath your rig and we can finish up. Don't forget to take with you your cutters to cut airline

10. Take and route your airlines that you inserted thru bay wall and route them over frame and up to the HCV (hight control valve) on the driver side

11. Find the "T" connection on the front side of the HCV (it should be attached to the HCV and have the main air supply line attached coming from air tank and then going over to passenger side HCV. Cut this line approx. 8-10 inches past the "T" connector (between the "T" connector and passenger side HCV). BE AWARE THAT THIS LINE PROBABLY HAS AIR IN IT AND WILL SOUND LIKE YOU JUST SCREWED UP, YOU DIDN'T JUST BE SAFE. Attached your 3/8" "T" connector and then reattach the main air supply line. Connect the 3/8" airline you installed into the bottom side of the "T" connector.

12. Find the opposite end of the HCV (end towards front of vehicle) and you will see a 1/4" "T" connector with a 1/4" airline running back over to the passenger HCV. On the bottom side of this "T" connector is a plug, remove the plug and insert the 1/4" airline you installed into the bottom of the "T".

13. DONE (secure your airlines, make sure they won't rub and wear on any sharp edges)


Now your ready to test it.

Start Truck and build up air pressure, once air is full activate large ball valve and your bags are going to dump immediately.

To fill bags back up release pressure on 1/4" line by turning the small ball valve you installed on the 1/4" line. Once pressure is released close valve and the turn the large ball valve and bags will inflate back up.

[MasterBlaster]

Here are pictures to go with previous post

[Webefine]

Very nice! I did the same thing but added a third valve so I can air my bags up beyond normal ride height for when I need a little extra ground clearance.

[MasterBlaster]

Originally Posted by Webefine

Very nice! I did the same thing but added a third valve so I can air my bags up beyond normal ride height for when I need a little extra ground clearance.

Thats why I love this sight so much, everyone is willing to share.

[dlfishing]

Master Blaster
Do you have both air bags going through the same dumping valves?

[Webefine]

No, I did valves on both sides so I can raise or lower each side separately.

[dlfishing]

Originally Posted by Webefine

No, I did valves on both sides so I can raise or lower each side separately.

I have copies of the photos on yours. I want to do the minimum, just to dump while I set the jacks. Don’t need to raise them, rollers on the back seems to have solved that problem.
Could I connect both to the same valves in the wet compartment? The other side has too much in it to be convenient.

[Webefine]

Yes you can do that.

[MasterBlaster]

Originally Posted by dlfishing

Master Blaster
Do you have both air bags going through the same dumping valves?

yes they both dump at the same time with just one valve. Did not have the need to be raising and lower one side or the other.

[dlfishing]

Another thought to both.
My reason for wanting dump valve is to lower the height of the motorhome after jacks are lowered as previously mentioned.
I got to thinking, dangerous I know, if you lower the rear the front is still at the original height so front jacks are starting high thus rear jacks will have to extend the same to get level. What’s the point in dumping to begin with.
What has been your experience in dumping the air shocks?

[rskeans]

Originally Posted by dlfishing

What’s the point in dumping to begin with.

In thinking about this, the front w/o jacks is a constant. If the rig is on a slight down slope you wouldn't want the front jacks to raise unnecessarily. Starting out with the bags dumped would mean that the front jacks are not extending necessarily. So it would depend on your parking spot if you dump or not. IMHO.