[encantotom]

i have been trying to figure out where my small leak is that causes my front drivers side airbag to slowly go down.  

so, i have been playing and tracing things for about a week.  

i raised the coach all the way up using the leveling system and then used my new 22ton jackstands to keep the front up.  i lowered the coach all the way down...i am too big to get to the front 6 pack without it being raised up.  

i identified and verified the location of each solenoid valve.  the same for the air lines coming in and out of the six pack.  what really baffled me for a few days is that someone had written on the yellow air lines what they were in magic marker.....and they were WRONG.  

i used the test rig to check pressures.  i did it a little different than richard outlines.  i found the lines that went to the ping tank that feeds the airbags.  i connected one side of the test gauge to the drivers side front airbag and the other side of the gauge to my shop air.  then i used the valve on the gauge to air the bag up to 100 psi and made a note of time.  it leaked down 18 psi in 11 hours.  not sure that is alot or not for sure.  

i sprayed alot of kids bubbles on the airbag and as much of anything else i could see.  no bubbles.  

while i was under there, i used a magic marker to label the six pack and used a label maker to label each wire.  i marked the airlines (correctly) with magic marker as well.  

i also took all six valves out and rebuilt them using my rebuild kit.  

i aired everything back up, sprayed some more bubbles on everything and didnt see anything.  

i measured the coach height at the front and back wheelwells and made a log and will check in the morning.  

tom

[Richard]

Tom,

I think the 18 lbs in half a day is significant. Here is why. On my coach it takes about 90 psi to float the front end. By float, I mean to supply enough pressure to the bags to get the coach to start raising from dead flat on the tires.

So really the pressure we are playing with is 120 lbs max air pressure on the supply side, and 90 lbs on the low side to float the coach. I really think that in 24 hours at that leak rate the front corner would drop inches. Making some crude leak rate calcs have you going from 120 psi to 80 in two days or so. That would be enough leak to allow the that bag to settle from full extension to no extension.

I got a good laugh at the mislabeled air lines. I have discovered this week that six pack orientation is NOT the same on all six packs Newell made. On some the up solenoid is in the middle, and on some the up is on the end. How do you tell? Look at the air supply line to the six pack. If it comes in on the end horizontally, away from the travel solenoids, the up will be on the end where the air supply line comes in. If the air supply line comes into roughly the center of the six pack vertically, then the up will be in the middle. And if you happen to have a six pack manifold made by HWH, it is plumbed way different than the ones Newell made. The point is, that it is not safe to make assumptions about the sixpack valves, it is best to confirm their identification using a tried and true steel washer sticks to a energized coil method.

[77newell]

Tom: from your description it's not clear to me at what point you connected the temporary air supply. In any case, it looks like you will have to test by segmenting the system into smaller an smaller pieces until you find the culprit. My guess is an airbag, but that is just a guess based upon the fact that they are the only moving part in the segment you tested.

I agree with Richard on the rate of loss. I can park my coach for weeks in warm weather and not have it drop at al. In winter it will drop in a week or so, the solution is to ignore it and move the coach somewhere warm with me in it

[encantotom]

tonite after 9 hours it had dropped a little less than half an inch.

tom

[encantotom]

i have 3/8" lines for all the air in and out of the six pack. both front and rear

red is coming in and yellow out. on the red air in line there is a T that has another yellow line on it that goes into no mans land.

the back one is the same. any idea where that T'd line goes? looks like it is a supply line for something else. also, it looks like there is a check valve on it.

tom

[encantotom]

could that yellow supply line be the one that goes to the HCV?

tom

[Richard]

When you said it dropped half an inch. I assume you removed the jackstands. Did you leave the pressure gauge on it? If so, how much pressure did it lose?

[77newell]

On my 93 coach, the supply to the HCV is tapped off the supply to the six pack. Physically mine looks a bit different because the aluminum block holding the solenoid valves is machined different from Tom's but functionally is the same

[encantotom]

so i will make the assumption that line is for the hcv's. richard, i did not leave the gauges on.

it had dropped another 1/2 inch overnight. the rear is dropping a little, but only 1/2" over 20 hours or so and i think that is just because the front is dropping.

i tried to get up around the tanks, but just jacked up there is not enough room for a big boy to get up there.

i assume it just goes directly from the six pack to the ping tank and then directly from the ping tank to the airbag. is that correct?

to

[Richard]

I can't say if that is the supply line for the HCV. I just don't know.

Yes, the line goes from the six pack to the appropriate air tank via 1/4 or 3/8 tubing, then the air bag is connected to the tank via the 1 " hose. The purpose of the tank and the large hose is to use the tank as part of the air spring resulting in a lower spring rate aka softer ride.

Any idea how that settling rate compares to before?

Jon makes a good point for any followers of the thread. I have seen three different six pack manifolds on Newells, not to mentioned the non manifold setup on the classics. The first manifold has the solenoids equally spaced and the supply line comes into the top of the manifold about midway. On that manifold the up solenoid is in the middle. The second manifold, also with equally spaced solenoids has the supply line entering from the side. On that manifold, the solenoids on the end next the supply are the up solenoids. And the third manifold is like the one in Tom's pictures. The supply line comes into the back.

When I learned this last week, it made years of befuddlement about the solenoid arrangement make sense. I had seen diagrams of solenoid identification that disagreed with mine. I also had people tell me that a diagram I drew was wrong. I laughed when I discovered they comes in different flavors.

The point is that it may take a little detective work with energizing the different solenoids and using a steel washer to confirm which solenoids are travel, up, and down before a guru starts diagnosis on a leveling issue.