Skip to main content ↑ ↓
Topic: More air leaks (Read 690 times) previous topic - next topic

More air leaks

  My 2001 U295 leaks down on the left front overnight.  No obvious leaks in the airbags or hoses.  The aux level pump comes on but the coach will not level until the ignition key is turned on.  My thought is that something is leaking internally.  The dash gauges show only a few pounds pressure drop.  Any suggestions on where to look?

Re: More air leaks

Reply #1 –
Rebuild the six-pack.using kit from Tom McCloud that posts here.
Rudy Legett
2003 U320 4010 ISM 450 hp
2001 U320 4220 ISM 450 hp
1995 U320 M11 400 hp
1990 Granvilla 300 hp 3208T
Aqua Hot Service Houston and Southeast Texas

Re: More air leaks

Reply #2 –
Swap the front dump solenoid valves if the problem follows the valve you found it.
At least you can eliminate the valve.
John Duld
1995 U320C SE 40'

Re: More air leaks

Reply #3 –
Thanks guys.  I'll post the results

Re: More air leaks

Reply #4 –
UPDATE:  Rebuilt the 6 pack using Tom's kit.  Smooth procedure, sonic cleaned all the parts.  Double checked all the wiring connections with my labeling and the harness labels.  Coach still lays down on the left front overnight, and now raises on the RF.  We are looking at 1 1/2" droop LF and 1 1/2" raise RF.  Turn the ignition switch on and the coach levels.  My understanding is the solenoids are normally closed.  If this is correct, the RF raise solenoid is getting power when the system is off.  Do I understand that correctly?

Re: More air leaks

Reply #5 –
RF Raise solenoid is leaking.
2014 ih45  (4th Foretravel owned)
 1997 36' U295 Sold in 2020, owned for 19 years
  U240 36' Sold to insurance company after melting in garage fire
    33' Foretravel on Dodge Chassis  Sold very long time ago

Re: More air leaks

Reply #6 –
If the RF raise is leaking, I can deal with that.  What is causing the LF to lower?  Leaking a different way?

Re: More air leaks

Reply #7 –
A different one is leaking.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: More air leaks

Reply #8 –
Is the left side leaking down or is the right side going higher throwing more weight on it ?
I say again swap the suspected solenoid with the one on the other side and see what happens.
John Duld
1995 U320C SE 40'

Re: More air leaks

Reply #9 –
Swapped solenoids.  Still getting 1 1/2 raise RF; 1 1/2 lower LF.
I'm not at all familiar with this air suspension setup.  What comes into play when the ignition switch is turned on that causes the coach to level itself

Re: More air leaks

Reply #10 –
Just to confirm that you swapped the bottom two solenoids? If so you have eliminated the solenoid valves.
Are you sure you didn't get an air hose or any wiring crossed during the manifold change.
If you had a raise solenoid powered when it shouldn't be powered you would see the coach go up in a matter of seconds (as long as you have normal pressure in the air tanks) not over night. Over night would be a leak.
Keep looking, you will find it.
John Duld
1995 U320C SE 40'

Re: More air leaks

Reply #11 –
If swapping the solenoids didn't change anything and you are in level mode then I wonder if you have a level sensor or computer problem.
That sensor sits on springs. I would gently move it a little to be sure it's free.
What level lights on the HWH control panel are on when you level the coach?
I think it goes to travel height when you turn the key(start?) on.
Now the ride height control valves control the height.
Do you get the green travel light when you turn the key on? If so it goes to travel height, it's not leveling the coach.
Two systems here:
Travel when the green travel light is on.
Top two solenoids.
When you select level it uses the level sensor and the middle (dump) solenoids and or the bottom (raise) solenoids
Only one system at a time will work.
John Duld
1995 U320C SE 40'
 

Re: More air leaks

Reply #12 –
Quote from: Buck2 –
Swapped solenoids.  Still getting 1 1/2 raise RF; 1 1/2 lower LF.
I'm not at all familiar with this air suspension setup.  What comes into play when the ignition switch is turned on that causes the coach to level itself
when you turn the ignition on, the coach may automatically go into "travel" mode. At this point the computer/level sensor is no longer attempting to level the coach. Instead, that job is handed off to ride height control valves. You have three.  There is a mechanical linkage between the valve and [essentially] your axles. If they extend too far away from the valve it exhausts air, if it gets too close, it lets air into to the airbags. 

You only have one of these valves in the front and it is at the center of the axle. So the best it can do is try to average of two sides to roughly 8.5". Because of this, if you are on even slightly uneven ground, you can see an offset between the left and right front corners. It's normal and you would hardly be the first to chase a red herring because of it.

Each corner in the back has its own ride height control valve and are therefor more precise so those should always be almost exactly 8.25" between the bag plates. Much of your side to side adjustment upfront actually comes from the back.

Again, this is only true for when you are in travel mode. Once you go into manual or auto leveling mode, these ride height control valves are taken out of play.

It is an exercise in futility to try to troubleshoot an unlevel front end, while in travel mode, if you are not on perfectly level ground
1987 Grand Villa ORED
2001 U320 4010

Not all that wander are lost... but I often am.