Air System Slow Leak

[burghere66]

The air system on my coach leaks down over several days when the coach is not in use.  I believe a slow loss of air is normal over several days.  However, the green needle on my dash gauge always leaks down much faster than the red  one. The result is the passenger side of the coach drops down in about 1 day while the driver side leaks down over 4 or 5 days or more.  Does this indicate an airbag leak or ? 

Gary B.

2002 Monaco Windsor PBDD

[Ivan K]

Assuming you have air leveling? Tank leakdown will not effect single corner or side. Try to visualize which corner is causing the whole side look like it is dropping and your problem should be between and including the sixpack and either of the two corner bags including their lines and fittings. Even 4-5 days is too fast of a leakdown if in manual/off mode.

[jacwjames]

The air leveling valve should hold air in the bags when you are moving.  So if the passenger side leaks down faster there's a problem with the air bag and/or air tubing fitting from the leveling valve to the airbag or a leak in the air bag. 

I'd get a spray bottle of soapy water and see if you can identify the leak. 

 

When I had a problem with my PPV's leaking my air bags stayed  up but the tanks would all drain pretty quick since all 4 PPV's were leaking.  So I spent a couple weeks replacing everything (PPV's, check valves, and PTC fittings).  Funny thing with the PPV's is that they were all installed  upside down, when I took them apart there was significant corrosion inside, probably from condensation that was trapped.  I did  a thorough inspection of my air bags and sprayed them all down with soapy water and found no problems.  Since my air bags are +20 years old I decided to buy and carry a couple spares.  Others are more proactive and change them out, it's a crap shoot on what the best option is. 

Since going through my air system my air tanks stay up +80 psi for a over a month.  Air bags don't leak down a noticeable amount. 

 

1 Air Bag Chassis.pdf

Edited September 10, 2023 by jacwjames

[timaz996]

7 minutes ago, jacwjames said:

The air leveling valve should hold air in the bags when you are moving.  So if the passenger side leaks down faster there's a problem with the air bag and/or air tubing fitting from the leveling valve to the airbag or a leak in the air bag. 

I'd get a spray bottle of soapy water and see if you can identify the leak. 

 

When I had a problem with my PPV's leaking my air bags stayed  up but the tanks would all drain pretty quick since all 4 PPV's were leaking.  So I spent a couple weeks replacing everything (PPV's, check valves, and PTC fittings).  Funny thing with the PPV's is that they were all installed  upside down, when I took them apart there was significant corrosion inside, probably from condensation that was trapped.  I did  a thorough inspection of my air bags and sprayed them all down with soapy water and found no problems.  Since my air bags are +20 years old I decided to buy and carry a couple spares.  Others are more proactive and change them out, it's a crap shoot on what the best option is. 

Since going through my air system my air tanks stay up +80 psi for a over a month.  Air bags don't leak down a noticeable amount. 

 

1 Air Bag Chassis.pdf 69.74 kB · 0 downloads

Looks like your system got water in it at one time or another Jim. I'm lucky my whole system has stayed bone dry.

[jacwjames]

I've always kept my air dryer serviced with a new filter every 3 years. 

The PPV's have a weep hole in the top and are suppose to be oriented with the weep hole down.  All mine were installed wrong, which is what caused the problem. 

From 2016-2021 the rig was not used much, life got in the way.  So in 2021 after a couple trips is when the PPV's started to leak.  We live in E TN so it can get pretty humid, so maybe with limited use the condensation built up in the PPV's .  They all started leaking within a couple weeks of each other. 

[burghere66]

My coach does not have air leveling.  I have hydraulic jacks to level the coach.

Gary B.

2002 Windsor PBDD

[GNRACN]

Lucky you!!

[jacwjames]

50 minutes ago, burghere66 said:

My coach does not have air leveling.  I have hydraulic jacks to level the coach.

Gary B.

2002 Windsor PBDD

Same as mine. 

So with hydraulic leveling it eliminates all the controls required for air leveling.  

Pretty much has to be either an air bag leaking, dump valve, or something going on with ride height. 

You say it's your passenger side drops so I'd be looking at the rear passenger side ride height, air lines, or air bag.

[burghere66]

Thanks,  I'll check it out when I go out to the storage facility.  BTW, it only drops after its been sitting for a day or so.  When I'm driving its at the proper height.  Do you recall where you purchased your air bag, the part number and the price?  I probably should buy 2 to keep on hand.  Mine are 2002 original.  Are they difficult to change out?

Gary B.

2002 Monaco Windsor

[jacwjames]

38 minutes ago, burghere66 said:

Thanks,  I'll check it out when I go out to the storage facility.  BTW, it only drops after its been sitting for a day or so.  When I'm driving its at the proper height.  Do you recall where you purchased your air bag, the part number and the price?  I probably should buy 2 to keep on hand.  Mine are 2002 original.  Are they difficult to change out?

Gary B.

2002 Monaco Windsor

Original air bags were Firestone.  In 2021 when I was trying to buy there weren't a lot of choices.  I ended up buying Conitec $311 including shipping for 2.  I bought them from TruckandTrailer.parts   https://www.truckandtrailer.parts/conti-9376-monoco-air-spring

Looks like the price actually came down a little.

I watched several videos and read a bunch of posts on how to change an airbag.  I'm confident I can do it just don't know how hard it would be. 

 

 

[burghere66]

Thanks for the info on the airbags.  I hope to get a look at them this weekend.