iRV2 Forums

iRV2 Forums (https://www.irv2.com/forums/)
-   Class A Motorhome Discussions (https://www.irv2.com/forums/f258/)
-   -   Losing Air (https://www.irv2.com/forums/f258/losing-air-547019.html)

Blularry 07-26-2021 07:54 AM

Losing Air
 
I have an 08 Winnebago Vectra 40TD. I have no problem with the air psi filling quickly when I start the coach. However, once I turn off the engine the rear starts to lose pressure right away, almost like I am dumping the system. I have only had the coach for a few months so I'm still learning about Class A's. What should I be looking for underneath? Is this something I can spot myself or should I just take it to a shop? It does maintain the psi while I'm driving. Thanks for the help.

Argosy 07-26-2021 09:37 AM

It stays up while it's running because the compressor output is greater than the leak.

You should be listening for the source of the leak, but you shouldn't be under it without it being blocked so you don't get crushed. Air it up, slide some jack stand under it where it's safely supported as is sits. Shut the engine off, walk around it and get an idea where the leak is. When you've narrowed it down you can slide under and locate it.

Be very careful where you put your hands and arms, air bags raise the bodies 6-10" and what looks like a lot of clearance can change quickly.

Gary RVRoamer 07-26-2021 03:31 PM

The compressor can keep up with a huge leak. You have a major rear leak, or maybe a failed ride height valve. Any truck shop or RV chassis shop should be able to find and fix quickly. I would not go to an RV dealer for that sort of thing unless they are big enough to have a dedicated chassis shop.

FIRE UP 07-26-2021 11:09 PM

Quote:

Originally Posted by Blularry (Post 5846818)
I have an 08 Winnebago Vectra 40TD. I have no problem with the air psi filling quickly when I start the coach. However, once I turn off the engine the rear starts to lose pressure right away, almost like I am dumping the system. I have only had the coach for a few months so I'm still learning about Class A's. What should I be looking for underneath? Is this something I can spot myself or should I just take it to a shop? It does maintain the psi while I'm driving. Thanks for the help.

Blularry,
Your coach is an '08, making it around 13 years old. And you don't say what the miles on it are. My point is, being that old, it's possible that your air leaks can come from many, many places. As has been suggested, it's potentially possible you may have a faulty ride height sensor/valve. If you're not familiar with them, they're a little air control valve that has a lever on it, that attaches to the axle and the frame, close to tires.

Typically, Freightliner installs three of them. In our coach, an '04 Itasca Horizon 36GD with the CAT C-7 330HP, we have one ride height sensor in the rear and two in the front. Why Freightliner did it that way is beyond me but, it is what it is. And, what they do it simple. Based on the adjustment they're set to, they control the "ride height" of the coach, by allowing a given amount of air to the air bags to raise the coach to a set height.

Conversely, they also release air, if the load on the coach is LESS than what it takes to compress the air bags so the adjustment is met. They work constantly to keep the coach at its prescribed height while the coach is operating.

Now, if you're loosing air rapidly, one of the causes could be a faulty ride height sensor. It could also be an air bag or, more than one air bag. It could be fittings in the air lines at valves. It could be pressure protection valves on the tank(s) etc. As has been stated, one must take great care while squirming around under a 15+ ton coach, searching for air leaks. I recently found a massive air leak from one of my front air bags. I replaced all four of them and a pressure protection valve and now my coach will hold air at or around 110-120 for well over 24 hours. I still have a tiny leak somewhere and, when we get done with all our short little trips this summer, I'll be back under there with my little stethoscope to find the culprit.

But, a sprayer with a good solution of soap (dish soap) and water will provide great results of a hissing air leak. Just be careful. If you wanted to keep the coach up while searching for your leak, you can plug in a home air compressor to the front quick release air chuck in the front of the coach. That should sustain your height while searching. Good luck and report back what you find.
Scott

jacwjames 07-27-2021 07:14 AM

You should be able to hear that bad of a leak but need to be careful if getting under the coach. I'd suggest blocking it up when it is at full ride height with engine running. Then shut off the rig and use soapy water or a tool to find the leak.

Blularry 07-28-2021 06:30 AM

Losing Air
 
Thanks for all the great information. I have decided this is past my skill level and have an appointment with a near by Freightliner to address the issue. Again, thanks for all the input. This is a great forum.

bneiva 07-28-2021 08:28 PM

If you would....once the problem has been identified, can you please tell us what it was? What you have to report could be of great value to others.

Bill

Blularry 08-03-2021 01:04 PM

I am happy to report that the air issue has been resolved. I took the coach in to Advantage Truck Group in Lebanon, New Hampshire. They found a leak in the rear passenger side air bag. They didn't have one in stock but found one close by and personally drove to get it. Within four hours we were back on the road with a new air bag installed. They charged only $411.00. I was ready to be hit for a much bigger bill. Highly recommend them if you are in need of any Freightliner work and and are in the area.

TampaDave 08-03-2021 06:00 PM

Question is, whats the life span of an air bag? I have an 08 too, replacing an air bag on the road was an adventure I would like to forget but cannot. Maybe 13 years is the number eh


All times are GMT -6. The time now is 10:11 AM.

Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2021, vBulletin Solutions, Inc.