Air tank dumping upon acceleration 2003 Journey

[natbanks]

We purchased a used 2003 Winnebago Journey 36ft a few years ago. Everything worked fine for the first 12 to 15 trips then we purchased a small toad. Now when towing whenever I accelerate we hear an air rushing sound near the front of the cabin... then when I back off the accelerator the sound immediately ceases as if a valve has been closed. Then on next heavy acceleration it repeats again. We have only taken one trip prior to winter when it occurred but I suspect it will resume... any thoughts?
Thanks in advance.

[Ray,IN]

It could be a faulty emergency brake valve. That would make a sound under/behind the dash.



When was your air dryer unit last serviced? The desiccant filter should be replaced every 3-4 years on a recreational MH. If that filer has never been replaced, I recommend replacing or rebuilding yours now.
Your description also sounds like perhaps the air dryer is not functioning and when you accelerate the increase in air pressure/volume is venting to the outside instead of flowing through the filter. However that sound would be towards the rear of the chassis.

[ftodaro]

An air leak that big should be something you can find. i would start out with an aired up system with the motor off to see if you can hear a leak. I do not know anything that should be connected to the accelerator per se, but, I do know that the leveling valves are active and if your coach is pitching for or aft it may be a factor that that would be a faulty valve. Let us know what you have found when you take a look.

[DNC]

In response to Ray,IN's answer, I attended a session at the Winnebago GNR last year and heard the Freightliner guys say that replacing the desiccant air filter is one of the most overlooked maintenance items that, if not done, can result in very costly repairs. They said that, over time, the desiccant can dissolve and turn to powder which is then distributed throughout the air system. According to them, if that happens, you'll likely need to replace the air system. They estimated that it would cost $12K to $15K to replace the air system.

[ernieh]

Is the volume control on your rear camera off?

[csmart94]

Originally Posted by ernieh

Is the volume control on your rear camera off?

There should be no reason you hear engine noise up front on a diesel pusher, the camera volume would be the only thing that make sense to me. If there was a leak in the air system is shouldnt change with the throttle

[natbanks]

Thanks to the many folks replying. First thing I did was replace the brake valve controller, hoping that was the problem... nope, not so lucky.

This weekend we went to the lake for Valentines Day and on the way home decided to refill the propane tank BUT before we could pull into the Love's station we lost all air pressure and were dead in the water.

Fortunately we were able to get a mobile diesel mechanic to come and help.
1. Was a hose busted? No.
2. Were the pumps making air? Yes.
3. Why weren't the tanks holding air? Blowback valves were seriously corroded and permitted all air to leak out. (he removed, cleaned and honed them and upon replacing they worked as designed.)
4. Replaced the over-pressure safety valve and it began holding air.

In the process he noted that both tanks were full of water.. so obviously the desiccant canister had never been changed in the past 21 years - certainly not in the 2 years we have owned it. I plead ignorance but never again.

Temporarily bypassed the dryer until the new canister comes in, just so we could move RV from Love's parking lot to our home.

The sound we heard was the over-pressure safety valve - and due to my deafness it sounded like it was coming from under the dash.

Thanks again to all.

[tim myers]

I certainly understand deafness and sounds being hard to distinguish. Did the mobile tech share with you about periodicity pulling the lanyards to manually dump air and water if any exists? My Journey has three such lanyards. Two on one side and one on the other behind the steer tires. I forget which is which. You can see them by turning the wheels all the way to the left and right, looking from behind the tire. I use my awning tool to hook and pull them.

[Ray,IN]

Originally Posted by tim myers

I certainly understand deafness and sounds being hard to distinguish. Did the mobile tech share with you about periodicity pulling the lanyards to manually dump air and water if any exists? My Journey has three such lanyards. Two on one side and one on the other behind the steer tires. I forget which is which. You can see them by turning the wheels all the way to the left and right, looking from behind the tire. I use my awning tool to hook and pull them.

the manual tank drains are to be used as specified in the owners manual even if the tanks have automatic drains too.

[Jim_HiTek]

@natbanks

I have a '02 Winnie, 36', Journey DL diesel pusher and I've never changed my desiccant canister. And I've rarely pulled the drain cords that are under the chassis behind the passenger wheel (making them difficult but not impossible to access).

Where was your canister? In the front under the hood? Under the steps? In the rear?

Thanks.

[Ray,IN]

Originally Posted by Jim_HiTek

@natbanks

I have a '02 Winnie, 36', Journey DL diesel pusher and I've never changed my desiccant canister. And I've rarely pulled the drain cords that are under the chassis behind the passenger wheel (making them difficult but not impossible to access).

Where was your canister? In the front under the hood? Under the steps? In the rear?

Thanks.

The air dryer should be bolted to the frame just forward of the rear axle on starboard side. Given it has never been maintained, I suggest replacing the entire unit instead of only the desiccant filter.
The manual drains should be easily pulled by using the awning pull rod. If you have a spartan chassis, this is the procedure, which should also apply to any chassis with air brakes.