Air Leak--Check valve

Topic: Air Leak--Check valve (Read 1576 times) previous topic - next topic

Re: Air Leak--Check valve

Reply #25 – July 05, 2023, 01:34:57 pm

Me neither on my 2015 IH--mine is the same as Turbojack's --no desiccant. The FOT air system schematics list the assembly as a "water trap" with a "filter" inside. There is a blow-off solenoid at the bottom of the glass bulb that exhausts each time the pump runs and then shuts off. PS--I was able to open the chk valve and rehabilitate it--it's in two halves and has an O-ring to seal it. Inside is simple--a mental disk covered with a rubber material closes against a molded plate on one side, and a very weak spring on the other side. Again, my valve was full of rust with no movement of the disk.

Re: Air Leak--Check valve

Reply #26 – July 05, 2023, 01:51:39 pm

Quote from: OldScout – July 05, 2023, 01:34:57 pm

Me neither on my 2015 IH--mine is the same as Turbojack's --no desiccant. The FOT air system schematics list the assembly as a "water trap" with a "filter" inside.

You can see the "filter" in this write-up (and you can see how the bowl cracks due to thermal cycling and the "filter" corrodes over time). I'm reasonably certain the water separator bowl on our former 2003 is the same as your and turbojack's IHs have. We've seen a 2008 Nimbus with a catastrophic failure of that bowl.

HWH Filters and Bowls

Re: Air Leak--Check valve

Reply #27 – July 05, 2023, 03:27:55 pm

The list of what I "don't know what I don't know" continues to go. The good news is that I have conquered most of my air leaks and for the time being, I am living in the "land of good enough!" Finding and fixing the check-valve was a major improvement for maintaining air pressure. What I don't know is where the air was going to that leaked back thru the chk valve. The "water trap," the 12v pump pressure switch, and another air line all tee into the manifold on the pump. There doesn't appear to be another check valve in sight. So, a leak-down in any of the aforementioned attachments to the manifold would, you think, cause the pump to start, eg, like when using the pneumatic doors, unless the HWH system ultimately controls power to the pressure switch and pump relay?

Re: Air Leak--Check valve

Reply #28 – July 08, 2023, 12:14:45 am

I had a air leak on the main slide bladder last year just before our trip to Alaska, Could not get in for repair at FOT, MOT or NMS so off to HWH on our way to Alaska.

HWH replaced the main slide bladder and serviced the Aux air system, one of the things the service manager mentioned was they stopped using the desiccant dryers and just added a second moister trap due to all the issue's caused by the desiccant dryers carrying trash into the valves and solenoids. One of the other things they found while servicing the Aux air system is the brass cross that is on the discharge of the aux. compressor has a built in check valve and was leaking the system off slowly causing the compressor to run. I was glad I had them leak check the system while having the bladder replaced. I would have never found that check valve built into the brass cross it was totally hidden.

Re: Air Leak--Check valve

Reply #29 – July 08, 2023, 09:13:02 am

Quote from: zmpm01 – July 08, 2023, 12:14:45 am

One of the other things they found while servicing the Aux air system is the brass cross that is on the discharge of the aux. compressor has a built in check valve and was leaking the system off slowly causing the compressor to run. I was glad I had them leak check the system while having the bladder replaced. I would have never found that check valve built into the brass cross it was totally hidden.

So you are saying in this area circled in blue there is a check valve in there?

Re: Air Leak--Check valve

Reply #30 – July 08, 2023, 10:06:23 am

Geodmann, ref my post above, was able to separate the two halves--they are sealed with an o-ring but suspect yours is rusted shut. Simple insides--a small disk with a rubber covering on one side, weak return spring on the other. Rubber side of disk closes against a plate with a slightly raised ring for a sealing surface. Was able to clean up the rust and return the valve to function but will eventually replace it--perhaps with the Haldex brass version--might help with the moisture/corrosion issue from the aux air pump.
PS--Seem to have my air leaks under control, right now, but there are several of these check-valves thru out the air system. Again, if maintained, the engine drier probably does a good job of controlling moisture--but have to wonder what condition the other valves are in. My experience--the external leaks are easier to find and fix; the internal ones, not so much.

Re: Air Leak--Check valve

Reply #31 – July 08, 2023, 10:21:41 am

Quote from: zmpm01 – July 08, 2023, 12:14:45 am

One of the other things they found while servicing the Aux air system is the brass cross that is on the discharge of the aux. compressor has a built in check valve and was leaking the system off slowly causing the compressor to run. I was glad I had them leak check the system while having the bladder replaced. I would have never found that check valve built into the brass cross it was totally hidden.

The above bolded comment jogged my memory. There was a service bulletin back in 2003 for this, but it was on "complaint basis", no owner notification:

Re: Air Leak--Check valve

Reply #32 – July 08, 2023, 11:36:57 am

Quote from: Michelle – July 08, 2023, 10:21:41 am

The above bolded comment jogged my memory. There was a service bulletin back in 2003 for this, but it was on "complaint basis", no owner notification:

Thanks, Michelle, you are great.

Who would have thought that what looked like a regular 1" +/- nipple had a check valve in it. I don't' think I have ever seen anything like that.

When I was looking at the air compressor setup I was always wondering where the check valve was that was keeping the blow-off solenoid from releasing all of the air from the tanks when it released the air/water from the bowl. I don't think mine is leaking there at the moment but it is possible it could be a small leak.

Re: Air Leak--Check valve

Reply #33 – July 08, 2023, 12:26:35 pm

Just a reminder from a previous post while on the air subject, Milton air products still has a sale going, many regulators and fittings 80% off.

Quality stuff.

Re: Air Leak--Check valve

Reply #34 – July 08, 2023, 06:21:50 pm

The plot thickens, at least for me. I had no idea about the additional check valve in air pump tee. Nor do I really understand what triggers the generic air pressure switch [gray box] attached to the tee. Know that my leak downs reduced significantly when I rehabbed the aforementioned in-line check valve in this post. Assume there is a check valve for the Aux tank too? Right now, my Aux pump doesnt run very much, rarely. My final test is to be in a place long enough with the auto level on, so the DOT tanks eventually deflate below 60PSI and isolate. I know aux. pump may run if I inflate/deflate bladders to move a slide, or eventually, if we use the pneumatic doors. I "assume" that below 60PSI in the DOT tanks, the aux. pump will supply air if the auto-level needs to inflate a bag?

Re: Air Leak--Check valve

Reply #35 – July 08, 2023, 06:34:16 pm

Quote from: OldScout – July 08, 2023, 06:21:50 pm

I "assume" that below 60PSI in the DOT tanks, the aux. pump will supply air if the auto-level needs to inflate a bag?

The short answer Yes.

Mike

Re: Air Leak--Check valve

Reply #36 – July 09, 2023, 04:58:57 pm

Getting ready to install kit in my six packs and replace the check valves as well, since I am under there! I found this online from Van Horn Truck, Haldex KN23000 check valve for $10.99 ea. This is a brass check valve and at a really good price. Hope this helps some out there! 1/2 male, 1/2 female.

Re: Air Leak--Check valve

Reply #37 – July 09, 2023, 10:41:12 pm

I replaced the bad check valve that is in the line from the compressor to the AA air tank. After I replaced the check valve I ran the HWH compressor, it took little over 6 minutes to cut off. After it shut off I turned the power off to the compressor. Today I go out and check the pressure valve on the bath door and it read zero. I then went and ran the compressor again and this time it only took 3 minutes to shut off. I figured that was because the AA tank did not have any or a small leak and the compressor did not have to fill that tank from empty. I then started hunting down the leak and I found it in a fitting feeding the bed air door.

While I was looking for the part number of the fitting I was needing I looked at the air semantics. I did find the on the drawing that Michelle informed us about above.

I have come to three conclusions.
1. Coaches with Active Air have two air tanks. One is for the air bags and the other is for the slide bladders, step cover, and both pocket doors in the bedroom. The pressure switch on the HWH air compressor only is reading the pressure in the bladder tank. If the AA tank runs down and the check valve works, the pressure switch will not see it. That is why when you try to level the coach with the engine off, the compressor will run since the pressure switch has no idea how much air is in the AA tank.
2. I have read multi time about comments about the blow off solenoid is leaking, or the bowl for the filter is bad/leaking. I think the only way you should be able to figure those out is while the compressor is running. With the check valve between the filter and the pressure switch once the compressor shuts off there should be no pressure in the filter bowl, that is unless the check valve between the filter and pressure switch is bad and leaking.
3. Michelle needs to apply for a job as tech support for Foretravel.

Re: Air Leak--Check valve

Reply #38 – July 11, 2023, 01:52:59 am

Thanks Michelle for answering there question's and posting the updated configuration performed in 2003, My coach still has the original configuration as in the before picture and I will perform the update. I like the double check valve set up. This is the first time I've had a chance to check on my last post.

Re: Air Leak--Check valve

Reply #39 – August 31, 2023, 03:26:48 pm

This is a great info thread.

When I took ownership of my IH45 back in April it had a number of air leaks and the compressor would run every 10-15 minutes for a bout 90 seconds. After chasing many I had the coach in MOT for other service in June. While there I had them chase some of the air leaks down too. They found a few more plus the pressure switch had issues.

After I left in June my compressor probably ran once or twice every couple of hours at most. Now into August and camped/stationary for the last month, I notice it running more frequently again, like every 30-40 min or so. Chasing leaks I didnt find any in the main bay when the compressor had shut off but I did notice the solenoid under the plastic bowl felt loose. I could actually move it up and down which didnt see right. In addition I noticed every day the bowl seemed to be collecting a lot more moisture then previous times.

I took it all apart, tried to reseat/reseal the fittings at bottom where the solenoid connect and reassembled. For about a day it seemed to help a lot with much less running. Then I notice an odd behavior...over night in the very early hours of the morning the compressor would run every 10 min for 40 seconds. I pulled the fuse and left for half a day. Rechecked all the fitting work on around the solenoid (never was able to really see an air leak with soap water/kids bubbles). When reinstalled the fuse strangely the compressor went back to a once an hour 40 second run for rest of the day.

Again over night it went to the 10 min cycling behavior. Pulled fuse/left it off half a day/re-installed and back to the once an hour running.

Reading this whole thread multiple times and looking at my suspect parts, I went ahead an ordered new bowl, solenoid assembly, and the check valve for good measure.

Anyone ever see that behavior with cycling and then it would go away after a period of being off/disconnected? I was wondering if possibly the solenoid may have had something to do with it under the bowl and all the extra moisture I am seeing the trap/bowl.

Thanks

Re: Air Leak--Check valve

Reply #40 – August 31, 2023, 04:51:47 pm

Quote from: tsonby – August 31, 2023, 03:26:48 pm

I noticed every day the bowl seemed to be collecting a lot more moisture then previous times.

I took it all apart, tried to reseat/reseal the fittings at bottom where the solenoid connect and reassembled. For about a day it seemed to help a lot with much less running. Then I notice an odd behavior...over night in the very early hours of the morning the compressor would run every 10 min for 40 seconds. I pulled the fuse and left for half a day. Rechecked all the fitting work on around the solenoid (never was able to really see an air leak with soap water/kids bubbles). When reinstalled the fuse strangely the compressor went back to a once an hour 40 second run for rest of the day.

Again over night it went to the 10 min cycling behavior. Pulled fuse/left it off half a day/re-installed and back to the once an hour running.

A couple of questions -

how much is the temperature dropping from daytime to overnight?

How humid is it where you are?

Does the IH have a desiccant bowl as well or just the condensate bowl?

When the compressor kicks on at the 10 minute cycling behavior, do you see any out-of-level indicator lights on the control pad?

Have you checked the air tank drains for signs of moisture?

At a 10 minute interval, that doesn't sound like the coach waking up to relevel (that's usually every 30 minutes), but rather something dropping below a lower air pressure limit, possibly due to cooling temperature contraction of the air or moisture somewhere in the system.

Re: Air Leak--Check valve

Reply #41 – August 31, 2023, 05:29:59 pm

Quote from: Michelle – August 31, 2023, 04:51:47 pm

A couple of questions -

how much is the temperature dropping from daytime to overnight?

How humid is it where you are?

Does the IH have a desiccant bowl as well or just the condensate bowl?

When the compressor kicks on at the 10 minute cycling behavior, do you see any out-of-level indicator lights on the control pad?

Have you checked the air tank drains for signs of moisture?

At a 10 minute interval, that doesn't sound like the coach waking up to relevel (that's usually every 30 minutes), but rather something dropping below a lower air pressure limit, possibly due to cooling temperature contraction of the air or moisture somewhere in the system.

temp on south texas has been mostly 100-108 during the days...although we have been just 97-99 last two and dropping to mid 70s at night. Humidity is lower today than it has been ...around 30% and it is going above 50% at night so perhaps that would account for more of the moisture.

Just a condensation bowl unless I am missing something.

Havent checked the other drains yet. Will do that next.

I havent checked the leveling/control panel but will. Honestly we dont notice the coach level changing at all. I did run the coach after sitting here +2 weeks just to air tanks and see if any diff with 12v compressor. The air levels after 2 weeks in the tanks (A/B) on Silverleaf were single digits. So I know there is a slow leak somewhere in level/bladders likely.

The loose connection for the solenoid at the bottom of the bowl still bothers me. I can physically wiggle it and move it up and down which doesnt seem right.

Re: Air Leak--Check valve

Reply #42 – August 31, 2023, 05:40:29 pm

That solenoid is NO (normally open). I agree it shouldn't move - the fitting into the bowl should have an o-ring and a C-clip - but if that were a significant issue, the aux compressor wouldn't be able to build pressure and would just keep running. The solenoid on the bowl only closes when the aux compressor is running. Once it achieves desired system pressure or level, the compressor shuts off and the solenoid opens to relieve the compressor and blow out the condensate. That's the psssshhhhhewww air release you hear when the compressor shuts off.

(I don't think there's a timer on the aux compressor - there isn't in the older coaches. That said, I'm not sure if there's a thermal protection device on the aux compressor - if there is, maybe things are getting hot and tripping something?)

Re: Air Leak--Check valve

Reply #43 – September 01, 2023, 08:48:04 pm

Quote from: Michelle – August 31, 2023, 05:40:29 pm

That solenoid is NO (normally open). I agree it shouldn't move - the fitting into the bowl should have an o-ring and a C-clip - but if that were a significant issue, the aux compressor wouldn't be able to build pressure and would just keep running. The solenoid on the bowl only closes when the aux compressor is running. Once it achieves desired system pressure or level, the compressor shuts off and the solenoid opens to relieve the compressor and blow out the condensate. That's the psssshhhhhewww air release you hear when the compressor shuts off.

(I don't think there's a timer on the aux compressor - there isn't in the older coaches. That said, I'm not sure if there's a thermal protection device on the aux compressor - if there is, maybe things are getting hot and tripping something?)

Good info. I dont believe there is a "timer" per-say but when I was at MOT last and working through air leaks tech did say the pressure switch had a problem and needed to be adjusted as I recall. It almost always only runs 40 sec now. Perhaps a bit longer when I have had it unplugged for a day or so but then right back to 40 sec on/off/release.

I dont think its overheating or tripping. At this point seems like a minor leak or so that drives the 60-90 min run, and then humidity levels going +75% overnight from under 40% during the day that maybe causing the added runs/restarts every 10-15 min. Sometimes as I recall when it gets in that mode the runs are shorter than 40 seconds too but still over 20 sec

Parts should be here next day or so for bowl/solenoid and check valve. Going to replace those and see where I stand next.

Thanks again for response. Very helpful

Re: Air Leak--Check valve

Reply #44 – September 01, 2023, 09:20:29 pm

Keep posting the symptoms/observations - the collective will get to the bottom of this. It could be as simple as a new pressure switch.

Affiliate Notice