Aux Air Compressor running but will not deflate the bladder when extending!

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Aux Air Compressor running but will not deflate the bladder when extending!

March 31, 2022, 08:24:00 pm

Yesterday, we had some really bad weather coming in so I brought our living room slide back in and all worked fine. Bladder re inflated and all was good. Today, I tried to bring the slide back out and found my bladder would not deflate. The compressor is running and key is on and no bladder deflating. Not sure if I have a check valve or solenoid sticking, but bladder will not deflate so can't extend the slide at this time. I understand their is a way to deflate the bladder without the compressor and then when you bring out room, it will normally inflate when you turn the slide room key off. Any help would be appreciated. 2000 U320 with Thomas air compressor mounted on the ceiling of the middle bay in the upper left corner. Seems even same years are different. I also have a small tank that runs parallel with the length of the coach up overhead by the compressor and there are two quarter inch lines coming to this tank, one from compressor and the other one I believe is going to the old air lines for the air awning , which is no more. Hope this makes sense and I need help!

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #1 – March 31, 2022, 08:34:02 pm

Joe, your bladder manifold (if it the original one) is likely on the inside of the beam under the slide towards the back of the big bay. See the diagram to see what it looks like.

Disconnect the air supply line and when the key is on and the compressor is on there should be air coming out at about 90 psi. If it is connected to the manifold then air should be exhausting and there will be low pressure in the air to the bladder and it should deflate.

I had a problem like this and HWH replaced mine with w remanufactured manifold for about $250. Probably more now. The solenoid was malfunctioning.

If you have a way to suck air out of the line to the bladder try that. If you have a compressed air supply blow air across the end of the line to the bladder, it should deflate the bladder.

Needs must.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #2 – March 31, 2022, 08:42:12 pm

Thanks Roger, I have looked for that manifold per Scott and could not find it. Will look again in the morning. I do have another air compressor and will try blowing across the line to see if that deflates the bladder. Could I suck on the line and deflate it that way?
Was even thinking one of the two solenoids was not working properly.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #3 – March 31, 2022, 08:56:17 pm

Joe, take some pics and post them up. We may be able to point out what you might be missing.

I have a Mityvac that I use for pressure and vacuum testing. It comes with a bunch of fittings and could be used to draw vacuum on your seal.

Here's the one I have. Might be able to find it at an AutoParts store. Also, I have seen the vacuum only version (which is about 1/2 the price) at Harbor Freight.

Amazon.com: Mityvac MV8500 Silverline Elite Automotive Test Kit Provides...

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Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #4 – March 31, 2022, 09:14:38 pm

Keith, my phone does not want to post photos on here or I am doing something wrong. Most likely wrong! I did send some to Roger and Scott on that I have. Will check HF on the vacuum as well.
Thanks for the post!

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #5 – April 01, 2022, 07:37:00 am

Joe, the manifolds on my 2001 were mounted on the back side of the beam that runs along the top of the front basement opening on the driver's side. To see them, one must put body into the basement and turn to look back outside.

My manifolds have been replaced with real vacuum pumps, same one used for dash vacuum dampers. When the vacuum for the bladder is established, the pump cuts off. The aux air compressor does not run at all. It just keeps the aux air tank pressure up.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #6 – April 01, 2022, 08:40:55 am

Quote from: Rudy – April 01, 2022, 07:37:00 am

Joe, the manifolds on my 2001 were mounted on the back side of the beam that runs along the top of the front basement opening on the driver's side. To see them, one must put body into the basement and turn to look back outside.

My manifolds have been replaced with real vacuum pumps, same one used for dash vacuum dampers. When the vacuum for the bladder is established, the pump cuts off. The aux air compressor does not run at all. It just keeps the aux air tank pressure up.

Rudy, do you have a link on that pump? May be the answer! I have looked back from laying in the bay, but will look again! Thanks for your help as well as Roger and Keith's! I do know the 2000 was it's own animal and the '01's were changed as well as the '02's. Wondering if anyone else on the forum has a 2000 with slide that has a fix for this. Sorry about no photos, as I have tried, but can't figure out what the deal is with my phone and this site!

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #7 – April 01, 2022, 02:19:26 pm

Joe found the manifold...

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #8 – April 01, 2022, 02:20:54 pm

Joe, I bought these gauges and put on the output side of my slide manifold so I could monitor the pressure or vacuum to know what was going on. This is the gauge I used: MEANLIN MEASURE -30~30Psi Stainless Steel 1/4" NPT 2.5" FACE DIAL Vacuum...

Looking again, it looks like our manifolds are the same (yours is mounted 180* out from mine), I just have two. The pressure inlet is on the right in my picture below, and output to the slide bladder is on the left, where the gauge is. So on yours it would be the line on the left of the picture for the output side...the one you would want to draw a vacuum on.

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Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #9 – April 01, 2022, 02:34:39 pm

Quote from: WS6_Keith – April 01, 2022, 02:20:54 pm

Joe, I bought these gauges and put on the output side of my slide manifold so I could monitor the pressure or vacuum to know what was going on. This is the gauge I used: MEANLIN MEASURE -30~30Psi Stainless Steel 1/4" NPT 2.5" FACE DIAL Vacuum...

Looking again, it looks like our manifolds are the same (yours is mounted 180* out from mine), I just have two. The pressure inlet is on the right in my picture below, and output to the slide bladder is on the left, where the gauge is. So on yours it would be the line on the left of the picture for the output side...the one you would want to draw a vacuum on.

Great example of combination gauges. So much easier to see what's happening rather than guessing something you can't see.
Scott

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Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #10 – April 01, 2022, 07:57:53 pm

Well, I realized this morning that I was looking in the wrong bay. I thought that manifold was in the bay with the compressor. No, it is in the front drivers side bay at the top inside rail. Will try and work on this in the morning, as I just got back to coach. I have ordered the vacuum pump that Rudy was so kind to send me the link of and will see what damage I can do with this. lol
Will find out if the solinoid is working and go from there. May have a problem with the manifold like Roger suggested.
Thank you all for your help on this and will post results as soon as I can. Roger, Keith, Rudy and Scott, thank you for stepping up and giving me your knowledge and expertise!

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #11 – April 02, 2022, 12:33:50 pm

Well, placed an order with Amazon and my DOT fittings, a normally open and a normally closed valve are coming here on Monday, hopefully! The vacuum pump will be here tomorrow and will just hook it up to deflate the bladder and then open the slide and re inflate. Once everything is here will try my best in some documentation. Many thanks to Rudy and Roger for my picking their brains! Wish me luck, prayers, etc.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #12 – April 05, 2022, 11:31:54 am

Update: Finally got the slide bladder to deflate, thanks to Rudy and his info on a stand alone vacuum pump. I mounted this on the wall in the bay, removed the bladder line from the manifold and connected it to the vacuum pump. Then started up the coach and like normal, turned the switch on for the slide, waited for it to turn yellow and then hooked electric up to the vacuum to deflate and once done, extended the slide and re attached the bladder hose to the manifold and bladder inflated with the compressor. Now, waiting on parts and will put in two new solenoid valves, one NO and one NC, hook back up to wires from the HWH switch and install a new pressure regulator, per Roger to set at between 11-12 psi for bladder. Sorry about no photos, but wanted to at least try to explain how this will work. DW happy slide is back out. Now to get rest of parts and have this working like normal.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #13 – April 05, 2022, 12:31:44 pm

Quote from: juicesqueezer – April 05, 2022, 11:31:54 am

Update: Finally got the slide bladder to deflate, thanks to Rudy and his info on a stand alone vacuum pump. I mounted this on the wall in the bay, removed the bladder line from the manifold and connected it to the vacuum pump. Then started up the coach and like normal, turned the switch on for the slide, waited for it to turn yellow and then hooked electric up to the vacuum to deflate and once done, extended the slide and re attached the bladder hose to the manifold and bladder inflated with the compressor. Now, waiting on parts and will put in two new solenoid valves, one NO and one NC, hook back up to wires from the HWH switch and install a new pressure regulator, per Roger to set at between 11-12 psi for bladder. Sorry about no photos, but wanted to at least try to explain how this will work. DW happy slide is back out. Now to get rest of parts and have this working like normal.

Would love to get the details on your installation (and Rudy's) once you get everything hooked up and working. I bought a small vacuum pump that attaches to my portable compressor as a backup in case the aux compressor or vacuum block fails, but what you, Rudy and Roger have and/or are working on seems a better solution.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #14 – April 05, 2022, 02:09:56 pm

Will send you a message Joe. Not much going to happen here for the next few days if not through the weekend. Rain and lots of it! UGH!

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #15 – May 02, 2022, 04:31:03 pm

Alas, an update on our slide issues! I found the vacuum solenoid leaking at the base, so removed the manifold and rebuilt the solenoid but no success. Still leaking, so I installed a tee in the quarter inch line going to the bladder and installed a NC solenoid in front of the new vacuum pump I mounted and wired all into the wires going to the vacuum solenoid on the manifold. So, when I turn on the switch for the slide to deflate the bladder, it starts the new vacuum pump and opens the NC solenoid to work as normal. Then when I turn the switch off, the bladder is re inflated like normal and the new NC solenoid closes to keep air from going back into the new vacuum pump. Will try to get photos of this in the next few days, but am a happy camper now. I purchased all the quarter size tee and anything else I needed to work for the new routing of the lines at Lowes. No leaks with this push on plastic fittings! I could have just removed the manifold and by passed it, but thought if this would work, maybe later on when HWH ever calls me back, I will order a new vacuum pump for the manifold. Then again, maybe not!

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #16 – May 02, 2022, 08:42:15 pm

That vacuum solenoid manifold is pricey from HWH.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #17 – May 02, 2022, 09:02:18 pm

I believe NW RV Supplies has then for a lot less money.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #18 – May 03, 2022, 01:06:13 pm

Quote from: red tractor – May 02, 2022, 08:42:15 pm

That vacuum solenoid manifold is pricey from HWH.

Red, if I am not mistaken, the manifold is around $600. Was wondering if they would just sell the solenoid itself? Still don't know why it was leaking at the base and new O rings did not fix it.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #19 – May 03, 2022, 01:06:54 pm

Quote from: oldguy – May 02, 2022, 09:02:18 pm

I believe NW RV Supplies has then for a lot less money.

Will take a look, thanks for that comment!

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #20 – May 03, 2022, 07:04:01 pm

I tried fixing one of the manifolds and after numerous attempts had to get a new one.

Re: Aux Air Compressor running but will not deflate the bladder when extending!

Reply #21 – May 04, 2022, 08:00:54 am

NW RV Supply has the manifold for just over $650. Thought HWH was around the same? Still waiting on a call from them! Not good business practice at all in my opinion!

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