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aux air compressor for air leveling


grizzly
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1 hour ago, grizzly said:

I don't believe I ever said it was by the rear drive axle. I did state the airline looks like it goes into frame and goes to bank air tank. Always have know it was in the front behind the axle. Sorry if I stated that. And yes it is a power gear valid system which I also thought I stated somewhere. No manual came with coach on that unfortunately

 

No a line plastic line coming off the compressor and then run up to by main air tank with a filter. I am thinking it was put there to keep it out of the moisture from road and junk.

I have a check valve on the output of the compressor before it goes into a tee. So there is also an internal check valve also?

I still need pictures.  

What you are saying doesn't match how that compressor was installed by Monaco from the factory.  There was an early post by someone with an 07 Signature showing a picture of the compressor mounted just ahead of the drive axle.  Please post a picture of your setup and look to see if you have the rear small air tank.

BTW, on your system that external check valve and a remote relocation of the air intake is not OEM.  That begs the question whether those modifications also included a replacement compressor. We also now need to know if that small rear tank was also modified.  Pictures will tell us.

Pictures please of both your compressor AND the rear air tank.

Attached is a copy of your owners manual.

2007_Signature.pdf

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1 hour ago, 96 EVO said:

Cool!

I'm going to do the same when it warms up a bit.

After seeing yours, I'm 99% sure that's where my leak-by issues come from.

I think you'll find dirt in that chamber and on that o-ring.  I did not need to replace any gaskets.  Just be careful to look at how the reed valve is installed.  There are 2 metal parts held in place by a screw.  The lower one is the flexible metal reed valve that sits on the o-ring when the output chamber is under pressure.  The other metal part is stiff with a slight upward bend and it allows the reed valves to flex up but just a bit to let compressed air in.  Remember to reinstall both parts correctly.

Yes, I'm sure this will fix your problem.

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1 hour ago, Frank McElroy said:

I still need pictures.  

What you are saying doesn't match how that compressor was installed by Monaco from the factory.  There was an early post by someone with an 07 Signature showing a picture of the compressor mounted just ahead of the drive axle.  Please post a picture of your setup and look to see if you have the rear small air tank.

BTW, on your system that external check valve and a remote relocation of the air intake is not OEM.  That begs the question whether those modifications also included a replacement compressor. We also now need to know if that small rear tank was also modified.  Pictures will tell us.

Pictures please of both your compressor AND the rear air tank.

Attached is a copy of your owners manual.

2007_Signature.pdf 19.63 MB · 1 download

I will try to get pics of front set up tomorrow if not raining. Rear will be a little harder and maybe longer, Thanks for the help

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1 hour ago, grizzly said:

Thank you for posting these pictures.  Your compressor is different than mine and looks very similar to the older HWH compressor without the air dryer.  I don't believe this compressor has an internal check valve.  That's why you have an external check valve at the compressor outlet.  However, maybe someone who has removed the head from this compressor will chime in and let us know if they were able to dismantle the head and what they found inside.  Maybe dirty reed valves not seating properly.

On the outlet tee, one end goes to the air pressure switch and the other end feeds a small rear air tank exactly like the one I have.  I also see a red color connection on that air line from the compressor to this tank.  That red connector is a check valve.  I included a blown up picture of the one you sent showing that red connector.

Now, this thread all started with you saying that the aux compressor runs a long time.  How long is long.  The compressor will need to run long enough to refill that small tank.  Also, how frequently does it run.  

Depending on your reply, it might be necessary to measure air pressures on the compressor outlet to be sure the pressure switch is functioning properly.

If the check valve at the compressor is bad, you would likely have short cycling and frequent running multiple times an hour.

Another possibility for long run times is a clogged air filter or a worn out compressor. 

But first, please post how long your compressor runs when in auto level mode and how often it runs.

Screenshot_20230214-153758.png

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Have a question. On that blown up pic with red on it, there is a little ring on a valve . Is that a drain or a pressure relief valve? I ordered a new pressure switch and check valve for up front today. I have had the compressor shut off for a couple of days and turned it on awhile ago and it ran for 25 plus minutes and never shut off. First time that has happened . Usually about 10- 15 minutes then shuts off. But would come back on maybe 5 times a day. Does the back main air tank feed the smaller tank? I ask because my rear main tank is loosing air slowly whereas my front main tank doesn't loose air. I assume the big main tanks feed the smaller tanks? Or am I wrong on that? Because if motor is running on engine I can level the coach how ever I want to

Could the check valve o9n rear tank be bad? Also I wonder if compressor is wearing out?

The Valid tech said if moisture got into compressor it would start to fail

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20 minutes ago, grizzly said:

Have a question. On that blown up pic with red on it, there is a little ring on a valve . Is that a drain or a pressure relief valve? I ordered a new pressure switch and check valve for up front today. I have had the compressor shut off for a couple of days and turned it on awhile ago and it ran for 25 plus minutes and never shut off. First time that has happened . Usually about 10- 15 minutes then shuts off. But would come back on maybe 5 times a day. Does the back main air tank feed the smaller tank? I ask because my rear main tank is loosing air slowly whereas my front main tank doesn't loose air. I assume the big main tanks feed the smaller tanks? Or am I wrong on that? Because if motor is running on engine I can level the coach how ever I want to

Could the check valve o9n rear tank be bad? Also I wonder if compressor is wearing out?

The Valid tech said if moisture got into compressor it would start to fail

I left you a voice mail message with my cell number to call me back.

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  • 4 weeks later...
On 2/13/2023 at 8:35 PM, Frank McElroy said:

I think you'll find dirt in that chamber and on that o-ring.  I did not need to replace any gaskets.  Just be careful to look at how the reed valve is installed.  There are 2 metal parts held in place by a screw.  The lower one is the flexible metal reed valve that sits on the o-ring when the output chamber is under pressure.  The other metal part is stiff with a slight upward bend and it allows the reed valves to flex up but just a bit to let compressed air in.  Remember to reinstall both parts correctly.

Yes, I'm sure this will fix your problem.

Did Frank's head off cleanup today.

Yes, there was corrosion in there! I'd really like to have removed that little 'O' ring, and cleaned the groove out, but couldn't guarantee I could get it out without damaging it, and then possibly not being able to find a replacement!

I know it's not leaking back now cause I charged the tank and put my finger over the intake hole. No air releasing!

I'll check my coach tanks in 24hrs. I 'think' most will be surprised how much air that little compressor can leak out of an air system!

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Well, made a bit of difference!

I lost 6psi from my chassis tanks in the last 24hrs, since cleaning up the reed valve in the aux compressor head.

Previous 24 hrs before the work, I lost 70psi from the chassis tanks, and all air from the small leveling tank.

I think it was worth the hours work!

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3 hours ago, 96 EVO said:

Well, made a bit of difference!

I lost 6psi from my chassis tanks in the last 24hrs, since cleaning up the reed valve in the aux compressor head.

Previous 24 hrs before the work, I lost 70psi from the chassis tanks, and all air from the small leveling tank.

I think it was worth the hours work!

Thanks for the update.  Makes sense and glad it helped solve your problem.

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Appreciate you tearing into yours when you really didn't need to!

I never would have thought these pumps would have a simple, easy to service, reed valve.

Probably would have just tossed the compressor, or maybe installed a check valve on the output.  

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It's a good thing you cleaned the internal reed valve.  If you installed an external check valve, the air volume between the external check valve and the piston head would have significantly lowered the maximum output pressure of the pump.

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1 hour ago, Frank McElroy said:

It's a good thing you cleaned the internal reed valve.  If you installed an external check valve, the air volume between the external check valve and the piston head would have significantly lowered the maximum output pressure of the pump.

Guess I’m going to have to think about the lower pressure???

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1 hour ago, Ivylog said:

Guess I’m going to have to think about the lower pressure???

The air chamber in the head between the exhaust reed valve and an external check valve is large compared to the piston compression stroke air volume.  If the reed valve is significantly leaking, the compressed air in the exhaust chamber behind the external check valve would leak back into the cylinder on the air intake stroke.  This in effect lowers the efficiency of the compressor and it's maximum output pressure.  If the leak is tiny, you likely wouldn't notice an issue but a large leak is a problem.

So, on compressors with head reed valves, the preferred solution is to clean or replace the reed valve and seat vs adding an external check valve. 

There are other compressors designed with external head check valves but the internal exhaust chamber is just a small bore to the external check valve - no large air chamber to house an exhaust reed valve.

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1 hour ago, 96 EVO said:

Wonder how many shop's have been stumped by that little reed valve leaking bye!

Charging customers thousands, changing out PPV's and air lines.

I'll bet it's happened!

Yes, unfortunately and sadly you are correct.  It also reminds me of issues with the smart wheel on chassis multiplex coaches where one person paid $2K for a $20 repair.  However, in fairness, not all shops can be knowledgeable on all repairs.  That's why owners need to do their research on internet forums where subject matter experts often post repair solutions to challenging problems.  

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Guest Ray Davis
8 hours ago, Frank McElroy said:

That's why owners need to do their research on internet forums where subject matter experts often post repair solutions to challenging problems.

Yep, and this is the best forum for that.   Unfortunately,  on one of the other forums,  it's not always easy to tell folks about Bill D's Monacoers.   

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Several coach owners on another site have installed a Jun Air Compressor, used by dentists. Whisper quiet @ 45db. You will have to call Jun to have them recommend which model they would recommend for YOUR application. About 1K$. , as i recall.

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Decided to remove and inspect my aux compressor from behind the front axle because it took for ever to build pressure and it’s very noisy. All of the inside is black due to poor filtering of the air and the cylinder is scored badly. Honed it and sanded the lip of the piston. Still just as noisy and I’ve already mounted another compressor up front next to the generator. Has to be a better location and it’s a lot quicker than the Power Gear.

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  • 7 months later...

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