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Topic: What air line fitting do I need to connect coach to a air compressor? (Read 863 times) previous topic - next topic

What air line fitting do I need to connect coach to a air compressor?

My on board air compressor is leaking so it is plugged. The coach will leak within about 2 days and seat on the tires. I am not sure if this is ok.

I have a air compressor for nail guns, I want to be able to connect to the air line to supply air to the leveling system. Basically replace the onboard air compressor.

The line goes to the on board air compressor is 1/4. How can add a female quick connect fitting so that I can hook up with the air compressor.
I already purchased multiple air fittings, but haven't found one fitting does that yet.



I am not familiar with the air line fitting terms yet. It seems like I need a 1/4 compression fitting to 1/4 NPT adapter.

Before wasting time on buy and return, Can you point me to a fitting that can do that? amazon link would be better.

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1991 Grand Villa U300

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #1 –
The coach sitting on the tires won't hurt anything. I,m not sure exactly
what you are trying to achieve so I can't help there.
Peter and Frieda Morin
1999 36ft. U320 Foretravel
Build # 5436
1998 Suzuki Sidekick Sport

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #2 –
Disconnect the output fitting from the coach air compressor and match it to the fittings you have,would reccomend you repair the onboard air compressor and drier so you do not put wet air in your system,it's not good,work on finding and fixing some of the air leaks so it lasts more then 2 days,they all leak somewhat but yours seems excessive.Don't forget the onboard air compressor is
controlled by your air leveling panel,that will not work with the pancake compressor,better off fixing the leaks and just start the coach to get air,it will be dry.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #3 –
Quote from: oldguy –
The coach sitting on the tires won't hurt anything. I,m not sure exactly
what you are trying to achieve so I can't help there.
So sitting on the tires is okay? I have the same issue - when parked in my yard the auto leveling system lowers one side all the way down onto the tires while the other side stays up about 3".
1998 U295 36' No slides
Towing 2018 Jeep Wrangler
Previous rigs:
  1995 26' Fleetwood Flair
  1998 34' Fleetwood Bounder
  1997 40' Bluebird BMC
  1999 24' Winnebago Minnie Class C

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #4 –
Quote from: Running Odometer –
It seems like I need a 1/4 compression fitting to 1/4 NPT adapter.
Can you point me to a fitting that can do that? amazon link would be better.
Any air line fitting added to your coach should meet DOT specs.  Parker is the brand you want.

https://ph.parker.com/us/en/air-brake-d-o-t-compression-style-fittings-for-j844-tubing-nta/vs68nta-4-4

Parker Hannifin VS68NTA-4-4 Brass Air Brake-NTA Male Connector Fitting, 1/4"...

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #5 –
Quote from: Running Odometer –
I want to be able to...supply air to the leveling system.
Air added from a external compressor should be passed through some type of air dryer.  Several Forum members have installed a "T" (plus a female quick connect) in the air hose running from the engine driven air compressor to the air dryer.  If you use this method to connect your external compressor, the air will go through the stock air dryer and into the wet tank.  From there it will supply the leveling system.

Once you have installed a female quick connect fitting (somewhere) to add air to your coach, then all you need is a double male adapter to connect your external air compressor hose.  See photo below:

Note:  If you want to get fancy, put a 1/4 turn ball valve in the middle of the double male adapter.





1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #6 –
Quote from: Dan & Annie –
So sitting on the tires is OK?  When parked in my yard the auto leveling system lowers one side all the way down onto the tires while the other side stays up about 3".
Your parking spot must not be level - is one side is lower than the other?

The auto leveling system tries to keep the coach level to the horizon - not to the ground.  As the air bags leak off and the coach settles down, it will keep lowering the "high" side of the coach until air pressure in one of the front corners reaches <10 psi.  At this point, the "lower" solenoids on the other side will be inhibited, and the coach will sit "level" with one side 3" higher than the other side.  If the bags on the side that is 3" high continue to leak down, the auto leveling system will activate the HWH aux compressor to add air to the system as required to keep the coach level.

This is completely normal.  The system is working as designed.  Tires touching the top of the wheel well won't hurt anything.


1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #7 –
Don't know about Dunning Kruger but Dan does not have a problem,think he's just saying how his works,to get the authors
leveling to work when he is not around the coach,you need the onboard compressor to be working to work with the leveling
computer.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #8 –
It's very important to choose between the types of air couplers. In all the posts above, an industrial type is shown. I never liked these and use a shop type coupler instead. There are several styles so make sure anything you purchase matches Easy to make an adapter so you can switch between styles. A Quick Guide to Air Line Couplers and Plugs

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #9 –
See External Compressor Connection to Add Air to Wet Tank and Service Tanks

Connecting a compressor to the Aux Air connection only adds air to the leveling system (at least in my 2001 coach) and should have an air dryer or water separator before the connection to add air.

This Aux Air connection does not add air to the service tanks or to the HWH tank in the 2001 version.  It may in other years or if check valves are not functioning or other modifications have been made.

Make sure you understand how your air system works before doing maintenance or making changes.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #10 –

Thanks everybody, I learned a lot about air lines from the post here.

Is it really ok to let the coach seat on the tires directly?

For 91 U300, the on board air compressor is probably out of production already. I don't know if any rebuild kit still available.

As to the air dryer, I plan to buy this one.



It is cheap enough so that I can play with it.

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1991 Grand Villa U300

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #11 –
Quote from: Running Odometer –
Is it really ok to let the coach seat on the tires directly?
Yes, it is OK.  Just be SURE it is back at proper ride height (all 4 corners) before you move from your parking spot.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #12 –
Quote from: Chuck & Jeannie –
Yes, it is OK.  Just be SURE it is back at proper ride height (all 4 corners) before you move from your parking spot.


Thanks for confirming that.

As to rebuild onboard air compressor, I am surprised that nobody ever write a post here regarding the rebuild. The model no is
GAST 5HCD-10-M500X. I couldn't find any related information in this forum using the search function.

Searched online, the closest model no. is GAST 5HCD-10-M550NGX. Not sure if these are interchangeable, if so, it is darn expensive.

Trying to find the rebuild kit, it seems like GAST Rebuild kit K263 is for 5HCD, but it is expensive at $203 per kit. And it is recommended to service every two years. At this price, I can certainly buy a new air compressor every two years. No wonder nobody write up a post on this forum. It might make sense just to do replumbing a little bit, add air dryer and use a regular air compressor.

1991 Grand Villa U300

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #13 –
Quote from: Running Odometer –
It might make sense just to do replumbing a little bit, add air dryer and use a regular air compressor.
Some of us have done exactly that.  I have been using a permanently mounted 115V air compressor on our coach for years.  It is very handy to be able to pressurize the air system anytime I wish, without having to start the big engine.

I am on my third iteration of a "built-in" air compressor.  The first two (California Air Tools and Kobalt) both died due to the motors letting the smoke out...either because I picked cheap compressors, or because they weren't getting enough cooling air when running in the confined space.  You can read about my experiments below.  I am currently using a Makita MAC700 which seems to be holding up very well.

110V Aux Air Compressor Install

Amazon.com: Makita MAC700 2.0 HP Big Bore Air Compressor : Everything Else

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #14 –
Quote from: Chuck & Jeannie –
Some of us have done exactly that.  I have been using a permanently mounted 115V air compressor on our coach for years.  It is very handy to be able to pressurize the air system anytime I wish, without having to start the big engine.

I am on my third iteration of a "built-in" air compressor.  The first two (California Air Tools and Kobalt) both died due to the motors letting the smoke out...either because I picked cheap compressors, or because they weren't getting enough cooling air when running in the confined space.  You can read about my experiments below.  I am currently using a Makita MAC700 which seems to be holding up very well.

110V Aux Air Compressor Install

Amazon.com: Makita MAC700 2.0 HP Big Bore Air Compressor : Everything Else



I sure read your post regarding the onboard air compressor replacement multiple times. As always, very well written and informative .
I was wondering the longevity of your system, your C.A.T burned out. last post of that thread using a Kobalt. Now you are using the Makita 2HP, the Kobalt is broken too?

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
1991 Grand Villa U300

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #15 –
Kobalt suffered exact same fate - the motor burned up.  No flames - just stinky burned electric wiring smell and black smoke smudges.  I dissected the motor but could not see any obvious reason for failure.  Tossed the motor - kept the air tank and all the hardware for future projects.

I have the Makita sitting on the corner of our joey bed and connected with a short rubber air hose to my original copper tubing cooling loop and water/oil filter.  That way, I can open the storage bay door and slide the compressor out into the open air when using it.  Doing so will hopefully let it run cooler and live longer.  It is not very noisy - even when standing right next to it.

By manipulating a couple valves I can send the compressor output to either just the wet tank, or just the tire filler hose (50' spring loaded retractable reel), or both.

1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #16 –

You could use a Senco compressor. As I previously posted, the smaller 1/2 hp versions easily run on a 1500 watt inverter and put out plenty of pressure for almost any task without making too much noise. https://www.amazon.com/Senco-PC1010-1- Horsepower-1-Gallon-Compressor/dp/B0000AQK78  Makita would also be an option. Would be louder than OEM in the middle of the night.

Think I paid $25 and $40 off CL or FB Marketplace.

Pierce

As an Amazon Associate Foretravel Owners' Forum earns from qualifying purchases.
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #17 –
A 12v compressor option is one of these twin motor ARBs. Several are using them. I have one and am going to add it as a backup.  Pretty compact.  Comes with a nice wiring harness.
ARB 12V Twin Compressor | CKMTA12|Northridge4x4

You can get a $50 discount on your first purchase.
Roger Engdahl and Susan Green
2001 U320 3610 #5879 (Home2) - 2014 Jeep Cherokee or 2018 F150
Hastings, MN
 

Re: What air line fitting do I need to connect coach to a air compressor?

Reply #18 –
Quote from: Roger & Susan in Home2 –
A 12v compressor option is one of these twin motor ARBs. Several are using them. I have one and am going to add it as a backup.  Pretty compact.  Comes with a nice wiring harness.
ARB 12V Twin Compressor | CKMTA12|Northridge4x4

You can get a $50 discount on your first purchase.

Anyone find a similar discount? I am looking for air compressors that I can buy online for my car. I would be very happy if someone could help. ;)