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Need help with air hook up on my TSLB hitch


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Hey guys,

I wasn't really sure where to post my question but figured this group would have the knowledge I need. I have a used TSLB trailersaver hitch installed on my truck but the hitch didn't come with anything necessary to hook up air to it.

The people who installed my hitch to the bed of the truck installed a switch on the dash and tied it into my truck air supply system. But the switch was an old faulty switch that doesn't hold air (will leak down)....and they had no knowledge of this model hitch and how to hook it up. 

Can I get some advice/tips on what I need to do and/or what parts I need to purchase to make the two air bags function? I'm not familiar with how to install the system, I took it to my mechanic and he said he doesn't know anything about it.... but he said if I could get him the parts and some instructions he might could help me out.

Do you guys have your hitches tied into the truck air supply? Where can I purchase a new switch? Do I need any type of pressure gauge?

Thanks for the help,



2000 American Coach Heritage 45' motorhome

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There are many different ways to do this.  Having recently installed a TSLB I can tell you how I did it, but that doesn't mean it is the best way.

I put a "T" in the 1/4" airline that goes to the cab leveling valve.  From that "T" I ran 1/4 inch DOT nylon airline to a pressure regulator with a gauge near the connection to the TSLB.  I manually adjust the regulator to provide enough air pressure to lift the bags to the white mark on the hitch once I am hooked up.  Some of the guys use a leveling valve like the one used with your cab air bags connected to the back of the hitch that is adjusted to maintain a constant height.  Others simply put a Schrader valve on the airline going to the airbags so they can fill and forget.  The reason I tapped the airline going to the cab leveling valve is because it is one of the last lines to come up to pressure.  If the line should leak or break your air loss would not be enough to impact air needed for braking.  The dash switch system is usually installed on PU trucks that need an auxiliary air compressor.  You can download a full installation and useage manual from the Hensley web site.


Randy, Nancy and Oscar

"The Great White" - 2004 Volvo VNL670, D12, 10-speed, converted to single axle pulling a Keystone Cambridge 5th wheel, 40', 4 slides and about 19,000# with empty tanks.

ARS - WB4BZX, Electrical Engineer, Master Electrician, D.Ed., Professor Emeritus - Happily Retired!


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Mine is hooked to the 5th wheel slide switch on the dash and like Randy did with a regulator. Air line was already in the frame rail for easy access and I can dump the air to hook/unhook.

1999 Peterbilt 385 C12 430/1650 13spd

2006 Dodge 3500 DRW 4x4

2010 Hitchhiker Champagne 36 LKRSB

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I did like CrazyCooter, but with a leveling valve rather than a regulator.  Works great, and as he pointed out, I can dump it for hitching maneuvers.

Newmar X-Aire, VATICAN
Lots of old motorcycles, Moto Guzzi Griso and Spyder F3 currently in the front row
Young enough to play in the dirt as a retired farmer.
contact me at rickeieio@yahoo.com

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All way too complicated...

All you need is a manual air paddle switch like this for $26:


Or you can get it in a panel with a gauge for $68:


That is an AIR paddle switch and NOT an electrical switch.  Has 1/4" nipples on the back to plug the airline right in.  Simple and easy.  No wiring, fuses, connections or anything else to fail. 

All you need to do is tee into your 1/4" air supply line as others have noted above.  Run the 1/4" line to the paddle switch, then back to your hitch.  All of the parts you will need are:

switch or panel above
roll of 1/4" airline
3    1/4" airline tees (one to tap in to your supply, one to feed the gauge, one to split to both air bags on the hitch)

On my truck I cut a square hole to snap the switch into in the dash low on the drivers side where I could reach it either from the drivers seat to adjust on the fly or from the ground to inflate or drop the air without crawling back in the truck.  Then I put the gauge in an existing round knockout in the dash.  Or you can just bolt that whole panel to your dash.

No regulator required, once you hitch up and level it to the white line once, just note the pressure on the gauge and set to that pressure whenever you hook up.  Unless you significantly change the pin weight of course, then you need to recheck your pressure to get level.  I actually don't like the idea of a regulator or leveling valve in the system, just adds one more thing to fail.  Plus I can overinflate the hitch if needed hooking/unhooking/leveling the trailer.  Also I can adjust on the fly, if we are on a bouncy stretch of road and it seems like the trailer is getting a lot of movement I can pump up the air a bit to firm up the hitch, and let it back out when the road smooths out.

Here is a link:


They also have all the fittings and line, but air line is usually cheaper at your local semi parts counter.  No connection to them other than we used to buy our parts from them back when we used to build air ride suspensions in our shop.

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