JRZEE2000TR4LTD
Senior Member
That is exactly how you do it. That one piece of tubing going to the pressure switch needs to be removed/ closed off. Just make sure you use the open chuck so the pump stays loaded until your done using it.
Air compressor help
- Thread starter kolelt
- Start date
That is exactly how you do it. That one piece of tubing going to the pressure switch needs to be removed/ closed off. Just make sure you use the open chuck so the pump stays loaded until your done using it.
Run a T fitting right of the compressor ? On one end of the T the pressure switch goes ? Then the other end is the line wheee you hook up the air hose ?
Run a T fitting right of the compressor ? On one end of the T the pressure switch goes ? Then the other end is the line wheee you hook up the air hose ?
So every wire on the relay side can be thin wires? Even for. The pressure switch ?
To be honest I have no idea how to do this properly.
Last edited:
Roc Doc
New member
Oh, and run it with the engine running and idle up to 2000rpm or so and that should get you 13-14v which will lower the current draw.
Made this a few years ago. Viair compressor, 12v exhaust fan, Pep Boyz filter. Holds the chuck with gauge, 25' hose, compressor, 20' power cable and deflators.
Made this a few years ago. Viair compressor, 12v exhaust fan, Pep Boyz filter. Holds the chuck with gauge, 25' hose, compressor, 20' power cable and deflators.
Viair compressors run into an open fitting, and they assume you'll setup proper supporting hardware (like a pressure switch) depending on your application.
The pressure switch is unrelated to the tank, it simply has an air input where it senses pressure and an optional unloader port that releases pressure at the compressor output so that it doesn't have to re-start under load.
If you run all open fittings and are only ever going to inflate tires then you don't need a pressure switch. If there is ever any possibility of a closed system that can build pressure then you need a pressure switch.
- Matt
JRZEE2000TR4LTD
Senior Member
This is all true except the pressure switch not being related to the tank. The tank is where the pressure switch is reading it's pressure and cycling on and off, probably with a 30-35psi differential. Also, the unloader is not optional if using a tank.
OP, since your not using a tank, you will not be using a pressure switch. You will have to use an open chuck which hopefully flows more than the output of the pump. A bulletproof setup would be your air output going into a brass 4 way. One side is from the pump, one side is your hose coupling (male), one side would be an open valve, and one side would be a safety pop off valve rated for 90 psi. You start the compressor with the valve open, acting like an unloader, and close it when your ready to use it. You'll still need an open chuck because once you close the valve, it will build pressure too fast if you used a closed chuck. Now if you find the open chuck will flow enough pressure that there wont be any pressure build up then you can go with a tee fitting and do away with the valve. I think that will be the case.
Roc Doc
New member
I use closed chucks in the above setup, but don't power it up until the extension hose is connected and I'm ready to use it. The pressure builds up a bit in the hose as I'm moving from tire to tire, but I've been doing it this way for years with no issues. I know this discussion includes a tank, and they're definitely an asset, but not entirely necessary if you're just going to be inflating tires.
Pressure isn't only found in a tank and a pressure switch can be mounted anywhere to switch a compressor on and off. My CJ has the tank mounted under the floor of the Jeep and my pressure switch is in the engine compartment. The ARB compressors come with a pressure switch whether you use a tank or not as they are intended to be used in a dead headed system (air lockers).
What people seem to be forgetting is that a pressure switch not only turns the compressor on and off, but it can be a safety device to prevent overpressurization if the user becomes distracted while using or the fill valve doesn't have the ability to bleed off pressure as fast the compressor builds it or any other oddball scenarios that have the possibility of happening.
No, you don't absolutely have to have a pressure switch, but for $10 and a couple extra wires I don't see why you wouldn't use one.
TheDurk
Elite Member
This, plus the point that, if you ever want to try to run an air tool with it, the pressure switch is a must. Obviously, continued air tool use needs a tank, but to bust one nut loose with an impact on the trail, you can probably do that if the system is protected from overpressuring while the impact is connected.
I wouldn't buy a compressor that won't start under load, nor would I install one without a pressure switch, tank or not. Any compressor that has a pressure switch will continuously cycle between the off/on pressures of the switch, and has to be able to deal with that cycling just like the compressor in your garage. The only thing the tank does is slows down the rate of cycling and gives more reserve for things like air tools.
My VIAIR 400C operates just fine with a pressure switch and no tank. The pressure switch makes it a pretty fool proof operation.
My VIAIR 400C operates just fine with a pressure switch and no tank. The pressure switch makes it a pretty fool proof operation.
The pressure switch is truly unrelated to the tank, it can just as well measure pressure off of a hose on the output of the compressor (acts like a very small tank). The unloader is optional. It is used in cases where you have a one-way valve after the compressor to prevent backflow through the valves in the compressor head. The unloader releases pressure between the compressor and the one-way valve so that the compressor can re-start without being under load.
My OBA setup does not have a tank, but since I have closed fittings that create a sealed system I have a pressure switch. When the compressor is turned on it runs for a second or two, pressurizes the hose, and then turns off. When I hook up the hose to a tire it turns back on and fills the tire. The pressure switch makes sure I never pressurize the hose over ~120psi which protects the hose and the compressor.
On Board Air (OBA) - Blank White Page
- Matt
UPDATE
Extended the wires with 8 gauge wire. It worked out perfect because the wires I got of eBay were already glued together.
I then wired in a 50amp breaker.
And installed my own battery clips.
I believe everything was like $10-15
I kept the breaker closer to battery.
Right here I made own open air chuck. Got a free ARB tire pressure gauge thing. But it had a lever to release the air so no good for me. I took the hose of ( open air chuck) went to Home Depot got a gauge, and few adaptors to make everything work. Actually works good. Even the gauge. Only thing is the gauge is little of when pumping but I have a digital one to double check where I am on PSI. With the compressor running and open air chuck hooked up. The gauge is a hair line above 0. So no pressure is being built up.
Extended the wires with 8 gauge wire. It worked out perfect because the wires I got of eBay were already glued together.
I then wired in a 50amp breaker.
And installed my own battery clips.
I believe everything was like $10-15
I kept the breaker closer to battery.
Right here I made own open air chuck. Got a free ARB tire pressure gauge thing. But it had a lever to release the air so no good for me. I took the hose of ( open air chuck) went to Home Depot got a gauge, and few adaptors to make everything work. Actually works good. Even the gauge. Only thing is the gauge is little of when pumping but I have a digital one to double check where I am on PSI. With the compressor running and open air chuck hooked up. The gauge is a hair line above 0. So no pressure is being built up.
