Inexpensive ARB Air Locker Bench Tester (1 Viewer)

[ArmyFJ]

So I stumbled on this while trying to figure out a way to bench test my ARB lockers and wanted to share.

It turns out that the female fitting at the end of a Harbor Freight air blow gun (I assume other brands as well) is 1/8 in. BSP. So the 6mm press fitting to 1/8 in. BSP coupler that comes with the locker will tread into the blow gun. I put this in line with an air flow regulator to push ~80 PSI to the locker. Worked perfectly! Cost was about $12 vs. $85.

 

[landcrshr]

Cool setup.

I'm pretty sure the 1/8" end of the gun is NPT. It works because the difference is only 1 tpi., and the loose interface due to straight threads vs. tapered threads, which is Ok because the ARB fitting seals with an O-ring.

I discovered this when I added 1/8" tees for my pressure switches. I did have to re-tap the Solenoid for NPT though.

 

[ArmyFJ]

Cool setup.

I'm pretty sure the 1/8" end of the gun is NPT. It works because the difference is only 1 tpi., and the loose interface due to straight threads vs. tapered threads, which is Ok because the ARB fitting seals with an O-ring.

That makes perfect sense. It just fit so nicely I assumed it must have been BSP.

 

[inkpot]

I used one of those air guns as a controller for the airhorns in my FJ 55. Made it real easy to do the wa-Wa-WAAAAAAA train horn thing!

 

[NLXTACY]

Yup, at 1/8 NPT and BSPT are nearly identical. It doesn’t match any larger than that. But the blow gun will almost always be NPT.

 

[Dindu Nuffin]

You'd think it would be BSP, since BSP is the oddball metric of pipe thread, and HF likes using weird s*** like 13mm bolts or throwing a couple 1/2" nuts in with the bag of 12mm nuts.

 

[PabloCruise]

It takes 80 PSI to cycle an ARB? I didn't think it was that much!

 

[Cruzerman]

It takes 80 PSI to cycle an ARB? I didn't think it was that much!

I too thought it was less, but this is from the ARB site:

WHAT IS THE MINIMUM AND MAXIMUM AIR PRESSURE REQUIRED TO OPERATED AN ARB AIR LOCKER
The ARB Air Locker will engage at around 70 PSI. However, for faster engagement and disengagement, we recommend an air pressure supply between 100 and 150 PSI.

 

[jonheld]

I too thought it was less, but this is from the ARB site:

WHAT IS THE MINIMUM AND MAXIMUM AIR PRESSURE REQUIRED TO OPERATED AN ARB AIR LOCKER
The ARB Air Locker will engage at around 70 PSI. However, for faster engagement and disengagement, we recommend an air pressure supply between 100 and 150 PSI.

I ran ARB lockers for years in my 91. I had a York OBA system and used a second regulator for the lockers. They would reliably lock in all conditions at 68-70 psi.
The high pressure cutoff switch that ARB used to supply was VERY inaccurate and I blew out a rear locker seal. After getting that fixed, I made my own system and it was reliable for many years.

 

[use2bn83]

So I stumbled on this while trying to figure out a way to bench test my ARB lockers and wanted to share.

It turns out that the female fitting at the end of a Harbor Freight air blow gun (I assume other brands as well) is 1/8 in. BSP. So the 6mm press fitting to 1/8 in. BSP coupler that comes with the locker will tread into the blow gun. I put this in line with an air flow regulator to push ~80 PSI to the locker. Worked perfectly! Cost was about $12 vs. $85.

While I see this would work for actuation, it doesn’t seem to do anything for checking leakdown unless I’m missing something.... cool idea.

 

[ArmyFJ]

While I see this would work for actuation, it doesn’t seem to do anything for checking leakdown unless I’m missing something.... cool idea.

I suppose you're right. That said, you could just close the compressor valve and see if it looses pressure. But that would assume there are no leaks in the gun.

 

[I Lean]

Here's my well-used pressure tester. The lens on the gauge got all hazy when I got some brake cleaner overspray on it.