my air dog and it will hold pressure but when on the throttle hard it losses a lot of psi and goes below 5 and sometimes 0. But when at 75mph it sits at 10 psi but hit the throttle it goes down. Could it be the ball and spring stuck slightly? Thinking it is taking a crap on me and was wondering what to buy next another air dog or go with fass or a mechanical pump? Money is not to tight right now but with it being my DD I don't want to be down this winter sitting on the side of the road when it goes out.

If mechanical pump would I be able to use the air dog filters down on the frame still?

How old is the airdog? What model is it? It sounds like you might just have a restriction in the line somewhere. Most of the pump failures I have heard of will either just stop working, or slowly lose pressure and eventually stay at 0 psi because the pump gets to hot internally. If it has an adjustable regulator, have you tried turning up the pressure at all?

Definitely sounds like the ball is hanging open on the return. Pull it apart and have a look. Mine did it once and the ball was actually wedged into the spring.

I have the FUEL BOSS and I have been extremely impressed by it.  By pressure sits at 17 PSI and doesn't move.  A lot of people claim that their pressure will increase with throttle but my stays solid and that is due to the bypass valve.  My pressure used to be all over the place before I installed the mechanical lift pump, I don't worry about it now.  If your Air Dog is done for, I would certainly recommend the Fuel Boss, it only took me a couple of hours to install.

You need to pull the regulator apart and see if you can find anything. If you have an adjustable regulator, you need to set it between 18-20 psi.

 

Take your spring and slightly egg shape the last coil the ball is going to sit on. Then the very tip say 1/8 of the bend in a 90* angle inwards to the coil so the ball can't wedge down into the coils.

Ok I'll look at the spring today or tomorrow. The air dog is about 2 years old. The spring and ball is on the return hose? Best way to get at it on the frame?

Ok I'll look at the spring today or tomorrow. The air dog is about 2 years old. The spring and ball is on the return hose? Best way to get at it on the frame?

 

Well I can't answer how to get at it really my AirDog is not on the frame. But yes it's in the return line just take the fitting out of the pump and the spring and ball are just inside the housing of the pump. Mine is the forward fitting on the rail side. I typically use a 3/4" wrench remove the JIC elbow and then a deep well socket remove the fitting.

 

Jarren at Airdog told me that a machining issue in the pump bodies causes the Orings in the regulator to get cut and leak, thus causing issues with pressure drop.  Of the 4 Airdogs I had fail 3 of them started to show very bad pressure drops before they kicked the bucket. 

 

I would call Airdog.

yup ball was wedged into the spring a bit and tested it now and it seems to be working alot better. will know more when i get the new glow shift style fuel pressure gauge installed

Good luck with the glow shift. Had nothing but problems with them in my personal pickup and another customers pickup

I have had really good with the pyro and boost one but the fuel pressure one is trouble. the old style has a diaphragm style electrical one and the new one doesn't so hope the vp44 doesn't hammer it as hard even with the snubber valve on it