Your going to think I am crazy, but what would make your fuel pressure go up when you hit your brakes. Pressure runs steady 17psi hit the brakes and it goes up to 18.50 almost 19.:shrug:It has done this since I replaced my airdog 100 with the 150.

Um bad ground?!?

Full tank, half tank, or empty tank?????? If it happens more as your fuel gets lower, it could be something along the lines of that your draw straw/pickup tube is too short or is moving around in the tank.Your gauge could be going out. When you slow down/hit the brakes, does the gauge needle fall in the direction of the front of the truck???Could be a bad ground like said above that is affecting the pump itself.......or if electrical gauge it could be affecting the sender.

the only time i had a problem with my airdog, was when the corrosion on the battery terminals was bad enough to give a weak connection. i don't have a gauge in the cab, so it may be normal.

:shrug:It does itfull, empty it dont matter. It is a manual gauge. I been thinking about it and I wonder if a air bubble in the line would cause this? The line is coming off the pump and it is running along the side of the frame rail, if it had a bubble along the frame and when you apply the brakes gravity would push forward?

i guess thats a possiblity but i found when my fuel pressure was doing funky crap like that it was water hammer. do you have a fuel snubber or needle valve installed?

It's a a a a regulator I cant remember what you call it.

did u get her figured out JL?

Ummm... If I'm not missing something but AirDog is a lifetime warranty...Why not give good old Pureflow a call and see what they say...

Mine does it too. I have a Glow Shift fuel gauge and have a needle valve in line also.

Does it happen everytime you hit the brakes, like stopped? Or does it happen as you decelerate? My pressure goes up as I decelerate, the harder I brake the higher the pressure. I run about 8-9 normally, and can get 11-12 if I stop quite quick. If its that then its normal.

i noticed today under heavy braking mine dropped down to 7 then right back up to 15. and it stays anywhere between 14-15 while cruising down the highway.

its the brake lights sucking up all the electricity:lmao:but seriously, when my airdog wasn't moving much fuel, it was cause it had trouble getting power(corroded battery terminals). could you(would you wanna) wire a volt/amp gauge at the pump so you could tell if it was a power issue.

It does not do it just slowing down, you need to apply good pedal and you can get 1 1/2 pound rise.

It does not do it just slowing down, you need to apply good pedal and you can get 1 1/2 pound rise.

Sounds normal.. guess your building some -G's.

Yea it sounds weird, my AD 100 didnt do it and the pressure line is in the same place. The air bubble thing is all I could come up with. I will try to bleed it and keep you posted.