Posted January 25, 201114 yr 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.
January 25, 201114 yr 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.
January 25, 201114 yr 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.
January 26, 201114 yr Author :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?
January 26, 201114 yr 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?
January 30, 201114 yr Owner 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...
January 31, 201114 yr Mine does it too. I have a Glow Shift fuel gauge and have a needle valve in line also.
January 31, 201114 yr 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.
January 31, 201114 yr 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.
January 31, 201114 yr 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.
January 31, 201114 yr Author It does not do it just slowing down, you need to apply good pedal and you can get 1 1/2 pound rise.
January 31, 201114 yr 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.
February 1, 201114 yr Author 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.
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.