88 s10 when i hit the front switch the motor pumps but the truck lifts about an inch thats it. then about twenty minutes later the truck is back down, if i jack the front up with a car jack hit the switch then let the jack down the truck stays up for about 20 minutes.help is greatly appreciated. my set up is two pro hopper pumps 4 dumps 4 solinoids 6 batteries.thanks.