Brake booster problems
So anyway hello everyone, having just joined if I put this in the wrong spot let me know.
I have a 2008 f150 with not that many miles 75,000 roughly. The other day the brakes began to drag a little and when I left and got back in the truck the pedal was right at the top. There wasn't any vacuum in the booster. So I come back home put a vacuum pump and gauge on it and I can pump it down and watch the pressure go back up fairly rapidly. It looses all vacuum in about 3 minutes. So I figure for whatever reason it went bad, and I replace it. Now the new one is doing the same thing and it's driving me crazy. The check valve should stop this from happening and I assume everything is good on the new one, at least I would hope. So any ideas what's going on here, and to nip the bud so to speak no it's not supposed to be like that. I have access to another 08 f150 and it will hold vacuum almost indefinitely. Any help would be greatly appreciated.
I have a 2008 f150 with not that many miles 75,000 roughly. The other day the brakes began to drag a little and when I left and got back in the truck the pedal was right at the top. There wasn't any vacuum in the booster. So I come back home put a vacuum pump and gauge on it and I can pump it down and watch the pressure go back up fairly rapidly. It looses all vacuum in about 3 minutes. So I figure for whatever reason it went bad, and I replace it. Now the new one is doing the same thing and it's driving me crazy. The check valve should stop this from happening and I assume everything is good on the new one, at least I would hope. So any ideas what's going on here, and to nip the bud so to speak no it's not supposed to be like that. I have access to another 08 f150 and it will hold vacuum almost indefinitely. Any help would be greatly appreciated.

