Ditto on the vacuum leak. My 98 Ram had the leak under the battery tray also. Also messed with my cruise control. Bear to get at without removing battery tray though.

 

Yes, you all are correct. I had a 97 Grand Cherokee that had the exact same problem. I $5 check valve fixed everything. After that I had A/C uphill at any speed. My dream come true LOL.

 

I have the same problem and I've checked everywhere for a leak and can not find one. I still have cruise which works really well. I hope there isn't a hole in one of the lines inside the cab, in the dash. That would be a pain.

 

how did you check it. By eye? Sometimes you cant always see the cracked line. try spraying carb cleaner on the lines, with motor running,and if the motor changes idel (ie.revs up or drops rpm) then you have found the leak.

 

I just tried that and I got nothing. Truck was running and I sprayed the lines and it did not change the idle at all. The only one I did not do was the one below the battery tray where the cruise is. I didn't do that one because I have cruise so I don't think it's that line. So I can't find the leak in the line so anyone else have any other ideas? Would it probably be just the check valve?

 

I would say, if all lines were checked and ok, that the valve is probably your next step. Its cheap, so go for it.

 

Anyone got a part number for the check valve?

 

I replaced the check valve but it still does it. And I checked for leaks and I couldn't find any.

 

Does this cause it to make a loud POP noise then shoot air back out at you. Mine does that it randomly picks when it wants to work..

 

mine pops also, i checked and i found no leaks, replaced the check valve and it still does it