Cooling system will not hold vacuum

Steve Mutter · August 1, 2014

I have 2005 6.0 that will not hold vacuum when trying to fill the system. I have just done the head gaskets, pressure tested the egr cooler(ford egr cooler) when it was off and found it not leaking and re sealed the front cover. I can hear it gurgling in some of the rad hoses but have had no luck yet finding the leak so I put pressure on it still nothing yet. Do you guys have any tips for trying to find a leak that only leaks when vacuum is pulled on a system.

scott1984 · August 1, 2014

I know this sounds crazy but is the petcock in the radiator fully closed. Also check the intake and make sure its down all the way. Had one get me last ego cooler I put in. And one that note I vacuum test the ego cooler not pressure test. I had some pass the pressure but it fail the vacuum test.

Steve Mutter · August 1, 2014

_{I removed the intake and blocked off the open coolant lines and it still would bleed down,blocked off the upper and lower rad hoses and it still bleeds down. So the only thing left the has a o-ring seal is the water pump so I put a new water pump in and that was it. It now pulls to 25 inch's and holds pressure. Thanks}

Matt Saunoras · August 1, 2014

Wow, was there any sign of the pump leaking?

Steve Mutter · August 2, 2014

Nope, bone dry. It's hard to tell but I think the seal that seals too the front cover it's the one that was leaking, nonetheless a new pump was put in and all is good.

mchan68 · August 3, 2014

I had one a while ago that I long-blocked, that was leaking coolant from that seal after I drove it home for a night. Of course, it would help if the water pump was installed WITHOUT cocking the seal between the water pump and front cover.

CISCO · August 28, 2014

I HAVE HAD 2 WATER PUMPS LEAKE AFTER EGR/OIL COOLER REPLACEMENT WHEN USING AIRLIFT TOOL. I THINK THAT IF WATER PUMP IS BORDERLINE, IT WILL FAIL COMPLETELY WHEN USING AIRLIFT TOOL.