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What will cause a cooling system to pull a vaccume

rioncrsn ยท 2015-01-17 20:53

got a cummins that flows only when radiator cap is off, when cap is put back on it stops flow, what could cause this?

Replies4
  1. #1Delmer2015-01-17 22:06

    I don't know, but I can't wait to hear the explanation for this one! How do you know the flow stops when the cap is on? and how do you know the cooling system is pulling a vacuum? Have you pressure tested it?

  2. #2GregsHD2015-01-18 14:03

    Did you just drain and refill the cooling system? Possible airlock? When the cap is on it's not letting it burp? Need more info...

  3. #3Muffler Bearing2015-01-19 13:07

    yeah, does it pull the vacuum after it's cooled off from being hot? and the hoses are collapsed?

  4. #4AllDodge2015-01-19 13:48

    How do you know the flow stops?