Discussion:
Air/Propane bubbles in coolant

Hi Guys,
I have an issue on my Komatsu FG25-14 forklift. When I remove lid on the expansion tank I see bubbles of air or propane coming up. The oil is clean. I haven't looked into compression in the cylinders as oil is looking good. I thought it was a vaporizer, but replaced main parts in it and it still does the same.
Any ideas?
  • Posted 18 May 2019 14:44
  • By shawn_v
  • joined 18 May'19 - 1 message
  • New Jersey, United States
Showing items 1 - 3 of 3 results.
Head gasket is blown. Head gasket is blown in a spot between 2 of the cylinders and blowing compression back into the radiator. You won't see water in the oil or oil in the water and it can still be a blown head gasket. I have seen it a lot. Good luck!
  • Posted 22 Jun 2023 13:39
  • By Persley
  • joined 24 Jun'19 - 7 messages
  • Arizona, United States
I agree with Mr fix it but l would pull spark plugs out and take radiator cap off and pressure test system to see if it holds pressure another way to test is remove valve cover pull rocker arms so all valves are closed then pump 120 pounds of shop air into cylinders one at a time and look for bubbles in radiator
  • Posted 23 May 2021 09:16
  • By Scott_
  • joined 16 May'21 - 309 messages
  • Pennsylvania, United States
Scott
Even if the oil looks good a bad head gasket will do that. I would look closely at the spark plugs and compare them to each other and do a compression test.
  • Posted 18 May 2019 19:27
  • By mrfixit
  • joined 11 Dec'08 - 1,434 messages
  • New York, United States

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