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 - 318 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

Post your Reply

Forkliftaction accepts no responsibility for forum content and requires forum participants to adhere to our rules of conduct. Click here for more information.

If you are having trouble using the Discussion Forums, please contact us for help.

Global Industry News
edition #1261 - 18 December 2025
In this week’s Forkliftaction News , we report on an activist investment firm increasing its stake in Toyota Industries Corp (TICO), in a bid to stop the privatisation of the materials handling equipment manufacturer... Continue reading
Movers & Shakers
James Brown James Brown
Chief operating officer, Bulldog Battery Corporation
Commercial excellence roll-out manager, TVH Parts
President EPG Americas, Ehrhardt Partner Group (EPG)
CEO, Duravant
Upcoming industry events …
March 3-7, 2026 - Las Vegas, NV, United States
January 28-30, 2026 - Bangkok, Thailand
31 March 2026 - Dubai, United Arab Emirates
Editorial calendar - planned features
CONSTRUCTION FORKLIFTS
HANDLING GOODS IN THE COLD
LOADING/UNLOADING FREIGHT
BROWNFIELD AUTOMATION
FORKLIFT ATTACHMENTS
BATTERY AFFORDABILITY AND LIFETIME
FORKLIFT SAFETY

PREMIUM business

Libiao Robotics
Creating robotic warehouse solutions that automate and elevate your business.
Latest job alerts …
Bensenville, United States
Monmouth, IL, United States
Bensenville, United States