cooling system TMD40A



I have a problem with the heat exchangers on my vovo TMD40A's. Occasionally the coolant is forced out of the heat exchanger, usually through the cap on top of the exchanger. I have stripped the worst offender down, and checked the thermostats etc. and the only percievable problem appeared to be heavy discoloration of the coolant. ANy ideas as to what may have been vcausing the problem??


New member
16 May 2001
Bungay, Suffolk
I have had a similar proble, caused, I think, by the coolant overheating and 'boiling' off throught the header tank cap. The cure in my case was to flush the coolant and use a two part Holts descaler then top up with new antifreeze/water at a ratio of 40/60. The cooling system on these engines is a bit temperimental and must be in pristine condition to work properly. It is usually suggested that you check the system throughout, both the raw and fresh water sides as any slight fault can give trouble. It may also be worth checking the annodes in the oil cookler and heat exchanger, if they are more than half used they should be changed, and it can happen quite quickly. Sometimes the annode can get partly used and break off of the holder causing a restriction or partial blockage in the system. For more information and a very informative opinion on any engine related issues go to and post a question there.
Good luck,

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