JLG G6-42P Service Manual - Manual (Page 132)

OPERATING IN WARM TEMPERATURE CLIMATES
John Deere engines are designed to operate using
glycol base engine coolants.
Always use a recommended glycol base engine
coolant, even when operating in geographical areas
where freeze protection is not required.
IMPORTANT: Water may be used as coolant in emergency
situations only.
Foaming, hot surface aluminum and iron
corrosion, scaling and cavitation will occur
when water is used as the coolant, even when
coolant conditioners are added.
Drain cooling system and refill with recom
mended glycol base engine coolant as soon
as possible.
pg.5