Zetor 3320 Operator's Manual Supplement page 64

PLANNED TECHNICAL MAINTENANCE - USED LIQUIDS AND FILLS
Antifreeze for cooling system and heating Z 3320 - Z 7340 (tab. 8)
Antifreeze FRIDEX-STABIL or FRTIDIOL 91 and demineralized water in
ratio 1:1,5 (add the mixture in this ratio).
Antifreeze for exchanging abroad must contain anticorrosion additives
protecting all materials of cooling system and tractor heating (including
rubber parts and cylinder head gasket).
Note:
1. Antifreeze FRIDEX-STABIL and FRDIOL 91 are mutually mixable.
2. Above mentioned liquids must not be mixed with liquids of another
marks.
3. Exchange the liquid after two years.
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