ROPA Tiger 6, Original Operating Manual, Page: 385 / 564

Maintenance and Service
Diesel engine
385 / 564
7.1.4.4 Remarks of ROPA on the coolant (general information)
Normally, coolant consists of water and corrosion protection/antifreeze agent. The cor-
rosion protection/antifreeze agents (ethylene glycol with corrosion inhibitors) have the
following tasks in the cooling system:
Sufficient corrosion and cavitation protection for all components of the cooling sys-
tem.
Lowering of the freezing point (frost protection).
Raising of the boiling point.
For reasons of corrosion protection, about 50 vol.-% corrosion protection/antifreeze
agents must be added to the cooling liquid, if the expected environmental tempera-
tures do not require even higher concentration. This concentration (50 vol.-%) offers
antifreeze protection up to about -37°C. A higher concentration is only sensible for
even lower environmental temperatures. Even in case of extremely low environmen-
tal temperatures, do not use more than 55 vol.-% of corrosion protection/antifreeze
agents, since the maximum frost protection is achieved then, and greater share in the
mixture reduces frost protection and worsens heat dissipation (55 vol.-% corresponds
to frost protection up to about -45°C). If these coolant regulations are not complied
with, then corrosion and damage to the cooling system are inevitable. Adding of cor-
rosion protection/antifreeze agents raises the boiling point. Increased pressure further
increases the boiling temperature. Both physics coherences are used in modern cool-
ing systems – the maximum coolant temperature is increased without increasing the
hazard of boiling. Corresponding to the higher temperature level, the cooling perfor-
mance increases.
7.1.5 Valve clearance adjustment
Checking respectively adjusting of valve-clearance is required after the
first 1000 operating hours and then once annually respectively every
2000 operating hours. This work may only be performed by people expressly autho-
rised for this work by Volvo.
Valve clearance for cold engine:
0.30mm +/- 0.05mm Inlet valves
0.60mm +/- 0.05mm Outlet valves
3.70 - 4.00 mm VCB (engine brake)
(see Volvo workshop manual)
Valve drive with VCB (Volvo Compression Brake)