How to Avoid Liner Pitting
Older engines may be vulnerable
Does your diesel engine have a replaceable cast iron cylinder liner? If so, it may be
vulnerable to accelerated corrosion as a result of liner pitting. Supplemental Coolant
Additives (SCAs) are effective to prevent liner pitting when used in the cooling system
according to recommended concentrations. SCAs form a protective film on the
coolant side of the cylinder liner, allowing a layer of protection against damage from
the implosion of air bubbles caused by high frequency vibrations created during the
normal operation of a running engine.
SCA Protects Liners from Pitting
The Supplemental Coolant Additive forms a protective film on the coolant side of
the liner and transforms soft ferric oxide or rust into extremely hard FE3O4 and.
Fleetguard’s DCA4 SCA provides optimal liner pitting protection and contains nitrite
and molybdate. This protective layer makes it virtually impossible for pitting to occur.
Follow a few simple rules to avoid problems
- Check the SCA level each time you change the oil.
Liners are protected from pitting by elements in the SCA. Liner pitting can develop
within 500 hours of operation under severe conditions when plain water is used as
- Be careful to avoid topping off radiators higher than the fill neck.
When you top off fluids, the expansion area in the top tank is eliminated. Coolant
is then forced out of the system when the engine warms up, and the SCA level is
- When you add make-up water, always add SCA.
Maintain the SCA levels to protect cylinders from liner pitting.
- Correct proportions are assured when you use a coolant premixed with SCA.
The ratio of coolant to SCA can vary with cooling system capacity, and it is the
same for both the initial fill and topping off. To ensure that proportions are always
correct, use a coolant premixed with SCA.
- If you need to add large amounts of water to increase fluid levels, chances are that
SCA was not added every time water was, unless you’re using a premixed coolant
that contains SCA.
- If there’s no coating on the liners, it’s a sign of low SCA levels.
- If your oil analysis records show traces of potassium, it’s possible that coolant has
leaked into the oil, and oil has leaked into the coolant already.
For more information, contact the
location nearest you today!