|
|
When is a cooling system not a cooling system? When it's not clean or when it is plugged and contamination bypasses the filtration system! So much has been written about cooling systems and cooling system maintenance it would seem as though nothing new could be added; not so. Everything that has been written on the subject assumes that the cooling system is clean when reformulation or recycling of coolant begins. Some reports have suggested that as many as 80 percent of heavy-duty diesel cooling systems are contaminated with a variety of corrosive and/or chemically active compounds. A cooling system operates by directing coolant flow through the engine and other components to absorb heat, and then directing the coolant into the radiator to cool down. The flow of the coolant starts at the water pump and follows a course through the engine and other components. The process and routing goes on through the engine block, heater, cylinder head, the radiator and finally ends the cycle when it reaches the water pump where it starts the process again. The idea is to circulate a fluid, antifreeze and water, that thermally and chemically matches the cooling demands of the engine - and to keep the system as clean as possible during the process. Without the careful selection and maintenance of coolant, you can expect problems in the cooling system. Acceptable coolants are formulated to minimize the possibility of a number of problems:
These problems can be avoided by using correct additives, a good water source and by sufficient filtration of the liquid. Before any program is initiated, however, the cooling system must be clean. How do you know if a cooling system should be cleaned? Here are some indicators:
A common occurrence Contrary to common belief, these situations are not occasional occurrences; heavy-duty cooling systems are subjected to such risks daily. Therefore, cleaning should be a routine procedure scheduled at least once a year. A high quality cleaner will offer the same protection to the cooling system as a good inhibitor. The most obvious coolant-related failure is overheating. Poorly circulated coolant, dirty or contaminated coolant or a plugged filtration system are major contributors to overheating. Other factors may include a loss of coolant, a plugged radiator core, broken or leaking coolant hoses, excessive engine load, and failure of the water pump or water temperature regulator, just to name a few. Use additives properly Proper maintenance of all cooling system components is imperative if you hope to avoid problems. Supplemental coolant additives (SCAs) also offer protection. Additives can protect the system from deposits, corrosion and liner pitting, but starting with a clean system is paramount. Mineral scale and corrosive products tend to build up on heat transfer surfaces. The build-up of such deposits results in hot spots that can crack heads, accelerate ring wear, scuff cylinder liners, score pistons and burn valves. All cooling system components need protection from corrosion. Additives protect the various metals that the coolant contacts - cast iron, steel, aluminum, copper, brass and solder alloys. Charged coolant filters are the most effective means of maintaining diesel engine cooling systems. They offer two benefits: the most effective way of controlling the addition of SCAs and the efficiencies of mechanical filtration. Most cooling system problems are due to over-concentration or under-concentration of supplemental coolant additives and /or antifreeze, as well as contamination of coolants with debris. A balance is needed Over-concentration causes a high level of solids in the cooling system, which can cause water pump seal leaks, corrosion, solder bloom, plugging of coolant passages, silicate gel and deposits on heat transfer surfaces. Over-concentration is generally due to incorrect test methods, use of pre-charge filters instead of service filters, addition of additives when not required and addition of liquid additives when pre-charge and service filters are used. This condition may require cleaning.
Debris within the cooling system also contributes to many cooling system problems: wear of water pump seals and liner crevice seals, sticking thermostats and plugged coolant passages. On-board coolant filtration is fairly effective in removing debris. The addition of a pre-charge dose of SCA and a smaller, maintenance dose of SCA at each oil change interval gives an acceptable, nearly constant level of protection against liner pitting. Total dissolved solids (TDS) can continue to increase as SCA is periodically added, but proper make up liquid can counter this tendency. A portion may become insoluble and removed by the filter, but most will remain in solution. Here are some tips for good cooling system maintenance:
Simple, inexpensive test kits are readily available and can accurately measure the concentration of supplemental coolant additive and the ethylene or propylene glycol in the coolant mixture. Coolant testing can be done quickly and easily and helps protect against insufficient or excessive concentrations of chemicals that can have serious consequences. Diesel operating temperatures have been increased in the newer model engines to improve efficiency. Protecting the cooling system is now more important than ever. Proper coolant selection and system maintenance will help the engine reach its maximum service life - only if the program starts with a clean engine!
|
On the other hand, under-concentration of SCA or antifreeze can result in pitting and inadequate freeze protection. It also allows rust and scale deposits to form on heat transfer surfaces and causes general corrosion of the cooling system. Incorrect test methods, not adding additives when necessary, failure to pre-charge at the initial fill or during coolant replacement and topping off with coolant without SCA all can cause under-concentration. This condition requires cleaning.|
Copyright © 2007 Enviro-Cool, Inc. All Rights Reserved |