When servicing, a visual examination is almost always carried out. Thereby, it's wise to expect the possibility of existing malfunctions. In any event, if the system is losing coolant, first of all, one always runs the engine to warm it up. A device, that puts a certain amount of pressure (and not too much!) on the system, is an advantage. Radiator, flexible tubing and waterpump are to be observed. Certain additives in the coolant sometimes also help by e.g., causing it to give off a flourescent glow under a certain light. If no leakage is noticeable from the outside, the suspicion falls on the engine itself. In this case, a compression test and a pressure loss check, done successively, are necessary.
How it works
The normal servicing deals, first of all, with the belt drive. If the adjustment is too slack, the waterpump can only transport too little or maybe even nothing at all. Also the fan-belt or flat-belt should not be frayed. The belt tension should however, also not be too taut. In certain systems, a too taut setting is almost impossible anyway, through a given spring pre-tensioning.
In summer the mixture proportions are also to be observed, because it is not certain that a check will be done again before winter. The above figure shows an areometer with which coolant can be suctioned up and be checked. Due to the fact that the density of water and additive differ, the anti-frost temperature can be read on the float. There are also devices with a pendulum float. In the case of the refractometer, some coolant must be applied onto a measuring prism. In addition to the security of not freezing, the replacement deadlines of the individual manufacturers are to be observed. It is especially important to know, that there are different liquids which one may not mix with each other, Ethylenglykol and Propylenglykol. 09/09