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Cooling fluid reservoir cap: replacement and selection

When and why it is necessary to replace cooling fluid reservoir cap

Manufacturers do not specify exact operational lifetime for the cooling fluid reservoir cap. Replacement of the part is performed at appearance of cracks on it or at breakage. Moreover, a new cap is installed at valve jamming.

Mechanical damages of the component appear as a result of a road accident. The cause of valve jamming lies in its clogging. Particularly, this is possible, at appearance of emulsion in cooling fluid due to ingress of oil.

Presence of cap defect is indicated by leakage of working fluid from the reservoir, which is noticeable because of specific smell in the passenger compartment. Also leakages under the radiator or smoke from under the bonnet can appear.

During replacement of the cooling fluid reservoir cap you need to take into account, that it can be opened only at turned off and cooled engine. Cooling fluid circulates under the pressure and have high temperature, that is why there is a risk to sustain a burn wound if safety precautions are not observed. It is worth remembering that untimely replacement of the part can lead to improper functioning of the cooling system, which is fraught with engine breakdown.

How to select cooling fluid reservoir cap

The items differ from one another by construction. Thus, there are caps with two valves: safety (releases high pressure) and vacuum (normalizes low pressure). Also there are parts with one valve, which performs both functions noted above.

High-quality expansion tank caps are presented in the assortment of many brands. The most famous are Metzger, AKS DASIS, Swag, Gates, Topran, Vaico.

The items diverge from one another by shape, valve diameter, height and thread size. Moreover, maximum allowed pressure is noted for the components and it depends on the type of the radiator installed.