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Tips on fitting water pump gland packing

The water pump contains two sealing glands which are rings of special sealing material each of which is sandwiched between a pair of angled faces. These act to compress the sealing material on to the shaft to make an effective seal. On the majority of cars manufactured after 1930 the gland rings are separated by a spring-loaded telescopic 'lantern ring'. On earlier cars the lantern ring was a solid, one-piece item.

The gland packing that we offer is supplied in one straight length which needs to be cut in two to produce the two sealing glands. To form the gland ring the material should be wrapped tight around the pump spindle such that the free ends lie side by side. Using a sharp blade the free ends are cut off at an angle, such that the two cut ends overlap. When fitted, the angled faces will overlap and lie one on the other, making a scarf joint.

When assembling the pump, the first gland ring should be fitted followed by the lantern ring arrangement, followed by the second gland ring.

Note that in the case of the spring-loaded lantern ring it is important to fit the outer part into the pump body first. If this is reversed it will inhibit the flow of grease.

The knurled nut on the forward end of the pump body should never be more than hand tight. If over-tightened too much pressure may be put on the gland packings. The friction generated will cause the grease within the shaft to liquefy and may cause the shaft to overheat. We have seen them blue with heat!