Boom lock cylinder seal 334/C9418 JCB, aftermarket

Boom lock cylinder seal 334/C9418 is an aftermarket part for the JCB machines. This seal is used in the boom lock cylinder.

An oil seal seals a rotating shaft where it leaves its housing, keeping oil in and dust and water out. A metal or rubber-covered outer case holds the seal in its bore, while a spring-loaded rubber lip bears on the shaft. When the lip hardens, wears or its spring weakens, the seal starts leaking: the oil level drops and dirt getting in ruins the bearings.

Specifications

Compatibility

According to sources, 334/C9418 is a type 839 lip seal measuring 20 x 26 x 4 mm. According to the product card, it is used in the boom lock cylinder. Other parts are in Seals and oil seals.

Fitting

Remove the old seal without scoring the bore or shaft. Clean the bore, lubricate the seal lip with the working oil or grease and drive the seal in evenly, lip towards the oil, with a flat mandrel on its outside diameter. After assembly, top up the oil and check for leaks after the first run. Where possible, the new seal is set a few millimetres away from the old seal's track rather than on it.