Valve stem seal 320/03533 JCB Dieselmax, aftermarket

Valve stem seal 320/03533 is an aftermarket part for the JCB Dieselmax 444 engine.

The valve stem seal fits on the top of the valve guide and stops oil from the rocker area running down the stem into the combustion chamber. A hardened or worn seal causes blue smoke, especially at cold start and after long idling, and higher oil consumption. The photos show a seal with a spring-loaded lip and metal body. The seal lets just enough oil past to lubricate the stem in the guide and holds back the excess. Seals on the exhaust side run hotter and harden sooner. The seal rubber is an oil- and heat-resistant compound, which keeps it flexible for longer.

Specifications

Compatibility

The part is listed for JCB 3CX and 4CX backhoe loaders. A four-cylinder engine with four valves per cylinder takes sixteen seals. The catalogue also has the genuine version of this part. Other parts are in JCB Dieselmax engine.

Fitting

Lightly oil the seal lip before fitting. After assembly, watch the exhaust for smoke on first start. Check the valve clearances when the seals are replaced. Remove the old seals with pliers or a puller without damaging the guide.