Hydraulic tappets — removal and installation

A few words should be said about hydraulic tappets, as improper handling can damage the engine. Sometimes you can still hear noises from the valve cover area, which, however, do not mean that there is some kind of malfunction. Noises can appear, for example, when starting the engine for the first time after a long period of inactivity, which led to the outflow of oil from the hydraulic tappets and the formation of a gap in the valve drive. After a short time, the noise will disappear again. If the pushers continue to make noise after a certain time, then you need to check their condition in accordance with the instructions below.

When removing pushers, the following instructions must be observed:

• immediately after removal, mark the pushers. It is best to mark them with the help of marks applied on the inside. To do this, draw one line on the first pusher, two lines on the second pusher, etc. On fig. 412 shows how the pushers should look after marking them;
• after removing the hydraulic tappets, do not install them with the contact surface down;
• replace the pusher completely, as it cannot be adjusted or repaired.

If the noise of the valves seems too loud to you, then the pushers can be checked as follows:

• start the engine and let it run until the fan turns on;
• increase the engine speed to 2500 min^–1 and let it run for about 2 minutes;
• if the tappets are still noisy, then the faulty tappet can be identified by removing the cylinder head cover, as described when disassembling the engine, and rotating the camshaft so that the camshaft cam for the tappet being checked is facing up;

• push the pusher down with a piece of plastic or wood (pic. 413). If the gap is more than 0.1 mm before the valve opens, then this pushrod must be replaced.

Attention! After installing a new tappet, do not start the engine after assembly for about 30 minutes, otherwise the engine may be seriously damaged.