primary chain hydraulic tensioner

Hello ,

I need some help to understand the hydraulic chain tensioner way of working ..
From where arrived the oil inside the cover ?
How the oil pressure in the tensioner is made ?
I am reassembling this part but I can't understand how tensioner can be under pressure

Oil from the primary chain drips into he reservoir created by the flat plate on the outside of the tensioner. When the spring-loaded tensioner shafts extend, the ball check valve in the bottom of the res opens and draws in oil. When the tensioner shafts are compressed, the ball check closes and creates pressure behind the slider shafts and holds the chain in tension. Any oil that escapes around the perimeter of the shafts is replaced from more drippage into the res. The springs inside the tensioner shafts assure that the tensioner is always being pushed outward towards contact with the chain and the shafts stay relatively full of oil. There is no pressure from the pump or oiling system.

I always prime mine by filling the res with a squirt of oil and working the arms in and out before I button up the cover, this prevents any initial rattle upon startup.

Manursr said:

I need some help to understand the hydraulic chain tensioner way of working ..
From where arrived the oil inside the cover ?

Click to expand...

The tensioner is not connected to the engine's lubrication system or oil pump.

The tensioner is fed by primary case oil dripping from the upper run of the primary chain into the tensioner reservoir.

Manursr said:

How the oil pressure in the tensioner is made ?
I am reassembling this part but I can't understand how tensioner can be under pressure

Click to expand...

It doesn't actually make pressure.
Imagine an oil filled tube or gallery with a piston at each end. If one piston is pushed inwards the other piston will be forced outwards by the oil between them, and that's basically how the tensioner plungers operate.

thanks guy !

FWIW
There is a gasket that goes under the tensioner cover. It doesn't show up on all parts diagrams.
Pete