chain tensioners
 

Can someone please explain to me how the hydraulic chain tensioners work? I see that they have two chambers, the first has the piston and spring. What is the other chamber for? Is it a check valve or something? Does it come apart and how? What is the proceedure for bleeding these things to be sure you have all the air out of it? How do they bleed down in operation? Is there an oriface that lets the oil out on compression?

Lots of info here:
http://www.pelicanparts.com/techarticles/911_carrera_chain_tensioners/911_carrera_chain_tensioners2.htm

Sand Man - I have already read that article and many others. If you read my post, none of the information I need is covered in the readily available information or shop manuals.

all apologies for trying to help...

I don't believe there is any bleeding involved. When I installed mine I just hooked 'em up and started the engine. No problems encountered. I guess the seals will let air pass by, or oil just pushes on air, air pushes on mechanism. However it works didn't worry me, just that they work!

I don't know how they work exactly but i can give you observations. When slowly compressing the tensioners in a vice to put the pin in the locking hole and store them, i noticed that oil bleeds out from a hole near the top of the contact. I also notice that if you release it slightly the oil will stay put, not reverse inward. Could there possibly a check valve in there that only allows the oil to flow in one direction i don't know. But then if you start to recompress the tensioner oil continues coming out, not air. So if i had to guess, i'd say that oil pressure builds and steadily exits out of that hole near the top. Maybe it's there to make the pressure exhibited by the tensioner more uniform over a range of oil pressures, i don't know.

Aren't you supposed to soak them in oil b/f you install them?

Aren't you supposed to soak them in oil b/f you install them?

Yes, but i was removing them.