Usage of upper O-ring of chain tensioner

[HKZ Bob]

Hi
I have two tensioners disassembled where the O-ring no 9 was missing.
Outer diameter 13mm inner 8mm

Where does it this no 9 o-ring belongs to and what is the purpose.
I assume on the piston 7 upper groove but I want to be sure.

Please add photo, would be great thank you.



Thank you
bob

[ajwans]

IIRC it is inside part #7. There should be a groove inside for this o-ring.

It was really hard to get out until I discovered the perfect tool for picking
it out - a corkscrew.

andy

[HKZ Bob]

Originally Posted by ajwans

IIRC it is inside part #7. There should be a groove inside for this o-ring.

It was really hard to get out until I discovered the perfect tool for picking
it out - a corkscrew.

andy

Hi
What is this o-ring 9 good for?

BR
Bob

[ajwans]

I guess it stops oil from escaping up the stem. Part
7 seals at both its inner and outer surface for some
good reason.

andy

[john walker's workshop]

the o-ringed disc keeps air out of the lower section. air entry is what causes tensioner collapse. air compresses, liquids don't, remember?

[HKZ Bob]

Originally Posted by ajwans

I guess it stops oil from escaping up the stem. Part
7 seals at both its inner and outer surface for some
good reason.

andy

Part no 7 has two o-ring grooves
The big o-ring 8 seals against the liner 19. but the small oring 8x13x2.5 Viton is been inserted on the upper grrove on part 7.

But what it is purpose?
Is is for centering the the disk 5?

BR
bob