Does anyone know the size of the o-rings used on the cover?
Diameter and thickness.

thanks

 

I received a genuine Volvo replacement servo cover today and the O rings have a 2.4mm crossection and look to have 47mm ID.
I previously bought an aftermarket servo cover which started to leak about 2 months after installation.
At the time I installed it I questioned whether the O-rings would leak. The original 2001 cover, which never leaked, fit more snug.
The only reason I replaced it was due to a high rate of failure with the original design. Should have let it be. Lol

 

Today I replaced the aftermarket servo cover with the factory part.

The O-rings on the aftermarket part made by "Precision Parts Sweden" were indeed a different size than came with the factory part.

Cross section of factory orings is 2.4mm
Aftermarket ring CS is 2.0mm.
Both covers come with 3 O-rings. Two for the cover and one for the piston inside.
I'm sure the thinner ring on the piston may also be a problem as it may not maintain the necessary pressure.
Anyway all is fine now.
No more hemmoraging of transmission fluid out the cover and no more shift flare from 2nd to 3rd.