Volvo Maintenance Hints for 7xx/9xx - Bill Garland's Nuclear ...

Pan Gasket Gasket Kit
It's a good idea to have a plate to hold the accumulator pistons in place in the
transmission as you take the valve body out. I've heard of people getting by without
one but I felt it was better not to risk having the pistons drop out onto the floor. I made
one from a scrap piece of 1mm thick steel plate. Three holes are drilled in the plate
corresponding to the pan bolt holes and it is held in place using the pan bolts. See pic
below. The arrow points to the correct holes. I had to redrill them because I was
slightly off with my measurements, so ignore the bottom holes.
Accumulator
piston
holding tool
If you are planning to do a full valve body service, allow a whole weekend. This is
NOT a job you will do in an afternoon so plan it for a time when you won't need the car
for a couple of days. It is possible to replace just the check ball and put everything
back together in a day but while you're in there you might as well do a thorough job.