Volvo 850 Accessories Manual page 17

Fig. 14: Removing Oil Pump Retaining Bolts
Courtesy of Volvo Cars of North America.
OVERHAUL
CYLINDER HEAD
Cylinder Head
Ensure all mating surfaces are clean. Measure cylinder head
warpage. If longitudinal warpage is less than .020" (.50 mm), or
lateral warpage is less than .008" (.20 mm), resurfacing is not
required. If warpage is greater than specifications, resurface
cylinder head. Maximum resurface limit is .011" (.30 mm).
Valve Springs
Measure valve spring free length. Replace any spring shorter
than minimum free length specification. See VALVE SPRING FREE LENGTH
in VALVES & VALVE SPRINGS table under ENGINE SPECIFICATIONS.
Valve Stem Oil Seals
Place new seal on valve stem. Remove protective sleeve. Using
Drift (5379), push seal onto stem by hand only as far as possible. Do
not use a hammer to install valve stem seals.
Valve Guides
Three replacement valve guides are available. Standard valve
guide has no grooves at top and is .472" (12 mm) in diameter. First
oversize valve guide has one groove at top and is .476" (12.1 mm) in
diameter. Second oversize valve guide has 2 grooves at top and is .
480" (12.2 mm) in diameter.