ENGINE - Continued
3-8.11 Cylinder Block - Continued
Cylinder Block Pressure Test In Truck
This procedure is to be used as a quick test to determine if the cylinder heads or cylinder block has been
(1) Remove rocker covers, para. 2-19.3, and oil pan, para. 2-19.11.
(2) Check/fill water jacket with mixture of water and antifreeze, (item 2, Appendix B), containing at least one
gallon of antifreeze. The antifreeze will penetrate small cracks and its color can be used in detecting leak
(3) Apply 14 psi (100 kPa) via radiator fill neck. Maintain pressure for two hours if required, to allow mixture time
to work its way through any cracks that may be present.
(4) Examine exterior of block, interior cylinder bores, air box, oil passages and crankcase area for presence of
coolant mixture and repair/replace components as required.
Block End Plates Inspection
(1) Remove gaskets from both front and rear end plates.
(2) Inspect front and rear end plates for nicks or scratches. Check plates for warpage. Replace plates if warped
or scored too deep to seal with new gasket.
(3) Inspect plug nuts for cracks or damaged threads. Replace plug nuts, or end plate as required.
(4) When installing new plug nuts, support end plate on a solid flat surface to avoid destroying the plate. Press
nut in end plate until head on the nut seats on end plate.
(5) Thoroughly clean gasket material from block ends.
Main Bearing Journal Bore Inspection
(1) Check the bore diameters original position. No. 1 or front main bearing cap is also stamped on the face of
the pan mounting flange of the cylinder block.
(2) Lubricate main bearing bolt threads and bolt head contact areas with a small quantity of anitseize compound
(item 4, Appendix B). Tighten to 240 ft lb (325 Nm) when making this check, do not install main bearing
(3) Specified bore diameter is 4.813 - 4.812 in. (122.22 - 122.25 mm). If all four bores do not fall within these
limits, the cylinder block must be repaired or replaced. For repair, refer to REPAIR following.