COOLANT SEEPAGE ON CHEVROLET 6 CYLINDER ENGINES Back
When rebuilding one of the above mentioned Chevrolet engines, it is recommended that they be pressure tested and checked for cracks.

It has been found in some instances, that a crack will develop from an oil line into the lifter bores, intersecting the water jackets.

 It is recommended that these engines be pressure tested to check for cracks rather than the magnetic type crack finder, as many times these cracks are inaccessible, and a magnetic type crack finder would not show them up. And, as many times these cracks are located in an inaccessible area, the blocks have to be discarded.

In making this pressure check the rebuilder is avoiding the possibility of a premature engine failure, due to coolant seepage into the crankcase.

 

(P51)