Inliners International Forums General Discussion AMC/JEEP jeep 258 pressurizing

Hi guys,, not much luck in cooling problems lately,,,I am wrenching on a friends jeep they could not get to cool,it got VERY hot many times,,new rad, new water pump, stat tested ok, across reading the manual, I notice there is a serpentine water pump (reverse rotation)option in 1985,,back to store to find they had a wrong pump,, got the one for v-belt and back installed,,,now when the engine is cold it pumps the rad full of air, enough to blow up the upper rad like a balloon,,, if you keep purging the air, after the engine gets to temp, the pressure stops rising and the engine runs great,,,looking for a cracked head gasket,I turned each cylinder to top dead, and filled cylinder 100psi,,none of the cylinders raise or bubble through the rad,,???, Is there any other way to get exhaust in a water jacket,,any other ideas,,?? oil is clean,, and no water from exhaust pipe, engine seems right??

Walt,, can I slowly start to turn the engine over to crack the exhaust valve, then plug the exhaust,,? will that force the air into the water jacket,

You might pressurize with the piston at BDC. I have seen many engines with a crack half way down the cylinder wall..