do i need to drain all the fluids before doing head gasket work?

You`ll nned to drain coolant and in the doing of headgasket you`ll need to do a oil and filter change ,,,,,,,,,,,,,,,be sure it s a headgasket before jumping into deep water .....
bubbles in recovery jug while running .....heatr not working...
can pull plugs and pressure test cooling sytem overnite and in a.m. crank engine over while watching cylinders and see it any push coolant out whilee being cranked

bg
June 2006

What makes you think that it is a head gasket with no coolant in the oil or vice versa? Try taking the oil filler cap off to see if the rocker box is presurising. Do the same for the water - NOT when hot. We had a Merc once that was always losing water. After some years it turned out to be a pinhole radiator leak.

As you your question. I've not heard of peope doing a head gasket without draining the engine's fluids.

Terry
June 2006