Leaking from head bolts
It has been established there are some dry and wet head bolts. Most are recommending thread tape on the wet holes.
For years, I have had very good success with Harvey Seal. Harvey™ HarveySeal is a multi-purpose, yellow thread compound that is non-hardening and non-separating. It works with everything from plain water, antifreeze, gas, oil, etc. but is very difficult to wash from your hands. Is the goto in my box when I need it to seal and stay sealed the first time.
Brand: Harvey
Set Speed: Immediate
Product Type: Soft Set
Set Type: Soft Set
Material Compatibility: ABS
Material Compatibility: Aluminum
Material Compatibility: Brass
Material Compatibility: CPVC
Material Compatibility: Copper
Material Compatibility: Plastics
Material Compatibility: PVC
Material Compatibility: Stainless Steel
Material Compatibility: Cast Iron
Withstands up to 3,000 psi on gases from -50° to +400°F and 6,000 psi on liquids from -50° to +400°F