[glennpm]

AI input:

"For a 1935 Ford Flathead V8, a reverse flush is generally not recommended and many experts advise against it due to the risk of dislodging debris into narrow passages or damaging older components. Instead, the consensus among classic Ford owners is to use chemical rust cleaners like Evaporust or Envirorust to dissolve internal rust without aggressive pressure, followed by multiple flushes with white vinegar or distilled water.

Key considerations for your 1935 model include:

Avoid High Pressure: Standard reverse flushing uses city water pressure (40–60 psi), which is far higher than the cooling system's design limits and can blow out freeze plugs or damage the radiator.

Rust Removal: If the engine has significant internal rust, soak the block and heads with a rust dissolver (like Evaporust) for several days before flushing, rather than trying to force it out with high-pressure water.

Coolant Choice: Avoid Evans Waterfree Coolant for this engine; it is expensive, causes leaks in older engines with tiny cracks, and operates at higher temperatures that can be detrimental to a Flathead V8. Use a standard glycol-based antifreeze with a quality anti-corrosion additive.

Procedure: The safest DIY method involves draining the old coolant, filling the system with white vinegar (to dissolve rust/minerals), letting it sit, draining, and then flushing thoroughly with distilled water until clear before refilling with a proper 50/50 antifreeze/water mix."