Gear Oil or Brake Fluid?

[DartGTDan]

My buddy has a '65 A100 pick up truck. He's found a liquid on the passenger rear wheel after sitting all winter. He's not sure if it's brake fluid leaking from the wheel cylinder or if it's gear oil leaking from the axle seal.

How do we tell which liquid it is? I'm thinking if it was brake fluid the paint, on the painted steel wheel, would have been damaged (after sitting for 5 months). He simply wiped it away with no visible paint damage.

I thought maybe try smelling the liquid. Gear lube is pretty pungent vs. brake fluid.

Any ideas, suggestions?

 

[pete9857]

Why not take off the brake drum and inspect it. Got to come apart anyway to fix.

 

[ir3333]

clean up with water and it's brake fluid.

 

[A38Valiant]

Gear lube feels slimy, brake fluid feels almost gritty when you rub it between thumb and finger. Not actually gritty, not really tacky, can't describe it but it has "bite", while gear lube is just slimy.

 

[6pk2goDemon]

Gear oil has a distinct smell all its own. The nose will know.....

 

[No name needed]

Dog pee.

 

[DartGTDan]

I agree the nose will know.
He doesn't have time to do much of anything. It would be a major undertaking to pull the wheel and brake drum!!!
Will pass along the info