Model A question

[Dave Loving]

I have a '31 A400 that gets little use because it's not a "T".
I recently Trailered it up to Maine, (4hr. Ride) After I off loaded it I checked all the precious bodily fluids and found the coolant was down 2 gallons.
(it was full when I put it in the Trailer)
I refilled it and drove it for 4 days, never lost a drop.
When I got home I checked the radiator and it was down 2 gallons, all over the floor of the trailer.
Once again I refilled it, drove it, and it hasn't lost any in more than a week.
There is no coolant in the crankcase, I can not find a source of the leak.
Any Ideas? I'm asking you guys 'cuz I don't belong to any A clubs.
Thanks,
Dave

[ThreePedalTapDancer]

Radiator, hoses, cracked block are a good place to look.

[TWrenn]

The drain petcock on the A is hard to see, yet alone "work", being tucked up under the inlet pipe where its attached to the bottom of the radiator. . Since you had fluid all over the floor but it stayed OK while driving, my guess is it's the drain cock. Look for fluid running down those wonderful engine pans for tell-tale signs. While driving, the circulation may help prevent it from dripping nearly as much as it would while sitting still.

[TWrenn]

Forgot to add, it's possible now that gunk has the petcock now plugged, hence no fluid on the floor.

[TXGOAT2]

Petcock, lower hose connections, pinhole in lower coolant pipe, transient leak in lower radiator tank. (?) The A system is pretty much the same as a Model T except for the water pump. 2 gallons missing amounts to most of the total capacity, so I'd look for a leak down low in the system. With the car not running, the high mounted water pump probably could not leak 2 gallons. I doubt that even a large head gasket leak could dump 2 gallons, for the same reason, but a leak low on the radiator or in the lower coolant pipe, hoses, or petcock could.

[kmatt2]

The two gallons of coolant lost in trailering, twice, going and returning home is a lot of coolant loss to not have any coolant loss while driving the Model A. Does it leak any coolant on the garage floor when left sitting parked for a week or so ? If no leaking parked check the lower hose for any leaking, even a few drops, by moving the lower hose and coolant pipe around by hand. It is possible that the way the car was tied down on the trailer was moving the lower hose or coolant pipe around on bumps going down the road.