Hi guys and gals,

I swear I typed this a few minutes ago...but it is not posted (that I can find)....Hmm.....

I have been out driving my truck today. Its running well and I had a blast. Lots of smiles and waves!

I am going to flush the cooling system before I take off to Branson, MO next Saturday and I have a few questions.

1. What pressure is the radiator cap supposed to be?

2. What thermostat is supposed to be in it (272 Y-block V8)?

3. How much fluid does the whole system hold? (will flush and drain the block too-if I can)

4. Does the antifreeze get mixed 50/50 in these just like the newer vehicles?

I have a shut off valve to go in the heater hose. It is warm enough without heat from the engine blowing in.

 

Brian, I'm running a 3-4 lbs cap, on my y-block. Too much can cause old radiators to split, and it runs fine with the lower cap(supernats and back)

If you pull thermostat, just put a hose in the intake, and remove the lower hose. Also, be sure the overflow "purge" line coming off of the radiator neck is not clogged. I think it takes about two gallons. 50/50 is fine. Check those heater hoses and make sure the thermostat doesn't slip out of the neck before you tighten or you'll lose an ear. I sealed both sides of the gasket with some permatex aviation, and its bone dry. Have fun,

 

Thanks for the information. I plan on driving to town early in the morning and get parts.

The afternoon is for working on the truck again.

Any clue what the thermostat temperature is supposed to be?

 

1948/56 Ford truck parts catalog sez: 160 degree.

1954/56 F100/350 ~ 239/256/272: A8AZ-8575-D (Motorcraft RT-16) Autoparts stores can cross the Motorcraft part number (RT-16) to the brand they sell.

Thermostat Gasket: B5A-8255-A

This is the only thermostat listed.


>> CAVEAT EMPTOR: The early thermostats are LARGER in diameter, than what was used after 1967 (on trucks).

>> Flange diameter is 2 1/2" <<

Brian = The only radiator cap listed in the parts catalog is a 4 pound cap. Try and buy the type with a handle that lifts up to relieve the pressure..

 

Thank you sir. Both of you. I have the parts now. Napa had to check their car books to find the thermostat.

The engine is cooling a little now as we speak. I washed a ton of gunk out of it when I opened everything up originally. I then added the "flush" stuff and ran it for a while.

Saturday is getting too close for this.