Does anybody know what size the 2 hoses are that run to the firewall for the heater core? truck is a 1993 f150 5.0 4x4.
thanks.

--edit--

i have another problem maybe yall can help me with. the drain plug on the bottom of my radiator seems to be plugged up because it is not draining. I took the little wing nut completely out yesterday and the coolant just slowly dripped out. Any recommendations on cleaning that out?

 

They're probably 5/8", but it should be printed on them. Any parts store can match them.

If your radiator has so much sediment that it won't drain, you're not going to clean it out without ruining it. A good aftermarket radiator can be had for <$200 with LLT warranty. Mine is a Modine from Advance, and I've already swapped it once free.

 

Well actually I did get it cleaned pretty good by running cleaner through it. And from looking around on google it seems like a ton of people have that problem and they all just drain using the bottom radiator hose. My new question is if I pull the bottom radiator hose and drain that way, how much of the coolant will drain from the system? obviously the radiator will empty but how much will empty from the block?

 

Most. Enough. If you want to get it all (but there's no point), run water into one of the heater hoses to rinse the block out thru the open lower rad hose.

But the real question is: if the drain is plugged, how many of the cores are? To find out, remove the fan & clutch (replace the bolts to hold the pulley on, but don't let them hit the WP housing), wet the radiator, then start the engine & let it warm up. When the t'stat opens, the radiator will dry suddenly, but only on the cores that are flowing. If more than ~1/4 of the radiator stays wet, I'd replace it.

 

Ok thanks I'll keep that in mind. I think I've got it good enough that it will be fine for the winter then when it warms up again maybe I'll do all that.

 

...and it's so much easier to change a crapped out radiator when it's 20 below zero than it is now.