98 F150 Radiator Flush - Block Drains

I'm trying to flush and refill the coolant in my 98 f150 v8. The radiator flush is fairly straight forward, but my Hayes manual and other info from the web tell me to drain 2 engine block drains which i can't seem to find.

Several sources refer to the block drains as being a 17 mm bolt. Others says you need to use an allen wrench. I have found something for an allen wrench just above the oil pan on the driver side but can't budge it. There isn't a similar drain on the passenger side which makes me wonder.

Questions:

Is there another way to drain the engine block? Disconnect hoses? Which ones?

Can I just drain the radiator, fill with water, run for a little while, repeat the process a couple of times....then fill with new 50/50 mix?

Any help would be appreciated.

If the block drains are stuck (a common problem) I just pull off one heater hose and the bottom radiator hose. I hook up a garden hose to the heater hose and turn the water on. Water come out the bottom rad hose and the other end of the heater hose. I let the garden hose run until water comes out clean and clear.

Depending on your engine configuration I disconnect any other heater hose connections and the intake manifold bleeder screw (if equipped) and see if the water also comes out clear. I flush the rad with water and make sure it drains.

Then I disconnect the hoses to the heater core and flush it with cold water in the opposite direction of the coolant flow.

After doing this, I have used compressed air to gently push any clean water out of the system. It will have some minerals and the less water remaining in the system the better.

Then I hook everything up again except for the bleeder screw. I put in straight coolant to make up about 60% of the rated coolant capacity for the system as per the owners manual and fill the rest with a measured amount of distilled water. I make sure the overflow bottle is topped up with 60/40 coolant/water and the bleeder screw is tightened after the air is purged from the block.

magic rat...I wish I had your know how....a couple of dumb questions:

I can figure out the upper and lower radiator hoses.

As far as the heater hoses...how many are there? Where are they? You say just pull one off...is there any harm in pulling the wrong one off?

In a nutshell, am I just disconnecting enough hoses in 2 different areas in order to be able to flush out the system?

Update:

Unless you have a special tool or pygmy-like hands, getting either of the heater hoses off is nearly impossible. Similarly, the lower radiator hose is in a spot that takes a lot of work to get off.

Instead, I bought a $3 flush kit which involved cutting the inlet heater hose and installing a tee. I hated to cut the hose but figure hoses go bad anyway and would probably need replacing at some point anyway.

FYI....Ford makes it very difficult to find out which heater hose is which. After a lot of searching and checking for hotness...the hose on the inside, closest to the drivers side is the inlet to the heater core.

I installed the tee in about 2 minutes, unhooked the upper radiator hose, connected my hose and flushed the system out till it ran clear. I have hard water in my location so I did take my tiny air compressor, put it in the tee and blew out quite a bit of water. I have no idea if I got most of it, but there was plenty coming out.

refilled with 50/50 mix of distilled water and Peak coolant.

Keeping my fingers crossed....