I am trying to figure out which is the coolant drain bolt. The Service Manual is not entirely clear to me.

Is it this: Honda 90001-PM3-003 Bolt, Drain Plug (28MM)?

 

Are you referring to the one at the bottom of the radiator, or an engine block 'freeze plug'?

When I Googled the one you listed, that looks like a metal plug, which would be for the engine block. The one on the bottom of the radiator is typically called a 'petcock,' and is plastic with a blade-type of grip on the end that you turn counterclockwise to back it out and drain the coolant from the radiator.

What the one on the radiator looks like:
https://shop.advanceautoparts.com/fi...or-drain-plugs

 

^^This.

Although I do not know why you are calling it a "freeze plug." I've never heard of that term.

 

I was under the car yesterday, and I could not locate the coolant drain bolt on the engine block. A buddy of mine in the shop said it was the one just inboard of the drive belt tensioner. It has a wide washer on it that looks like it is part of the bolt head, and it had a dab of red paint on it. It seemed pretty high up on the block for coolant draining, but that might be it. Needless to say, it is impossible to reach.

 

It's a remnant name from the good ol' days. The freeze plug was a sacrificial exit for water from the engine if temperatures dropped and the water started to freeze and expand. In other words, blow the freeze plug instead of cracking the block.

I don't see how the bolt you're looking for could serve that purpose in a Fit. It is, however, the bolt you remove and replace with the heating element if you install a block heater.

The block heater install instructions (GE8 instructions attached) might give you a better idea of where it is and how you approach it for removal.

 

@Drew21 Brilliant, Drew. That's the bolt that my buddy pointed to, and your block heater PDF (Step 6, Page 3) identifies is as the Coolant Drain Bolt. Bravo, sir. The PDF says it's a 19mm. I wonder what the part number is.

By the way, I could have saved us both the trouble if I had remembered my old friend @Pyts posted on this subject five years ago.

https://www.fitfreak.net/forums/2nd-...nary-tale.html

As I reflect on all my years of driveway maintenance and all my cars, I do not recall that I have ever been able to remove the coolant drain bolt on any car. It appears that the Japanese make it a matter of policy to cement these bolts into the block.