AQ130C: Replacing upper water drain tap

[am_dew]

I need to replace the upper water drain tap on my AQ130C engine. I have the part I need...is there anything special about doing that or I need to be concerned about when removing the old one and installing the new one? Thanks.

 

[joe_merchant]

From my limited experience, it would be a good idea to clean out the threads in the block and then use some pipe dope to help seal it in. That little brass petcock is a spendy little sucker!

 

[am_dew]

Thanks Joe. I was able to pick up a Sierra drain for less than $10, which I thought was pretty reasonable.

 

[am_dew]

Well, I got the job done however it took some customization to make the new drain to work. The obstacle was in the sunken nature and immediate surrounding area where the drain screws into on the engine block...the female threads of the hole on the block are sunk down into an opening on the block that was not big enough in diameter to get a socket on the OEM replacement (Sierra) drain in order to screw it into the block (see pics A and B below). I ended up having to add a 1 inch long 1/4 npt nipple (male on both ends) in the block and then attached to that a 1/4 npt female-to-female fitting and finally the replacement drain was then screwed into that (final pic).

The drain I replaced (non-OEM, replaced my a mechanic several years ago) had a 1/2" space between the male threads and the area that you would put a socket over to tighten it down, so it stuck up high enough out of the hole to get a socket on it.

The joys of boats...

Pic A (threaded hole in block)


Pic B (same hole with Sierra drain loosely screwed in)


Final outcome

 

[joe_merchant]

Seems like one of those "5 minute jobs" that leaves you asking why things can't just be simple .

 

[am_dew]

Seems like one of those "5 minute jobs" that leaves you asking why things can't just be simple .

Isn't that the truth!

If the pics of the OEM replacement drain I've seen online are accurate, it looks like it has a "shoulder" that extends up high enough so that a socket or box wrench would be able to grab on to it so you could snug it up into the block. Why the Sierra replacement is so short is anyone's guess.

OEM 82745


Sierra 18-4218