Just to update this thread, used it for reference and to create a similar setup. Thought I'd share where I got my parts.
Amazon for the pump. $50
Home Depot
- 1 1/2" x 3/4" pvc fitting, and a
- 1 1/4" x 3/4" fitting,
- 2 of 3/4" NPT x 3/4" MHT fittings,
- a female to female hose remnant (7' I think), and another short hose for the exit side
- Plastic trash can or 5 gal bucket
- total maybe maybe $25
Grocery - 4 gals 5% Vinegar - $10
I put the water pump and EMPTY thermostat housing back on with some black RTV (I didn't waste a new gasket for this), and have been running the straight vinegar for 24 hours now. Used CLR the first time and over 8 hours it didn't do much, so plan on running it for several days with a very mild acid like vinegar.
Some people have talked about using muriatic acid, but that is extremely harsh and may cause some embrittlement of the underlying metal, plus it will eat up your hoses pump and water pump and thermostat housing, so it's not recommended by others. I chose not to use it.
It is also recommended by someone more knowledgeable than myself to run it for a couple of hours and let it sit overnight or for a period of time and then run it again and then let it sit etc. until you are satisfied with the results.
I've also noticed that the vinegar tends to evaporate pretty quickly and so I have added a little water to the mix. However, when it evaporates the acidity will increase, so you may want to just let it evaporate a little bit as it may speed up the process.
Hope this helps.