minor or major
poka
"Renovating" or perhaps "overhauling".
Overhauling a control valve means replacing all of the worn parts to bring the valve to a condition where it will be able to perform as well as it did when the valve was new.
overhauling
Build It Bigger - 2006 Overhauling the Bay Bridge 3-6 was released on: USA: 20 May 2010
Professional Grade - 2010 Overhauling Overdue Kitchen 4-13 was released on: USA: 22 March 2012
From the internet. I think it is discovery channels website.
It is required with some engines.
If you have he intentions of overhauling it then the instructions will be with the kit.
When overhauling an engine, you need to consider the condition of the engine block, heads, crank, and camshaft. Any of these may need resurfacing or replacing, and the cost may be high enough to look at a complete replacement engine.
Disassemble, inspect, clean, replace/rebuild worn parts, reassemble to manufacturer's specifications.