TIA for any help.

Geez, there's a ton of spam in this group, sorry for the pun...

Well, I have a 8 year old house with a unit that was described as a builders
grade 3 ton Trane by the service tech that was at the house today. The house
has been getting overpowered by the heat in the afternoon and I called my
regular guy who does the PMs to check it.

He says I have high head pressure and was 3 pounds low of freon.

My options were.

1- Evacuate, clean and refill.
2- Leak detection
3- Just add freon, hope it lasts the season.
4- Replace the unit.

He says he wouldn't waste money on #1 because the unit is 8 years old and
it's a builders grade. He says he's seen a lot of them go after 8 -12 years.
Leak detection would probably chase the leak to the evaporator, which again,
he wouldn't replace because I've got a 10 SEER unit and if I replaced it
with another 10 SEER unit that would screw me if the condenser outside went.
I asked him to add the freon and the house immediately cooled down and even
though it was 96 degrees today, the house stayed comfortable. I'm happy but
I know it won't last. He said he was able to get almost a full charge of
freon in the unit without the pressure getting way high.

He explained the high pressure is being caused by a dirty control valve
between HS/LS. He says evacuating, cleaning and refilling may help or hurt
and then you still have the leak...

Question is. Is 8 years enough for this "builders grade" 3 ton Train unit or
should I consider getting the system cleaned, recharged and find the leak.
If the leak is in the evaporator, should I then consider replacing the whole
shebang.

Thanks Much.