2 New Ruud AC's 8th Season..One always worked,other gradually lost cooling by end of first season..

Athana

Back then it didnt really sink in until the next year when it started getting very hot as that non working unit is in the part of house we dont really use, so its the main one that always worked that we have on. I tried to get the non cooling one fixed at the begining of last season by a friend of my brother in law who works for a large firm who brought his buddy..they said that the Freon was low and said seems to be a slow leak..He checked with a meter that detects leaks (what ever was exposed) but found no leak..screwed some ducts together that were open..changed a pin or something where line attaches to outside unit.. he added Freon in which I think was 7 lbs..and said hopefully that was it. He gave me the tank at his cost for future use. Total $400.
Cooling soon disappeared and not repaired. Did not try to fix it this year..am afraid to spend money were are short of.
When the Two 4 Ton Ruud units were installed the R410 Line was new and all units new.
Cant the source of leak be isolated..whether its Line..Unit outside or Unit inside. The Units were new and failed in the beginning. How long does it usually take about to find a leak like this?
It is possible to some extent it was damaged on purpose..A local guy was irked that we didn't use his people..(strange neighbor hood but we are in now and all is well).
Secondly..my working unit..the Coils outside Id like to have them cleaned properly and safely..its all we have.What should that cost in general.
Basically I'd love to have the non cooling unit working/fixed and both outside units coils cleaned for reasonable $

ratio

We don't really talk $$$ here, but if you want to save money, cleaning the outside coil is something that you can easily do yourself. Just gently spray it off with a garden hose, being careful to not bend the fins.

And 7 lbs isn't a small leak, it's a large leak. I would've though an electronic leak detector would have found it; if it's not where he did check then it must be where he didn't check. Keep looking.

You're going to have to spend money to get this fixed. IDK how long it's been down, but it does sound like an install issue that should have been caught initially. Have you reached out to the original installer & talked to their service manager? You may be able to work something out, and I wouldn't give up hope on getting it warranted. We are flexible with our warranty, if there is a real install issue but it's been longer than we typically warrant things, we generally take care of it as if it were still under warranty.

pecmsg

The leak can be anywhere. Agreed 7#'s is substantial so an electronic leak detector should be enough. At the very least Infra Red Dye can be injected into the system, it mix's with the oil so is there all the time for future leak checks!

mikeg2015

IF it was “flat” having lost 7 lbs, should be able to find it. Pull hte door off the indoor coil and look for oil spots. Look for more than residual oil around connection where line sets were made.

That being said, I’ve added 3-5lbs and could not find a leak with a detector. Not always that easy.

SOunds like hte ocntractor changed the valve cores. Wonder if the installer didn’t wrap the service valves wit ha wet rag (or remove cores) and they got roasted and are leaking at the stems. Could use teflon tape on the service valve caps.

neilc

I don't do AC, so this is my dumb question of the day,
would Teflon tape work on these valve stems at ac pressures?

ChrisJ

> @neilc said:
> I don't do AC, so this is my dumb question of the day,
> would Teflon tape work on these valve stems at ac pressures?

Shouldn't matter because there should be caps on them with gaskets. Same for the service ports.

ratio

The 'valve stems' (service ports) generally have Schrader core valves in them which have resilient seals both for the valve assembly to the port and the valve seat itself, which can be damaged by heat. These are a secondary seal and as a rule disposable—if in doubt replace it, they're cheap.

The primary seal is, as ChrisJ mentioned, a cap; generally with an o-ring seal but occasionally a metal-on-metal seal. The service ports themselves are a ¼" flare connection, the threads are IIRC a ⁷/₁₆-20 straight thread, unsuitable for pipe dope or tape. Check for the o-ring when replacing the primary seal & again if in doubt replace it. Those several dollar parts (in total!) are all that's holding in several hundred dollars of refrigerant!

John Mills_5

8 year old Ruud likely has a leaking evaporator coil. If registered when installed, still under warranty. You would pay labor & refrigerant. If not, out of warranty you pay for everything.