How do you know if valves are leaking on compressor?

[cazaux]

I have an older Lennox 5 ton A/C. For the last few years, I've had to replace the refrigerant about 2-3 times per year-leak in coils. It has always worked. Most recently, it was replaced, but now the A/C only cools at night. Somebody explained to me that this is because the valves on the compressor are leaking and not allowing enough refrigerant to circulate-that instead its mostly staying w/n the compressor. Does this make sense? Also, I was told that even though its an older unit, the most likely cause is that too much refrigerant was put last time and caused a leak in the valves (or the seals?). Does that make sense??

[mxrruss]

Can't help you on checking the compressor. Are you sure the leak is in the coils? One time after I found a leak at the filter-drier connection the homeowner told me the last guy said the condenser coils had a leak a would need to replace entire unit. I think the money spent to add refrigerant 2-3 times a year for the last few years is money down the drain. Better to get the leak fixed even if it means buying a new unit.

[beenthere]

Overcharging can cause damage.

But, we don't know if it was overcharged.

[James G]

illegal top ups

[amd]

Provided that nothing else is wrong with the system, high suction line and low liquid line pressure indicates that the compressor isn't functioning efficiently.

[amd]

illegal top ups

As far as I know it's legal (but not right) to top up small systems.

[beenthere]

illegal top ups

Whats an illegal top up?????