When the temp outside is about 80 or hotter the ac doesn't cool off the car. What could be the problem?

 

When it is not working, open the hood (leave engine running and A/C button pressed) and see if the compressor is engaged. Also check if the condenser fans (on the radiator) are running, and if the suction pipe (that starts as a hose at the firewall, then changes to metal and goes over the engine and down to the compressor) is cold or not.

When it works good until the weather gets hot and/or the engine warms up, then the compressor does not engage, the first thing to consider is the compressor clutch gap.

 

Is it blowing somewhat cooler air? I would check the refrigerant charge with gauge set. Too much or too little of refrigerant wont cool good.

 

This is what is listed on the repair bill.
A/C Hose-Comp to Cond Hon $39
R134A Freon
R134A Oil with Dye
Shop Supplies $5.26
R&R Ar Cond Hose, one 1 hour $90.00
Evacuate & Recharge 1 hour N/C
A/C. Install oil with dye. Check for leaks.

This was after I took it in three weeks earlier for the ac not blowing out cold air. When I took it back in he showed me a piece of metal that had a slight bend in it. He said he thought that might be the problem. He installed a new one. Now he says that it might be a relay. Which type of relay do I need to buy? Online I see so many different ones.

 

If this mechanic can not figure out what is the problem with your car in front of him, I would fire him. He's a change-neer. Change parts till problem goes away. Equally as bad as some engineers.

Take it to some place else.

 

I agree, go somewhere else or do it yourself. If the system works properly sometimes but the compressor doesn't engage at all other times, it is not a refrigerant problem. You need to check if the compressor is engaging or not.

 

To see if the clutch is capable of engaging, with Key Off, Engine Off, you could supply battery voltage to the coil.