So I took my truck to Firestone (had a coupon and lifetime alignments there) to get the A/C recharged today. This is after installing brand new lines, a new receiver drier and new condenser.

6 hours later, they call me and say they can't get it to work. There's no leaks in the system, but the high pressure side won't put out any pressure. They offered little explanation beyond that and didn't propose any possible solution to fix it. Retards.

What's the possible culprit here? Bad compressor, expansion valve, pressure switch? I'm going to get a hold of some manifold gauges to test the system myself, but this is certainly virgin territory for me.

 

It's possible their gauges weren't working properly, or maybe it's a stuck txv. Be careful using manifold gauges if you've never used them before...you don't want to release any of the refrigerant, which will also allow air into the system. You mentioned you had replaced some components, what was wrong with them?

 

your first problem was going to firestone. They are good for their brand of tires and that's about it. I would get your truck back and not pay for their incompetance. Sometimes the dealer is the best option for this.

 

well, if your static pressure (pressure when the truck/ac off) and pressure when the compressor is spinning are equal, most likely its the compressor. its simply not pumping. your high/low pressures while its running will be the same also. you wont be able to determine this without manifold gauges. i'm not overly familiar with toyota's a/c, i believe they use an expansion valve, which could be bad, but i really havent replaced many of those for breakage. i do agree with dallison, somewhat - using the a/c machine really isnt that complicated, but diagnosing issues after its been filled, and things dont work, require some skill.

 

Midget check and see if the compressor clutch is engaging, if not check the flowing.

1.Is the compressor clutch getting power?
2.If not check the A/C system fuses
3.If they are good then check the high and low pressures switches with a DMM or continuity tester.

Also unrelated to the above but an important question, do you know if Firestone vacuumed out the system before recharging?

The 4Runners and Tacoma A/C systems use a TXV mounted up on the evaporator but I HIGHLY doubt its bad. If a TXV goes out it will either jam wide open or stick shut either of which is make very distinct pressure readings that even a Firestone tech will understand.

The most common reasons for a compressor not coming on are pressure switches or fuses in my experience.



FOG