Hello, all:
With the weather getting warmer and more humid, I have noticed that my A/C is no longer turning on, as in, the compressor doesn't engage when switched on. It stopped working sometime over the winter, and was working last fall. I am assuming that the refrigerant volume/pressure is too low.
In the 4-1/2 years I've owned the truck, I've topped the refrigerant off twice. I have a decent manifold gauge set (from NAPA), and I checked the low side pressure yesterday, and it was only about 28 psi (81 degrees ambient temp).
I am hopeful that its just a bad o-ring or maybe a Schrader valve. Here is what I am thinking to do for diagnostics, and I wanted to confirm with the more knowledgeable members of the forum if this makes sense:
A couple of specific questions:
Tim
With the weather getting warmer and more humid, I have noticed that my A/C is no longer turning on, as in, the compressor doesn't engage when switched on. It stopped working sometime over the winter, and was working last fall. I am assuming that the refrigerant volume/pressure is too low.
In the 4-1/2 years I've owned the truck, I've topped the refrigerant off twice. I have a decent manifold gauge set (from NAPA), and I checked the low side pressure yesterday, and it was only about 28 psi (81 degrees ambient temp).
I am hopeful that its just a bad o-ring or maybe a Schrader valve. Here is what I am thinking to do for diagnostics, and I wanted to confirm with the more knowledgeable members of the forum if this makes sense:
- Evacuate remaining refrigerant and draw a vacuum on the system (thinking of getting the $140, 3 CFM Pittsburgh vacuum pump from Harbor Freight);
- Refill the system with UV dye and 36 oz of R-134a;
- Check for leaks; repair as necessary.
A couple of specific questions:
- Does PAG oil need to be added with a refill, or is that only if I am replacing the compressor with a new, non-oiled compressor?
- Are the o-rings generic? Any preference on brands/kits for o-rings?
- There is something rattling around in the evaporator core housing behind the glovebox when the blower is on. I'll need to open up the housing and figure out what is going on there.
- Are they any "common" leak points on these systems that I should pay special attention too? Specific lines, junctions, fittings, etc. that are more prone to leaks than others?
Tim
