I jumped the low pressure switch and the compressor engaged. What next? Obviously it is low on refrigerant but I do not want to fill it with $70 in gas just to lose it in a few days. How much of the dye refrigerant do I need to get the compressor going and accurately check for leaks?

I will probably be picking up a manifold gauge set here pretty soon. That should help.

Dumb question... is it safe to put about 100 PSI of air into the system and seal it off to leak down test it over night?

The truck is a 99. Is it normal for a 12 year old vehicle to lose all of its refrigerant?

Lots of questions... Thanks for the help.

Eddie

 

Yep, low on refrigerant.

One can (about 40 bucks) should be enough to make it run long enough for the dye to show up. Just need the right light. (so the dye is visible.)

If you pump air into the system, you will have to evacuate it all out before putting in refrigerant, else, the system will not perform well. 100PSI shouldn't be a problem though.

Yep, seals get old, dry out, evap cores, and condensers fail for any of a number of reasons. Lines fatigue, and develop leaks, the crimp connections are a common failure as well. Just like on power steering lines.

 

I'm betting the evap core is leaking. Unless you can change it yourself ,and have all the equipment to evac and recharge. I don't suggest you use dye or stop leak. The AC shop will not be happy.

 

Pull a vacuum on it to test it to make sure it is tight or has a leak.....Am I the only one that believes in using the proper tools and procedures?

If it will not hold a vacuum, it will leak.

 

Thank you guys for the help. I realized after my post that pulling vacuum was probably a better idea than using pressure to test for leaks. At least I didn't say hydro test.

I do believe in doing things right but unfortunately I was not born an AC technician so here I am asking goofy questions trying to learn the right way.

Thanks.

Eddie

 

That's how we all learn.

 

Pressure is a bad idea as stated. But vacuum will only tell you if you have a leak or not. It won't tell you where the leak is. Which is where the proper equipment comes in to play. If it is the (most likely) the evap core, using dye will not help you find the leak.

 

unless you're going to buy or steal a vacuum pump and gauges, you're unlikely to make anything good happen. you can find the AC tools on ebay and pawn shops for pretty cheap. don't get the supercheap vac pump that runs on compressed air. no personal experience but i've never heard anything good about them. get the elec pump or don't bother.

you can dump refrigerant and dye in and try to build up enough pressure for it to keep running without the jumper. but - you may damage a good compressor in the process.

my advice is to either get the pump, gauges, and a how-to book, or else take it to an AC shop. compressors are expensive, more expensive than the tools.

 

1. Vacuum can give false readings with A/C. Compressor seals will test good on vacuum. But, as soon as pressure is put to it, they will leak.

2. How will using dye not help in finding a leak?

 

If the evap core is leaking, you won't be able to see the dye, unless you disassemble the dash. If you go that far, you might just as well replace both cores.... not an exercise to be undertaken lightly.....