I had the A/C recharged in a 2002 prius, but it quickly discharged and is blowing hot air again. Given the rate of discharge, I suspect the system has neutral air pressure (totally depressurization) and has had it for a long time. Is there a way to test for leaks with a simple air compressor and soapy spray like you would to check for leaks in a tire? I'm hoping it is in an easy spot like a schrader valve (as opposed to somewhere like in the air compressor). I can just the valve with some air and spray around looking for bubbles. I hear it's usually at a valve. What is the system like in a 2002 prius? Is it just a schrader valve there or is it a special system with some other kind of fitting?
First some cautions. The system on the Prius uses a totally different lube from other automotive system. Absolutely no PAG oil!!!! Don't use equipment that's been used on conventional automotive A/C. It's contaminated and using it can cause a whole world of hurt. It's a standard R134a fitting. This is the tool I bought specifically for my Prius 1. A/C Pro C Pro / Recharge hose and gauge - Not for Hybrid vehicles with electrical driven compressors ACP-400- ReadReviews onA/C Pro #ACP-400 upload images Note that it has a gauge, a trigger, and an easy to use R134a low side connector. The trigger seems to hold pressure, I've had a pressurized can of pure R134a connected for about 3 weeks One can of R134a will fill the Prius 1 system, you want to use the plain refrigerant, no sealers, dyes, or oil charge. I guess I'd take the car to a standard A/C shop, fill it with your recharge equipment and let them use a freon sniffer to find your leak(s), but don't let them replace any o-rings, they'll want to lube them with PAG oil. I keep my new filler in a ziplok bag when not using it. You can get a pretty good freon and halogen detector from Harbor Freight for $69 minus 20%--a nice tool to have. Electronic Freon and Halogen Leak Detector Best, tho, to take it to a hybrid shop, either Toyota or an independent. With the engine running and the A/C on and set to its coldest, give the system short shots of R134a. You don't want to over charge, so anything over about 36 psi at the low side connector is not advised. Trying to find the leaks with soapy water might work, but doing it with a sniffer is a better solution. If you replace parts, you'll need to pull a vacuum, and I think the best thing is to let a Hybrid trained tech do this work. Hope this helps.
This is a thread about the Gen 1 A/C system, in the Gen 1 forum, so that doesn't apply. The high-voltage electric A/C systems requiring ND-11 oil started with Gen 2. The conventional, mechanical compressor in Gen 1 uses ND-8 oil "or equivalent" (see page AC-49), which seems often equated to PAG-46 (I'd be more sure I found an actual Denso page that says so, and I haven't, but vendors seem to agree about it). And yes, if you have a Gen 2 or later Prius requiring ND-11 oil, then be sure to use only that. But this thread's about Gen 1.... -Chap
I wanted to use soapy water to check for air leaks because I don't want to spend too much money on this. I'm hoping it's at an easy to repair place, like a schrader valve. If it's leaking at the compressor, then I won't bother. Too much money for parts and labor, but the schrader valve I can repair myself nearly for free. In any case, if I decide to use regular compressed air just to put a bit of air pressure in the system, where would I put it?
Thank Chap for the clarification. Primuspaul, I don't think I'd be using compressed air to diagnose a leak. Would not be a good thing to inject moisture and contaminants into a closed system, plus the high and low side shrader valves aren't even close to the size of a tire valve. And low pressurization of the system, say about 10 psi wouldn't cost much and you probably could get any neighborhood garage to sniff the system for leaks--probably charging nothing.
