A/C performance declining

Yes, R-134a is the correct refrigerant. You can look at the sight glass which is in the high pressure line (near the windshield washer reservoir) to see whether bubbles are present when the compressor is running. If you see this then the refrigerant is low.

Use a low pressure gauge when adding refrigerant. The spec is ~29 psi which is lower than most vehicles.

If the refrigerant is low, your system probably has a leak so adding refrigerant is going to be a short term fix.

 

It just so happens that Mendel got carried away and posted relevant pages from the service manual in another thread tonight. It's from a Gen 3 but the things to look for in a sight glass test don't seem to be different (even from Gen 1) so you'll probably get a pretty good idea how to tell if refrigerant amount is your problem.

-Chap

 

if the Freon is OK try this video to see if you have a blockage in the system..

It helped me find a bad condenser so I replaced it myself with one from e bay for 65 bucks some oil and Freon now my ac is blowing 47F at the vents in the florida heat..shop wanted $100 just to trouble shoot it if I didn't let them repair it

 

add some dye to the system if its low, the dye is fluorescent green and is easy to see usually even without a UV light, unless the leak is very small.

 

That's kind of interesting. I can't help thinking how much faster he could spot a problem like that using a thermal imager, instead of trying to wave a spot temperature gun over the whole condenser face and see where the readings change. Anybody else notice that FLIR recently demolished the price barrier on imagers?

I confess I have real trouble taking that Kilmer guy seriously ... not after seeing one of his Prius videos ....

Ferinstance, how many of you knew that when your Pri isn't charging the 12 v battery, it probably isn't the DC/DC converter, but because it's "very common" for the generator "inside the transfer case" to "overheat and melt"? The whole thing has to be seen to be believed. Especially because for his spiel to make any sense, he would have to be talking about MG1, not MG2, and yet somehow you hear it crank the ICE ... then he ends up talking about replacing the trans[ok, axle] for a problem almost certainly in the inverter. And it wouldn't be complete if he didn't keep pointedly saying the Prius "generator" isn't an alternator (we know we all say "generator" in the Prius world, but last I checked the 3-phase AC coming out of it would not exclude it from the alternator club).

On the other hand, it's good to know that when you change the coolant pump that cools "the inverter and the hybrid battery in the back(!!)" (but somehow not those melty MGs in the transfer case), you can just dump the spilled coolant back in and drive away without any bleeding or anything. I admit, I never learned any of that from the manuals....

I make a point of never thinking there's anything wrong with not having a clue what you're talking about, since we all start there ... but taking stuff he so gloriously doesn't understand, packing it up in the voice-of-knowledge and putting it on youtube for people to stumble on ... that bugs me.

I do not know, maybe he's right about the condenser. If he thinks it's clogged with crud, I'd have liked him to say more about what kind of crud, or where he thinks it came from, or what he thinks'll happen to the new condenser he just put in without flushing anything....

-Chap

 

its a matter of cost..$20 temp gauge $2000? imager ...all I know is it worked for me..

 

There's one person so far who hasn't followed the 'demolished price barrier' link....

-Chap

 

I don't have an I phone and I already had the temp gun....
somehow I doubt that app is any good when a real unit is well over 2 grand..
that's like the x ray specs in the back of a comic book

 

It's made by FLIR, one of the best known outfits making the "real unit". (Even the prices on their "real unit" have been dropping ... you can get a refurb i7 for ~ $1500, etc.)

Their technique for exploiting hand-tremor to recover 160x120 thermal resolution (better than an i5, comparable to i7) from an 80x60 bolometer is clever, and also mathematically serious. In other words, clever-like-Prius-heretical-mode, not clever-like-woo. (It just doesn't work so well if you clamp the thing on a tripod.) Of course, they could eventually apply the technique to their higher-end imagers too....

-Chap