toyotafan

I bought my '96 tacoma about a year ago, but the a/c has never worked. I looked through the glass on that front unit (receiver dryer?) and looked low so I added freon. The compressor kicked on but kinda blew cold air for about a minute or so and then shut off. I could smell the freon so I know I have a leak. I tried putting in the dye to help find it, but couldn't locate it. I'm guessing because it's my evaportator that has the leak and it's pretty well hiden. This all happened a year ago. Then the other day, I tried stop leak along with some more freon and I actually got some white dust blowing through my vents and compressor didn't even kick on. Would anyone like to guess if it's my evaporator? I know I won't know for sure until I tear into it, but wouldn't mind some guesses/tips from you all. Thanks in advance!

FattyCBR

Do you have a body lift on the truck or was one ever on it? There is a hose that goes between the engine compartment and cab that gets stretched and cracked with a body lift.

toyotafan

Appreciate your reply. There is not currently a body lift on it, but doesn't mean there wasn't at one time. I am the 3rd owner. If that were the problem, sounds like a pretty easy fix. I do think that hose you mentioned or the evaporator itself is the problem. I'll be tearing into it soon to find out. I better fix my wife's honda a/c first, however, before she blows a gasket. The heat here in N. Utard is in the 90s and getting hotter!

FattyCBR

Good luck finding the problem.

Shane

They dye you were using, was it the type that requires a blacklight (UV light) to see it and if so did you use one? Have you tried spraying some soapy water on all the hoses and fittings to find the leak?

toyotafan

Shane - I actually looked on the package when I bought the dye and it didn't say UV light required and that's why I bought it. Today, I tore into the evaporator and expansion valve, but not sure how to tell which part if not both are bad. I probably shouldn't even be doing this kind of a/c work, but just hoping to find something obvious and I do like to learn new things. It looked like there was some seepage of freon inside the box that holds the evaporator, but couldn't find anything obvious on the components. Is there a way to determine if an evaporator and expansion valve is good or not or do I need to just take it to a professional? I'm selling the truck, but thought it'd be nice to try and get the air going rather than selling as is. Appreciate any advice or comments!

Shane

I'd say take it in and have the pros take care of it for you.

PhxTRDRunner

Yup, my thoughts exactly...to do a/c correctly you need special equipment 99% of do it yourself'ers don't have.


Good luck!

Shane

Not to mention you have to be certified in order to get your hands on R12 these days.

Jay

Yes, Reciver Dryer. And Just to be clear.... Bubbles in the sight glass mean its low, Clear sight glass means full or empty. Shutting of the a/c and observing the sight glass for a rush of bubbles will tell you if its full or empty.

Refrigerant is odorless. Perhaps you smell the oil?

Peel back the foam insulating wrap on the evaporator inlet/outlet tubs, check for a hairline fracture. If I remember correctly, it will be near the bend in the tube.

shovelhead

look for a wet spot , usually when there is a leak the freon will carry system oil out with it, do you have R12 or R134A? I suspect 134A ,that makes it a little harder to find but you should still see the leak

Shane

Ah, didnt' see he's got a 96. 134A is easier to find... it's R12 that's disappearing. Or do you mean finding the leak? 134A does leak out easier, an old hose can be porous enough to lose it over time but I think he's got a bigger leak than that.

shovelhead

finding the leak is a little harder because 134A can be installed with different oil : pag, ester or synthetic ester.where 12 uses mineral. and it can be a little easier to find ( at least that's been my experience)

toyotafan

Jay - Appreciate everyone's advice. I actually did what you suggested (peeled back the foam wrap on the evaporator inlet/outlet tubes) and did find freon/oil. It is very diffult deciphering where are on the tubles it's coming out, but with a hairline fracture is it possible you can't really see it. Also, is it possible that the evaporator could have a leak and throwing freon out onto the tubes? I know I've narrowed it down to 2 possibilities, but want to be certain before buying parts. Thanks for all your help/advice!