deen2vaca

I have a 1985 Toyota pickup, 1Ton that needs the AC in working condition. It sat for about 3 yrs and I now have it in running condition again without much trouble. The AC is R12 so I'm converting it to R134a. I starting putting in the freon today and heard a large leak. I found it on the top of the dehydrator. It has a hole in it that makes it look like something is suppose to be there. Here's a couple pictures of it. If I put in a new dehydrator, what else would I have to do to the ac system to have a chance of getting it to work again? Any ideas?

old87yota

Welcome to YotaTech!!

Here is a good video that goes through recharging A/C systems from empty. A/C work is more complicated than dumping a can of refrigerant in to get the system to work properly.

I hope this video helps. There are also other videos on YouTube that cover this too.

Good luck!

deen2vaca

Thanks for the link. I still need clarification on what is suppose to be in the hole in the top of the dehydrator.

old87yota

Sorry, I have no idea about that hole as I do not have air conditioning in my truck (yet). I would get a new dehydrator (or receiver/drier) and see if the new one has the same hole or not or see if there is a fitting that is supposed to go there. Maybe someone with A/C can go out and take a look at their truck to see what is supposed to be there.

reelal

That's supposed to be a window of glass so one can see the ref. going thru the drier. Put in a new one, pull a vacuum for about an hour, that should boil away the moisture, then close the valves on the gauges on watch too see if there are any more leaks. By the way when that glass looks clear, no bubbles, the system is full of ref.

millball

I'm not so sure about that.

Sight glasses are most often found on the high pressure side, not on the low pressure side.

More likely, the hole is to accomodate the suction side low pressure/low charge cut-out sensor.

old87yota

Other sight glasses I have seen are right on top of the receiver/drier where the hex socket is in the first picture. It is hard to tell, but it is possible that the indentation is a sight glass but like I said, it is hard to tell from the pictures...

ZXT

There's supposed to be a plug in it (see the picture of the one on my truck)

Go buy a new one. They're referred to as receiver driers/accumulators. With yours open to the elements like it was, the drier is dead. If you try to charge it with the one on there, the innards will likely come apart and spread crap all throughout the system.

Hopefully since the opening is in the drier, it has kept dirt/bugs from getting into the rest of the system. If it were me, while the system was apart, I would flush it with rubbing alcohol (90%) and compressed air to get the debris out. Obviously, use new o rings on the fittings when you put it back together and while you're at it, changing the schrader valves in the high/low ports wouldn't be a bad idea. They get old and leak, and they're only a buck a piece.

Since its been open for who knows how long, pull a vacuum on it for at least an hour or so. Shut the pump off, close the valves on your manifold set and it should hold a vacuum. Some leakage is to be expected from an old system, but I wouldn't be happy with more than 1-3 inches over a 2 hour period. Letting it sit overnight would give you an even better indication of the condition of the system. It will also need oil added to the system, as most will be gone after changing the drier and vacuuming.



If it's completely tight and doesn't leak off any, I would put R12 back in it, because it will cool better. Otherwise, use 134. It will work fine going down the road, but sitting still the performance will be poor.

EDIT: After posting, I see that yours does have the plug but has a hole in the center. Maybe it was some form of high pressure relief? Anyways, a new one should come with it.