1991 Explorer XLT ac recharge?

[bigredone]

Looking to recharge the a/c on my 91 explorer. Is it as easy as going to autozone and picking up a can of r134a along with the hose and running it into the low pressure port? Any feedback appreciated. Thank you.

 

[Wolfie_85]

Not unless it's already been converted from R12. They are not compatible. Don't mix them!

 

[natenkiki2004]

It's something that should be done by a professional or a knowledgeable person with gauges. The system is old and could easily be leaking. I'd have it evacuated and then vacuum tested, THEN converted over.

 

[Anime]

No matter what you are going to put into it, either R-12 at $40-80/can or R-134a, you should at the very least have the o-ring seals replaced, since that is usually where the leaks are.

If going to R-134a, you should have the hose assemblies replaced with new ones (the new "barrier hoses" are necessary to trap the smaller R-134a molecules, which are small enough to get through the old R-12 hoses).

You should also have the receiver/drier replaced, and the orifice tube should either be replaced with one for R-134a or a "variable" one. The variable one costs more but can be worth it as it gives better cooling.

If going to R-134a, you really want to have the system flushed and cleaned, you don't want R-12 oil in there to mix with the R-134a since it can contaminate the system.

You can have a heating/cooling place do all the work and replace all the parts, or just have them evacuate the system (if there is anything left in it), then take it all apart yourself, replace the hoses, remove the condenser/evaporator and clean them out, drain the compressor, install new o-rings, install the receiver/drier, orifice tube, etc., put everything together, and take it to be vaccum checked and filled up.


You CAN just throw in a can or two of R-134a, and it might work for awhile, but chances are good it will just clog up and turn to black goo and then you'll have to buy all new parts if you want a working A/C system again.

If you don't want to pay to replace the parts and convert to R-134a, then just have the o-rings replaced and pay the extra $$$ for two cans of R-12.

 

[mekelly]

Convert It!

You can buy new hoses, accumulator, o-rings and orifice tube from Rock Auto for less than $100 more than the cost of the R12!

R-134 is less than $7 a can at Walmart. You can rent a flush bottle at Autozone for free. The flush will run you about $15. Pag oil is $9

Convert is the only way to go in my opinion. You can also rent the vacuum pump and manifold gauges for free. The only caveat is you do need to be somewhat handy and careful as the system is under pressure and serious injury can occur!

I have a 1994 so it was R-134 from the factory but the accumulator and several o-rings were leaking. Replaced the accumulator and o-rings, added oil and 2 cans of R-134. It blows 40 at the vent on an 85 degree day in Atlanta!

 

[larrydd999]

Anime, thanks for the tip on the variable orfice tube. I need to rebuild my '94 A/C system, which has R134a of course. Would using the variable orfice tube be of any value?

 

[Anime]

Anime, thanks for the tip on the variable orfice tube. I need to rebuild my '94 A/C system, which has R134a of course. Would using the variable orfice tube be of any value?

The 1994 R-134a system is, in reality, a factory-retrofitted R-12 system, with the additional benefit of a pressure sensor in the main hose line (at the filter), due to the higher pressures of R-134a over R-12.

I would guess that the variable orifice valve would improve the cooling ability of the system due to this, but plenty of sites for the VOV also tout them as an improvement for factory R-134a system in more recent vehicles, so if that's true, I don't see any reason not to use it on the Explorer.

The only thing I would caution you is to be sure and get the 'standard' variable orifice valve, and not the (more expensive) 'severe duty' orifice valve. The severe duty version is for use in climates that regularly see temps over 105+ degrees or so, and it seems to be pretty restrictive or at least presents the very weird risk of the orifice valve being pushed out of place and into the receiver/drier due to system pressure. Maniak had this happen on his rig with a bang when the valve broke loose inside the tube and had to crush the orifice tube on the receiver/drier to hold the new tube in place.


I should also suggest you use Nylog on the green o-rings to seal up the system when rebuilding it. Seems to be worth it for the minor expense. Be sure to get the "HFC" kind with the blue lettering for use with R-134a, the red lettering HFC-HCFC version is for use with R-12 and R-22 systems.

Also suggest you get genuine DuPont R-134a cans if going the DIY route when refilling, not cheaper stuff, especially anything with leak sealant or dye. I've found it at some auto parts stores, and it isn't any more expensive than the R-134a anywhere else, or if it is, they will usually match the price of the parts stores around them. The other brand name R-134a with no sealants or dyes is ok, just hard to find since the major parts stores generally carry gimmicky stuff, guess it sells better.

 

[mekelly]

Agree with everything but the recommendation to go with more expensive R-134a. If there's no additives (dye, sealer, etc.), R-134a is R-134a. Chemically, they are identical. There's no reason to pay $14-$15 dollars a can when you can get it for 1/2 of that at Walmart.

There are plenty of parts for our cars where it makes sense to buy the higher priced (better quality) part. R-134a isn't one of them.

 

[Anime]

As I mentioned, the genuine DuPont R-134a isn't always more expensive than whatever no-name stuff the other stores are selling, and you can usually get them to price match if it is. The price of R-134a went up quite a bit the last few years, so it's not like walmart is selling the stuff at $7-8 a can and the parts stores want $14-15.

Walmart actually sold the genuine DuPont stuff when it was cheap, that was when to get it.

R-134a is R-134a...kinda. The US-made DuPont stuff is guaranteed pure, a lot of the no-name stuff is made in China and is slightly less so. Of course, DuPont makes their R-12 in China (since they can't manufacture it in the US), but that's still DuPont.

It's just a suggestion. You can get away with just coating the o-rings in the oil lube for the system and sticking cheap R-134a in there if doing a rebuild/recharge on a shoestring budget. Spending extra for stuff like Nylog and seeking out the genuine DuPont refrigerant is just a druther if you feel it's worth it.