coolant in AC system?

[travisunderwood]

1988 FJ and went in for AC system check. The shop said that there are mixed fluids in with the AC system. I know very little about AC systems and confused on how how mixed AC fluids would ruin the system They say it needs a new compressor and all.

 

[Texx]

Unlikely they would be mixed, you have either R12 (the high dollar original stuff) or R134a (the lower priced new stuff). You can't put 134 in through the original fittings...check and see if there's an adapter screwed onto your compressor's suction/discharge fittings. If so, someone may have tried to add 134 to the old system without evacuating it. You do need to flush between the two, as the oils are not compatable. They may be right...second opinion?

 

[cruiser_guy]

Very easy to mix the two if it was someone who was not paying attention. It's also possible that it is R12 plus some of the intermediate stuff folks were using for a while like R406 and a few others. Also R134a can use two different lubricating oils and those two different oils are NOT compatible.

Make sure it's flushed WELL and a new filter/dryer goes on too!

 

[travisunderwood]

Would it make sense that the compressor would be bad if they were mixed? I typically will work on most things, but I have zero ac experience. They are quoting $1200 to fix it - and typically this would be an easy no. However being in Phoenix, AZ makes it tough without ac.

 

[cruiser_guy]

Yes, it makes perfect sense that the compressor would be bad. You mix two INCOMPATIBLE lubricants and you don't get ANY lubrication or you mix two incompatible refrigerants and end up with an acid or whatever eating up the guts of the A/C system. $1200 sounds a little steep though, what exactly are they doing? I'd assume that would include a new compressor, clutch, filter/dryer, flush and conversion to 134a as a minimum along with a warrantee of some amount of time.

Remember though that my cost here in Central America is usually MUCH less than it would be up north in the USA so $1200 might not be too bad!

 

[Texx]

You need to find a different shop. At the very least, buy and install the compressor, drier, etc. on your own. Don't connect the lines, so they can flush the system, and don't connect the electrical on the compressor. At least you're saving the labor to install the parts, and you won't have to pay their (apparently)) highly inflated price for labor and compressor. buy your compressor at oreilly's or some such, most have long warranties. You'll have to buy the drier and expansion valve for the guarantee to be in effect. Shouldn't cost more than a couple hundred bucks to have someone flush, evacuate, and recharge with 134a. Compressor and parts out the door should be around 300, your labor and the charge should get you out the door under 600.

Would it make sense that the compressor would be bad if they were mixed? I typically will work on most things, but I have zero ac experience. They are quoting $1200 to fix it - and typically this would be an easy no. However being in Phoenix, AZ makes it tough without ac.