Don't Know How Much Refrigerant My Truck Takes

['89RangerBoi]

Hey everyone,

I'm recharging my truck's ac system, but I don't know how much refrigerant it takes. The tag that's supposed to be in the engine bay isn't there (I believe it came off when a previous owner had it, as there are marks where other stickers have been). I have a 1989 Ford Ranger XLT (4x4) with a 2.9L V6 engine. I was wondering if anyone has the same truck and could check the sticker on their car for me, or if anyone happens to know how much refrigerant my car takes anyway. Thanks, all.

By the way, I believe the system was already retrofitted to accommodate an r134a system, so I will be using that refrigerant.

Thanks.

 

[Uncle Gump]

So I moved this post and deleted your second. There is only need for one post on a given topic.

I'm cooking some dinner but if you don't have an answer when I'm done... I'll try to help you out

Sit tight... many here are pretty well versed in these A/C systems.

 

[Uncle Gump]

So is it completely empty?

Did you change parts?

Repair leaks?

Pull a vacuum on the system?

Do you have a/c gauges?

 

['89RangerBoi]

I bought the truck with the ac compressor out, so yes, the system is completely empty. The ac compressor came with the car. I was planning on renting a vacuum pump and manifold gauges to clear out the system, and then recharge it with the correct amount of refrigerant.

 

[Uncle Gump]

Gotcha...

If the system was open for any length of time... or especially if the compressor blew up... you should really flush the condenser evaporator and lines. There is likely junk in them. You really need to replace the accumulator and the orifice tube also.

Did your replacement compressor come with oil in it?

 

['89RangerBoi]

I don't believe it has oil in it.....

Any particular flush I should use?

 

[Uncle Gump]

I'm also gonna ask @franklin2 and @RobbieD To jump right in. My Service Manual on CD like self destructed so I don't have access to the actual fill amounts.

 

['89RangerBoi]

Thanks!

 

[lil_Blue_Ford]

Yup, everything needs flushed and you need an accumulator and orifice tube. You also will need adapter fittings if the truck doesn’t already have it to go to R-134a. Original for your truck was R-12 and a mineral oil charge. It’s no longer available so you need PAG-46 oil if memory serves correctly and R-134a for the charge. I don’t have the amounts you’ll need handy, but I believe it’s something like 8oz of oil and three 12oz cans of R-134a but you’ll actually only use two cans and a partial.

 

[Uncle Gump]

I don't believe it has oil in it.....

Any particular flush I should use?

Most box stores have flush kits and any of them should do the job.

 

[RobbieD]

The AC system sticker on my '90 is right on top of the evaporator housing on the firewall. I've also looked up the charge and oil charges in the 1989 shop manual for you.

Refrigerant charge capacity in the 1989 manual calls for 32 ounces of R-12. On a converted system a rule of thumb calls for 90% of that, or about 29 to 30 ounces of R-134a.

The oil charge is listed as 10 ounces. As mentioned, mineral based oil and PAG are not compatible. In case of a leak or component replacement, you can either drain all of the oil or estimate the loss from a leak or component replacement and add that estimated amount.

A new accumulator and orifice tube is the norm.

I believe the system was already retrofitted to accommodate an r134a system, so I will be using that refrigerant.

I hope that the system was retrofitted, and done right. Tough call on what to do here. You could just charge it with 134a cans which include oil and see if the system actually works.

I'm just leery about putting too much stock in a system that is said to have been converted. Did you dump the charge yourself, or did you get the truck with it needing a recharge?

If the system wasn't converted properly, or not flushed completely of the original oil, it won't work properly, or just flat-out fail. In that case, any new parts that you put on it, like the accumulator and orifice, will be wasted money. And, in that case, you're pretty much looking at replacing everything to get it right again.

A good, trustworthy shop that does, and knows, older Ford AC systems may be worth considering in this situation.

 

['89RangerBoi]

Thanks for the help. I was planning on playing it safe and just flushing and vacuuming the system just in case it hadn't been retrofitted.

 

[RobbieD]

Good luck. I hope that it goes smooth, and gets you back into the frosty chilly breeze.