I have a 1987 6.9 diesel and had the motor out a month ago its a old ambulance
e-350 i want to charge the a/c back up so when i open the hood to the right there i a valve there almost like a valve stem is this where i put in the 134a
it used to be r-12 so is there a adapter to hook the gas up to get in there
thanks for any help.

 

better off taking it to a shop and get it done the right way. they will probably want to change the dryer too as it will need different oil put in it.

 

sorry i should of mentioned it already had 134a in it and worked great but i had to emty to pull motor. thanks

 

A/C gauges and hoses used for 134a and R12 are different (different hoses, different fittings, different gauges), and because of this, you'll need an R134a guage set to hook up to your 'new' A/C system fittings. Because R12 and R134 are incompatible and contamination is brings disastrous problems, there's no commercially available adapter that allows you to hook an R12 gauge set to an R134 system. Borrow or buy a set of 134a gauges. You're also going to need an A/C system vacuum pump. Pull a 29" vacuum and hold it for at least one hour. This will insure that all trace amounts of moisture are sucked from the system.

Since the system has been opened, go ahead and replace the accumulator/receiver drier. This is simply good maintenance and helps insure that the system runs clean and cold. Be sure to add about 2 ounces of R134-compatible refrigerant oil to the accumulator cannister before installing it. This will replace the oil that's pooled in the old one.

Hope this helps!

 

WHere do you get a new drier that will fit on to the stock hookups and is R134? I just got my compressor working and it needs recharged. How much would a shop charge to change it to R134?

 

Purchase a replacement drier based on application, ie: a 1985 Ford F250. The dessicant/drying agent in the drier works for either type of refrigerant. Add 2 oz of PAG refrigerant oil and install the drier. Screw on your conversion fittings and you're ready to pull a vacuum and check for leaks.

How much would a shop charge? You'll have to check around and find out. A good shop will do the following:

Remove the flexible refigerant lines.
Flush the hard lines, condenser and evaporator to remove ALL traces of mineral oil.
Rebuild/replace the flexible lines with teflon-lined 'barrier hose'.
Replace the accumulator/drier.
Remove and drain the compressor.
Reassemble all this stuff with new o-rings, add the correct amount of R134a-compatible oil, pull a vacuum and then leak-check and recharge.

This procedure involves a lot of work and chemicals. It won't be cheap. Any short-cuts show up a few months later as decreased cooling, or a couple of years later as a crapped-out compressor.

This summer, I'll be rebuilding the A/C system on a 1985 F250. I'll be recharging with R12, at a cost of $23/can. It'll take 4 cans. I'm willing to spend $100 on refrigerant for the following reasons:

1. R12 is a much more efficient refrigerant than R134. To equal the cooling ability of R12, using R134, I would need to install a larger condenser and (if I could find it) a larger evaporator.

2. Using R12, I won't need to worry about my A/C 'going away' while I sit idling in traffic on hot 'n humid east Texas summer days.

3. The cost to do a thorough (and long-lasting) conversion will easily cost as much as the R12 refrigerant. And after all that, I'll have a system that doesn't cool as well as what I had to start with.

My .02 worth of opinion.