2500CTD

Not having much luck with info on this. I have an 85 d350 crew. Plan is a ctd conversion however, I had to replace the heater core. Would like to get the ac working. The ac didn't work but had a little in the system when I pulled the h valve off. So it appears to not have been converted from R12.

What needs to be done? I have from nothing to replacing everything. Is there a "conversion" oil that will work with both freons? Any hard parts need replacing?

patdaly

I think you are thinking of Ester oils, which work in both, but not with the mineral oil your R12 system has. I have cheated and done it without changing the oil, but only on a beater I didn't care about..

http://autoacrepairs.com/134aConversion.htm

http://teamchicago.com/Imperial/imp-ac.htm

rrgrassi

Ester oils are good, as they do not acidify with air/moisture exposure like PAG oils. Also, 134 operates with higher pressures, so make sure you use 10% less by weight/capacity. The R12 hoses are not barrier type, so 134a does tend to seep out through the hoses. It is not a very quick process though.

Also check www.ackits.com

Now would be a good time to replace the exp valve and compressor, and perform a full system flush, replacing any weakened lines. You should replace the dryer as well, even if you do not change the compressor.

j_martin

Or just button it up and charge it with C12. Available at several places or make your own, 71% propane, 29% isobutane. ( not butane)

rrgrassi

C12 huh? Where can I get that? My truck was perverted (converted) to 134a before I bought it. I do my own work. the only thing I do not have is a flush gun.

2500CTD

What about the flush gun? I have. Vac pump and a set of manifold gauges. Are new hoses barrier type. As in if I replace my ac lines, will the new ones be barrier type? Is there a way to tell by looking at them? Markings? A normal replacement evp valve would work?

My ram charger was converted but doesn't work either. Figured I will try to fix both.

j_martin

Duracool

or make your own. One 8 oz canister of IsoPro mountain stove fuel, and one 14 oz canister of Coleman propane.

Disclaimer: It looks like US EPA has gone exactly opposite the world by declaring it illegal.

I'm fascinated by the concept that 1.5 lbs of flammable gas in a tight refrigeration system is more dangerous that 400 lbs of gasoline in plastic boxes directly under the passenger compartment, inches off the road, and one between the rear axle and rear bumper. (The 15 passenger Dodge van I hauled my 9 kids around in)

There are a large number of recorded incidences of families being incinerated by gasoline from these tanks. No recorded injuries at all from leaking HC refrigerant.

93flatbed

J, not saying I would break the law or anything. But lets say I didn't live in the U.S.A. how would a fellow go about getting the fittings to go to the low side line to those two different containers you mentioned? How do you do your gas/liquid charges? Does normal R12 oil work with those?

My dealership has depleted its stock of 12 and will not order anymore. My only solution would he to buy a whole 30 pound cylinder. Not a problem for me, but if I can do it easier/cheaper I will try that first.

j_martin

Propane canister standard fitting, gate valve, and a flare fitting to fit the end of a refrigerant hose that doesn't have the shrader pin in it.

IsoPro is a bit more difficult. It has a European EN521 Lindahl valve on it, which is a poor 7/16" threaded neck with a paint spray can valve in it. I found that the collar on the MSR IsoPro canisters is slightly larger than the old freon 1 lb cans, and with a little touch up with a dremmel tool the top type can piercer adapter for freon cans will work with the IsoPro cans. It destroys the valve in the can, but it will seal and valve off the contents.

One can of IsoPro is 6.4 oz of isobutane, and 1.6 oz of propane. That and a 14 oz Coleman propane fuel canister figures out to 29/71 mix, which is perfect.

For a single evap system, you can usually just dump in a can of IsoPro, followed by the propane, and it's about the right charge. For larger (2 evap) systems I premix a batch in a re-worked 30 lb freon can. I drilled out the plastic crap and welded on a threaded collar so I can put on real valves and fittings. Just be real sure the can is well ventilated before you strike an arc on it. Phosgene is no phun.

The mix must be withdrawn as a liquid (inverted can).

Works with R12 oil.

I've heard that it is miscible with R12.

Another characteristic is that is doesn't leak as easily as R12

Please note that isobutane, and butane are different animals.
hope it helps with your off road stuff.

rrgrassi

The flush gun is for flushing solvent through the evaporator, lines, and condenser.

I use Methanol, as it removes all traces of oils, dyes and moisture. It is highly flammable, and evaporates quickly.

Do not run it through the compressor, dryer or expansion valve. You can flush the compressor with the oil you intend to use by spinning it with a drill and allowing it to pull oil through the suction side. There is a You-Tube video of it.

93flatbed

J, I'm wiping your beer debt off. If I ever make it up your way I feel I owe you a few rounds.

Thank you.

j_martin

Don't drink, but thanks just the same.

Someday I hope to float my boat in Havasu. Other relaticks in Denver. Might just loop down your way for kicks.

Jim Lane

What ever floats your boat..

As far as I understand, Dichlorodifluoromethane R-12 is still alive and well down below in out 51st state.

I know some of our members live there and I was wondering what they knew about the rumors being true.

maybe368

R-12 is still available in Mexico, but it is not cheap. You can buy it off ebay at the same price. There are many chemicals that are great refrigerants, like ammonia, but I don't see why there is such a hubbub about 134a, it works pretty good...Mark

Jim Lane

Mark,
How much is not cheap, in USD?
It is still available here from suppliers for around $1000.00 for a 30# cylinder, that is $33.3333 per pound.