My truck is a 1992 D250 Club Cab LE Diesel--My service manual says that my truck is equipped with service valves so to service the A C. But, have not found them as yet. Also want to change it over to 134. Can someone shed some light on this for me?? I live in Florida and it is hot, time to get this thing going.

Thanks Up Front

Will
living in sunny downtown Bartow, Fl.

 

Is there a blue plastic cap on one of the lines going into the firewall on the passenger side under the hood?

 

134a "conversion" kits are readily available, but in hot country like Florida you'd be better off on R-12 or one of the alternatives like Freeze 12.

The ports look like large tire valve caps sticking out of the A/C lines.

My truck was "converted" to 134 when I got it and it works just barely OK here in central PA.

 

There is a port with a Schrader valve in it near the firewall, (Blue cap has been replaced with a brass)and another port (black cap)on the smaller line going to the compressor. I tried to add 134 to the port closer to the firewall but it would not take it using a 134 adapter supplied with a quick service kit I got from Wal-Mart. Looking at the service manual, it says my truck has the service valves like the older Chryler/Jeep York style compressor which you have to manually open the service valve with a wrench. That is why I am confused!! I pressed the stem on the Schrader valve next to the firewall and it has pressure......... Now what?????????????

Thanks Up Front for the helps guys

Will

 

"some" pressure isn't enough to trip the pressure switch and run the compressor. If it's still on R12 you should get it vacummed down before you switch anyway.

You must have got the wrong adapter. Does the adapter have a blue cap?

 

I will look again, but, what I see is 2 adapters with black caps came with that kit. Maybe I need a certain adapter that I do not have??? I have tried to put the adapter on the port closest to the firewall and charge the system with one can from there without success. won't take it with the adapter I have.

You are certainly right about having a vacumn drawn on it. I just wanted to try and get one can in so I could check for leaks. It has just leaked down over time.

Thanks Up Front

Will

 

Thinking of that 134a suggestion, I just ask a friend of mine if he had any R12. His reply was he hasn't seen any in a long time. I will ask around about Freeze 12

Thank You

Will

 

If its R12 the 134 A from Wal-Mart wont connect. R12 uses a threaded connected where 134a doesn't.

 

I did purchase a kit from Wal-Mart that has different conversion adapters, but maybe I have used the wrong one or I am not using the correct service port. Can you advise me on which port to use?? I will go to Napa and see what they have as an adapter for my system.

Thanks for your input

Will

 

Well, here I go again. Trouble being, I put the correct fitting on the suction side and it will not accept refrigerant into the port. Seems like /acts like there is a valve that is shut off. Mind you I do not have a set of refrigerant gauges, just an input fitting and line for the refrigerant can to do a charge. Any suggestions PLEASE. as you can tell I am not a A C mechanic.

Thanks Up Front

Will

 

Listen to the voice of experience! My A/C worked fine UNTIL I changed to 134A Don't do you'll regret it. Use R12 or Freeze 12 you'll be glad you did.

 

I bought 3 cans of R12 off Craigslist last year for $15 a can. Worked great and I still have a spare! The sightglass makes it very easy.

Basically, here's what I did. I bought the R12 hose/can pierce tool off eBay for like $10, the 3 cans of R12 for $45 and a can of 'tune up' which is the oil and r12 in a small can for $5.

When you open your hood, if you stand beside the pass tire, the sight glass will be right on the top of a black canister against the fender. The low pressure valve (if memory serves me right) is right there beside it.

You pop the tool onto the can, pierce the can, hook the can up to that valve and open it up with the engine running and the AC on blast. You'll start seeing bubbles go by the little glass in the top of that canister and you just fill it up until you don't see any bubbles anymore. Mine took 2 cans. I really think it just leaked a little bit from lack of use over the last 10 years or so, so it wasn't a major chore to fill it...and here it is over a year later and it still works great.

You just don't want to use the high pressure side or bad things can happen...but I think the hose will only go on the low pressure side.

 

If you bought one of those "port adapters" it may not be screwed on far enough. I have one where I must constantly push down on it for the shrader to be held open. Some of them are kind of junky and may need a little "adjusting".

Mine is aluminum and could be easily adjusted with a file, I just haven't done it yet.

JP.

 

You cannot just put 134-a into an r-12 system, without flushing out the old oil, It is not compatible with 134-a. The seals are not either. To convert you need to flush out the system, change ALL the seals, pump it down to evacuate it, wait 20 minutes to see if it holds the vacuum and then refill it with r-134a and an appropriate oil charge. In this and most cases, I would listen to Faith, if I were you...Mark Also, there are no service valves, like on an old Tecumseh compressor, which you could shut off and replace the compressor, without losing the whole charge. My 62 Fairlane has them...I forgot to mention new filter dryer or expansion valve, whichever is used. Not doing this voids compressor warranties...

 

As a follow up: the compressors for 134-a and r12 are the same, but come with 2 different sets of seals and 2 labels to put on the compressor, you guessed it, 1 for r12 and 1 for 134-a. I have seen this on the last 2 compressors that I have replaced...Mark