A/C System rebuild - what should I replace?

[Mattchu60]

My truck has A/C but it hasn't worked in years. When the engine was pulled last year the system was emptied (not much in it anyways) and when I reinstalled the engine, I just unplugged the compressor wiring so it wouldn't be used by accident.

Its been sitting empty for a long time. I would really like to get it working now. I believe the compressor is in good condition. What should a person condsider replacing in the system? I'm going to have the truck apart again soon so thought this was a good time to replace anything. I heard once that if they are empty some things should be replaced as air would ruin them- maybe it was the drier assembly? Any thoughts would be helpful.

Or should a person just go nuts and replace everything like the hoses, condensor, drier, evaporator all at once?

[moregrip]

Originally Posted by Mattchu60

My truck has A/C but it hasn't worked in years. When the engine was pulled last year the system was emptied (not much in it anyways) and when I reinstalled the engine, I just unplugged the compressor wiring so it wouldn't be used by accident.

Its been sitting empty for a long time. I would really like to get it working now. I believe the compressor is in good condition. What should a person condsider replacing in the system? I'm going to have the truck apart again soon so thought this was a good time to replace anything. I heard once that if they are empty some things should be replaced as air would ruin them- maybe it was the drier assembly? Any thoughts would be helpful.

Or should a person just go nuts and replace everything like the hoses, condensor, drier, evaporator all at once?

interested in this as well!!

[BamaDave]

Once I get to that point, I'm going to replace everything but the compressor and lines. Going back with R12 also.

[moregrip]

Originally Posted by BamaDave

Once I get to that point, I'm going to replace everything but the compressor and lines. Going back with R12 also.

How do you do that? lol, I'm a little AC dumb!

[Nick_R_23]

The biggest question is has your system been sealed this entire time? If so, then you'll probably be safe with a new drier and o-rings at each connection. If not, then it would be better to replace the whole system. You should be able to bring it down to a qualified A/C shop and have them do a flush and leak test to make sure none of your major parts are damaged or leaking.

[Mattchu60]

System is closed up - no open connections, but its empty of refrigerant and it was opened up with the compressor was taken off for the engine swap, so it has regular air in it right now.

I can get a new condenser, drier, and evaporator and A/C hoses from rock auto for about $250 -mostly Delco brand stuff

[Nick_R_23]

That's a good thing. Dirt is obviously not wanted in the system but moisture is really the biggest killer. Take it in while it's still together and have them do a flush/evacuation of the system to pull any of the old oil out, then replace the o-rings and drier and you should be good to go with new oil and a fresh charge.

[ApacheIvan]

Originally Posted by Nick_R_23

That's a good thing. Dirt is obviously not wanted in the system but moisture is really the biggest killer. Take it in while it's still together and have them do a flush/evacuation of the system to pull any of the old oil out, then replace the o-rings and drier and you should be good to go with new oil and a fresh charge.

What Nick said.

I just replaced everything, when I went in to have it serviced the first question they asked is if the drier had been exposed to air more than 20 minutes. If you replace anything replace that and all the seals, but make sure the drier is the last thing you do and do not pull the plugs from the joints until you are ready to install it.

[DieselSJ]

What year truck? Staying with R12 or converting to R134?

Either way, I say replace all and start fresh. By the time I finished chasing leaks, I ended up replacing everything anyway. And while you are changing the evap, change the heater core at the same time while you are in there. If you have a later truck with orifice tube then also replace it (and if converting to R134 then change it to a F*rd "blue" orifice tube). And go with a parallel flow type condenser if you are changing to R134. My A/C cools my cab so well that we actually get cold.

[Mattchu60]

Thanks for all the replies. Its already converted to 134 and I planned to continue to use 134 for it.

That raises a question - the orffice tube - they show you can the standard ones for like $1 and then they also list the automatic adjusting ones which are like $20. No idea if its worth springing for the $20 one or not.

[DieselSJ]

Originally Posted by Mattchu60

Thanks for all the replies. Its already converted to 134 and I planned to continue to use 134 for it.

That raises a question - the orffice tube - they show you can the standard ones for like $1 and then they also list the automatic adjusting ones which are like $20. No idea if its worth springing for the $20 one or not.

The adjustable suck. Just get a blue one. Application is pretty much any F product late 80's through present day. I used 2001 F150 as I used to own one.

[SCOTI]

Originally Posted by DieselSJ

The adjustable suck. Just get a blue one. Application is pretty much any F product late 80's through present day. I used 2001 F150 as I used to own one.

Curious? Why not just use the recommended unit for GM trucks?

[DieselSJ]

Originally Posted by SCOTI

Curious? Why not just use the recommended unit for GM trucks?

Because orifice size in the blue tube works best in systems converted from R12 to R134.

Go search the forums over at www.ackits.com and there are discussions about it.

[SCOTI]

Originally Posted by DieselSJ

Because orifice size in the blue tube works best in systems converted from R12 to R134.

Go search the forums over at www.ackits.com and there are discussions about it.

Hhmm.... I'll do some reading.

[ApacheIvan]

Originally Posted by SCOTI

Hhmm.... I'll do some reading.

To that point. I put all original system back except I put R134 in, I was told by the tech that the condenser I had in it (stock) was not conducive to 134, the tubes are bigger and spaced out too far, the recommended condenser for 134 is smaller tubes and closer together. My AC with all new old stock is marginal at best. I am going to evacuate the r134 and go to R12 soon.

[DieselSJ]

Originally Posted by ApacheIvan

To that point. I put all original system back except I put R134 in, I was told by the tech that the condenser I had in it (stock) was not conducive to 134, the tubes are bigger and spaced out too far, the recommended condenser for 134 is smaller tubes and closer together. My AC with all new old stock is marginal at best. I am going to evacuate the r134 and go to R12 soon.

What you want is a parallel flow style instead of a serpentine style. A couple companies make direct replacement parallel flow style condensers for our trucks.

[Mattchu60]

Any suggestions on where to find the parallel flow style condensers for our trucks? I did a google search but came up short.

[DieselSJ]

Originally Posted by Mattchu60

Any suggestions on where to find the parallel flow style condensers for our trucks? I did a google search but came up short.

http://www.ackits.com/index.php?rout...rch=CN+3642PFC

[SCOTI]

Originally Posted by DieselSJ

What you want is a parallel flow style instead of a serpentine style. A couple companies make direct replacement parallel flow style condensers for our trucks.

I checked into this when building my dually. I called a reputable aftermarket manufacturer about one in the same dimensions as my OE unit. He told me that the serpentine condenser in these trucks had enough surface area that they would get the job done. He said I could spend the extra money for a parallel unit & might (might) see 1-2° difference in vent temps.

He said he would take my money if I insisted but that he felt the need for full disclosure.

[DieselSJ]

Originally Posted by SCOTI

I checked into this when building my dually. I called a reputable aftermarket manufacturer about one in the same dimensions as my OE unit. He told me that the serpentine condenser in these trucks had enough surface area that they would get the job done. He said I could spend the extra money for a parallel unit & might (might) see 1-2° difference in vent temps.

He said he would take my money if I insisted but that he felt the need for full disclosure.

What MFG would that be?

[SCOTI]

Originally Posted by DieselSJ

What MFG would that be?

I knew after I typed that the question would be asked. I would have to go back through my notes on the project for the manufacturer. I found them through various online threads for people wanting a custom/built to spec condenser.

[DieselSJ]

Originally Posted by SCOTI

I knew after I typed that the question would be asked. I would have to go back through my notes on the project for the manufacturer. I found them through various online threads for people wanting a custom/built to spec condenser.

$113 in the link that I provided. Even less expensive through places such as RockAuto. Cheap upgrade to the 30 year old crust pieces that we all have. My stock one was fairly intact thanks to the dry desert climate but it was still 30 years old rusty and corroded. Nothing custom needed here - they are available off the shelf and ready to bolt in.

[SCOTI]

Originally Posted by DieselSJ

$113 in the link that I provided. Even less expensive through places such as RockAuto. Cheap upgrade to the 30 year old crust pieces that we all have. My stock one was fairly intact thanks to the dry desert climate but it was still 30 years old rusty and corroded. Nothing custom needed here - they are available off the shelf and ready to bolt in.

I'm aware there are direct fit units (I have one). I was researching the benefits of the largest parallel flow unit @ the time & when I reached out to the guy he told me I didn't need anything larger than what I had (thus why I just replaced my original unit w/a new part).

[tucsonjwt]

The local A/C shop recommended an AC Delco parallel flow condenser. I forget the part number but I think it will come up on a Rock Auto catalog search for your vehicle. He said the condenser will be a direct fit.

He also recommended a Sanden compressor but it would require a flimsy looking Rube Goldberg adapter bracket (like 3 separate pieces) for my 454 which I did not like, so I think I will just go will a new Alma A6 compressor. The shop owner has an 85 454 and he still has the original A6 in it but he says he just keeps replacing whatever the system needs since it is essentially "free" for him.

[El Dorado Jim]

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