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93 Truck AC Parts

dbrannon79

I'm getting there!
Messages
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Location
Seguin, TX
Today I was thinking about looking at what it would cost me to round up all the parts needed to get the AC working in my 93 since as we say it here in Texas, "Were about to step off from hell's front porch".

I put a parts list together and here is what I have so far, as to my knowledge the AC has not worked since 2009, but I did feel the compressor. it still turns by hand.

1. suction/discharge hoses (metal line has a rub through area)
2. liquid line (same issue)
3. accumulator/dryer (missing)
4. orifice tube
5. seals and o-rings
6. retrofit fitting kit (still is setup for r-12, might go with enviro-safe but still on the fence with that)
7. oil

Looking up all the parts on RA, it seems I can get most everything except for the compressor for right at $100. One thing I did notice was the listing for the receiver/dryer. they show a tapered and a flat bottom. I have no idea which one is needed or if it even makes a difference. mine is completely missing.
 
I'd also replace the condenser, unless you know it was replaced recently. I'm sending one for my '93 over to @Twisted Steel Performance for coating here shortly.

What specifically is in the retrofit kit? The compressor on my '93 is likely original and no good, so I'll be upgrading that too. From what I've seen on here there's some wiring that has to be done and some diode needs to be wired in for the high pressure cutout switch that's on the newer compressors but wasn't on the original '93.
 
The condenser looks factory but is beefier than what's on my 95. the retrofit kit is just a couple of fitting that replace the old threaded r-12 service port so the 134a quick connects on the gauge manifold will connect.
 
I was planning on just flushing everything out. hoping both the condenser and evap was clear. it's been open to the environment for several years, so I'm sure it all will need to be replaced at some point.

I also forgot about some of the 30lb bottles I acquired a while back free off the FB market place. some of the refrigerant I have not heard of before but are old. came from an old barn from what I was told. I do recall googling the numbers on the bottles and finding that one of them was a replacement for old r-12 in stationary appliances. I might look into that more and see if any can be used in the automotive applications. I will have to go back and look to see what the "r-number" was
 
but I did feel the compressor. it still turns by hand.

Just replace it now. The R4's are good for maybe one season before they leak --> run low on refrigerant --> fail to return enough oil --> debris glitter bomb the system as a courtesy --> Lock up or make noise.

Maybe in less extreme temps they make it two years.

Seriously post a picture of it. I would inspect the body O ring areas for signs of leaking oil.

R4_goes_pop.jpg
 
It's old and crusty. hasn't been in service since 2009 and as far as I know has been missing the dryer since then as well so the whole system has been open to the environment all this time. Just because I can turn the clutch by hand doesn't mean it will work LOL. I am sure the compressor is already dead if not, as soon as I attempt to charge it, it will grenade on me! I figured so long as I install those screen filters they made to save the condenser I might as well see if it will work. Unless I can scrounge up some extra cash and get a new one.

I was thinking about just piecing this one together just so it would work since this truck is at the moment just for "the mean time" while I get the 95 in tip top shape.

Here is the current compressor...

IMG_5100.jpgIMG_5099.jpg
 
It looks like that compressor has the high pressure cutout switch. As far as I know the original '93 didn't come with the high pressure switch. At least it's not there on mine and I'm certain it's stock. Would you be willing to show some photos of how the newer compressor switch was retrofitted to the stock wiring?

In my opinion you're better off waiting/ saving money for a new compressor. You're just going to waste refrigerant trying to get the old one to function only to have to replace it soon thereafter. They just don't hold up for very long whether in use or not
 
I will look again at the wiring but when I was cleaning up a lot of what the PO did I think I looked over that side of the engine looking for the connector that was MIA for the low pressure cycle switch. everything looked factory. I disco-ed the clutch and folded the connector back in case it tried to turn the compressor on. when I finally found the cycle switch connector that goes on the accumulator, to my surprise it was the small style one like what's on that high cut out switch. I was looking for the older style large connector since it was an r-12 system.

maybe this one has the high cut-out switch here since it doesn't have anything on the condenser like my 95 does. when I had the front grille off I noticed the absence of that switch along with what seemed to be the absence of the ridges in the condenser line where the orifice tube would be along with the lines coming off it were short unlike my 95 were the lower line that has the orifice is long and straight. I didn't give it much look at that time but now that I think about it when I had the inner fender off working on the turbo drain pipe I also recall not seeing where the orifice could be at near the evap under where the accumulator goes.

I might be finding what is a pieced together AC system where the wrong parts were cobbled together and was left like this after whoever was doing it figured out it wasn't gonna work without a place to put the orifice tube! if my memory serves me right, the fitting threads will go together for the liquid line from an newer truck and an older condenser that had the orifice up under the accumulator! This might turn into a real adventure having to replace everything and costing more $$ that I want to spend LOL

Might be cheaper to install a beer window and shove a window unit in with a generator HAHA... Hillbilly style 🤪
 
I scoured through my phone looking for a photo I took hoping I had one showing the lines on the condenser. this one pic was all I had. I do recall the lower line is shorter than whats on the 95. looking at this pic, this line is also not straight. I don't remember if it was but I doubt it was long enough even if it were to be bent straight to physically fit an orifice tube here, but I might be wrong. I have slept since I took the pic and I wasn't really paying much attention to the AC!

Here is what I took, it's a side view when I was wanting to see what I needed to straighten the fender. I also screenshotted it zooming in on that lower line.

IMG_4954(1).jpg
image0.png
 
I will look again at the wiring but when I was cleaning up a lot of what the PO did I think I looked over that side of the engine looking for the connector that was MIA for the low pressure cycle switch. everything looked factory. I disco-ed the clutch and folded the connector back in case it tried to turn the compressor on. when I finally found the cycle switch connector that goes on the accumulator, to my surprise it was the small style one like what's on that high cut out switch. I was looking for the older style large connector since it was an r-12 system.

maybe this one has the high cut-out switch here since it doesn't have anything on the condenser like my 95 does. when I had the front grille off I noticed the absence of that switch along with what seemed to be the absence of the ridges in the condenser line where the orifice tube would be along with the lines coming off it were short unlike my 95 were the lower line that has the orifice is long and straight. I didn't give it much look at that time but now that I think about it when I had the inner fender off working on the turbo drain pipe I also recall not seeing where the orifice could be at near the evap under where the accumulator goes.

I might be finding what is a pieced together AC system where the wrong parts were cobbled together and was left like this after whoever was doing it figured out it wasn't gonna work without a place to put the orifice tube! if my memory serves me right, the fitting threads will go together for the liquid line from an newer truck and an older condenser that had the orifice up under the accumulator! This might turn into a real adventure having to replace everything and costing more $$ that I want to spend LOL

Might be cheaper to install a beer window and shove a window unit in with a generator HAHA... Hillbilly style 🤪
We used to put a window unit in the 89 Suburban. It worked great
 
LOl I sure would look funny running down the road with a window unit hanging out from one of the back doors HAHA. I could even get fancy just having the unit strapped in the bed and run some duct (pvc pipe or something to withstand the wind) in to each window.

Honestly a little $100 5k btu unit would most likely do fine to cool the cab and I could run that off an inverter and let the alternator keep the battery charged LOL If this truck actually had a beer window in the back I would do this.
 
It's old and crusty. hasn't been in service since 2009 and as far as I know has been missing the dryer since then as well so the whole system has been open to the environment all this time. Just because I can turn the clutch by hand doesn't mean it will work LOL. I am sure the compressor is already dead if not, as soon as I attempt to charge it, it will grenade on me! I figured so long as I install those screen filters they made to save the condenser I might as well see if it will work. Unless I can scrounge up some extra cash and get a new one.

I was thinking about just piecing this one together just so it would work since this truck is at the moment just for "the mean time" while I get the 95 in tip top shape.

Here is the current compressor...

View attachment 87525View attachment 87526

The High Pressure switch is either a (most likely) retrofit to R134a or a Factory 134a system. 1993 was a weird year for that I read.

This compressor will immediately start leaking again like it has in the past. The black buildup of dirt is sticking to A/C oil that leaked out. The body orings appear to have been leaking where the black steel meets the aluminum ends. It may hold a charge 24 hours...

The condenser may be compromised, leaking/cracked, from being bent up. Good luck getting the orifice tube out as is should be on the outlet of the condenser.
 
Yeah, your right @WarWagon, I was trying to remember when they started using 134A. I had 96 stuck in my head but then I snapped as my 95 is 134A. it was introduced in late 92 and was in full use by mid 93. iirc GM was the first to use 134A since they were partnered with dupont. this truck has to be factory 134A, GM was doing goofy things then. what gave me the clue it was R12 was the old threaded service ports on the lines, but in the very beginning of 134A they hadn't quite used up all the old stock parts so some if GM vehicles got the old parts installed.

The condenser is fatter with the inner tubes being larger (old R12 design) so even if I were to possibly save this condenser, it would not cool very well simply because it won't be able to shed off the heat from 134A like the newer ones can. The compressor has a "R-12" tag on it and looking at the part number, it's a remanufactured unit as well. Total junk, the entire system will need to be replaced and updated to the newer style for it to work properly. way more than I want to spend, I was just getting my hopes up to have a working ac for this summer.

Maybe, and that's a big maybe. If I end up replacing the compressor and condenser on the 95, doing it right, I might consider saving the parts to use in this truck. The 95 will hold a charge and work fine for about 2 months until I have to add a can, the compressor leaks from the body and front housing o-ring (not the shaft seal). if it doesn't grenade before then and get tossed in the scrap bin before then.

Although if I do happen to run across a rear window that has the infamous "beer" sliding window for sale cheap on market place or in the pick a part yard, I have a spare small window unit I can use... HAHA.
 
I figured I would post an update....

Well today on my black 93 truck I did what I didn't think I could do! I have been wanting to do something with the AC on it just to see what worked and what would need to be done just to have it function. I know it all needs to be replaced and gone through but I got a stubborn hair up my rear today!!

I ended up picking up a new AC dryer, orifice tube, clutch cycle switch, some pag-100 oil, and 4 cans of 134A. started tearing things down to flush, pulled the front grille off and went at removing the old orifice tube. the line coming out of the condenser was bent in two places. I managed to tweak the lower bend straight and finessed the other bend right where the threaded fitting was. Got it all straight enough to pull the old orifice. Once I got it out I noticed right away that it was not that bad. hardly any debris on it. when I went to flush it out, I first just blew through it with a rag covering the other side. nothing but air and a little oil came out which was clean oil!!

Now keep in mind this system has been open to the environment with the dryer missing since 2009. there are photos on the forum showing this.
Next I flushed the evaporator out, then went to clean out the hoses connected to the compressor. This is when I found the show stopper... the high side hose was blown out right behind the compressor!

well in a pinch I decided to run out to the local pick a part yard and see if I could find one still in tact. To my dismay every truck I found, the hoses were all cut with a knife. I soon realized that this JY was slicing the hoses as the vehicles were coming into the yard instead of recovering the refrigerants. I was about to give up when I found myself standing over a burb in the JY that had rear air. I noticed where the hose coming off the compressor manifold going to the rear was cut but the other two for the front unit was still intact.

on a whim I thought to myself, the low side only ever sees about 150 to 175 PSI when the AC is off. and I could easily plug off this extra port on the manifold and possibly use it to see what this trucks AC will do. $25 later I was on my way home with the hose LOL

Got home and got everything cobbled up. ended up using a piece of copper tubing with one end I brazed shut clamped in to plug off that hose that was for the rear air. started vacuuming it down... it held. then I thought pressurize the system with my air compressor just to see if anything leaked before wasting any cans of 134a. I pressurized it up to about 80 psi and let it sit there a while. got a spray bottle with soap and went to town on it, but only found a small leak on the high side service port. I ended up just putting the cap on it and said it's good enough I will know if this thing will work or if it's gonna explode.

added the 8 oz bottle of pag-100 oil in the dryer, some in the hose, and some directly in the compressor while rotating the clutch by hand. closed up the system for the last time and pulled a vacuum. I finished off the night (11PM) with only charging it with about 30 oz of 134a so it's a little low yet but with the blower on high I was seeing a hair under 50 degrees on the thermometer. I let it run for a while and then put the blower on medium. came back and the temp was showing right at 40 degrees!!! The compressor is not making any noise ether.

This thing has not worked in at least 14 years, After seeing the ports on the compressor clean and not full of black chalk like they normally are along with the oil that came out of the condenser clean. I am suspecting this system was working long ago when the high side hose let go and then was never fixed.

I will check it again tomorrow and possibly give it a full charge if it holds over night, but I'm in shock it actually worked!!


IMG_5172.jpg




IMG_5173.jpg
 
Some things I learned today cobbling this AC together... I found that 93 was the last year GM used SAE standard thread fittings on the evap, dryer, and the condenser. getting a better condenser to run with 134A, (I also learned this truck was factory R-12), will be hard to find since everything 94+ all use metric threaded connections.

something I didn't mention in the post above was the suction/discharge hose I got from the JY was from a 94 burb with rear air, it's fittings are metric. the tube size is the same, only the threads on the nuts. I ended up taking the new dryer into the garage clamping it on the vice, greasing the threads and very carefully working the metric line nut on to the SAE threads of the dryer. it was this or taking the old S/D hose in to our local radiator shop and having them cut and swap out the line nut for the dryer. as for the line nut that threads onto the condenser. it threaded up just fine, I could tell the nut was the tiniest bit loose on the threads (metric on SAE) but I was able to tighten it up without any issues.

in order to update the AC system on this truck and do it right, everything including the evap would have to be replaced simply due to the fitting threads on the newer units being metric, or have some one custom make both the suction/ discharge lines and the liquid line.

When I do decide to dive into this I will have to remember this and figure out what direction would be best.
 
Well this morning I connected the gauges on the low side and it was still holding a charge. I ended up installing a universal 12" condenser fan I had in the garage and wired it to a relay with the trigger wire coming from the clutch cycle switch. I also wanted to wire in the high idle solenoid as well but I think I will wire that to a toggle switch in the dash.

buttoned everything up. fired up the truck and watched the gauge and thermometer. unfortunately I cannot connect to the high side service port due to that stupid rubber ball GM put in them that always leaks after connecting gauges. this I will replace when the system leaks down.

I ended up adding another 6 oz of 134a giving it a total of 36 oz charge. the low side stayed steady at 35 psi with the high idle solenoid on and the blower on medium high the thermometer in the dash was reading 55 degrees as it was 90 outside and very humid. I'm calling it good enough for now mainly since I don't know what the high side is doing.
 
unfortunately I cannot connect to the high side service port due to that stupid rubber ball GM put in them that always leaks after connecting gauges

I replace both the high and low side valves EVERY time I touch a system. Debris from compressor wear and/or heat damage ruin em.

Dorman, if they only make ONE good product, here it it: 902-025 A/C Port Plug. Seals off the high side with a leakproof plug cap they way it should have come from the factory. Should be available at local parts store.
 
Yup. I plan to evacuate soon and replace them. I want to replace the high side with an actual schrader instead of that crappy rubber ball valve it has. I'm still in shock it's still working LOL. if it makes it through a week or two I just might conciser converting it to the enviro-safe or something that cools like the old R-12.
 
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