88 Trooper air conditioning replacement questions...

[gesellman]

First of all, I work in HVAC...
Residential, and some light commercial.
This doesn't mean I know diddly squat about auto A/C...
Is there any articles on PlanetZoo, or some other site on how to change out my R-12 system, (compressor is shot anyways) to R-134? And where I could buy a new compressor and parts cheap, or as close to cheap as possible? Also, I wonder if after pulling a vacuum I could safely use the existing evap coil or would I have to flush the system or replace it too?
I want to do this the right way.
Thx

[sassee]

You shouldn't have to replace the evaporator. I have swapped 3 units from R-12 to R-134A with no problems. I did flush the systems (although there is a lot of debate as to whether that is necessary) and I replaced the receiver/drier. Last sytem i flushed (my 89 Toyota king-cab 4x4), i have a hard time getting it completely vacuumed down. had to leave the vac pump on all night for real deep vac. Also, it is my understanding that the receiver/drier must be replaced, but I'm no HVAC guy anyway (just a guy with LOTS of tools and equipment!).

I'm getting ready to convert my 89 Trooper now. It's fully charged with R-12 but there must be some contaminants in the system (probably water) since it is not getting as cold as it should. i'm going to recover the r-12 (don't want the freon police snooping around!) open the sytem, replace the accumulator/receiver/drier and the expansion valve, swap fittings and recharge with R134-a. I'm not going to flush this system. We'll see how it goes.

[gesellman]

great... Could you take some pics? If it's not too much trouble....
I'm like a 3 year old, I can learn better with picture books....
I got a friend that's going to get me the parts I need from Advance Auto, so as soon as I got the money, I will tackle it...

Thx

[sassee]

I can but the A/C is several notches down on my list. It's prob gonna be another month at least before I get to it. Got to replace rear wheel bearings and axle bearings on my wifeys Sport-Trac this weekend (for the second time!) Leave it to Ford for a crappy design! Bearings can't handle the load. This is a nagging problem in all Explorers/Sport-Tracs. Next weekend I'll be rebuilding front-end in my Trooper. Weekend after that, out of town. Hopefeully in a month I'll get around to A/C!!! Hope it doesn't get terribly hot before then.

If you can wait, I have a camera!

ernie

[SurferJoe]

great... Could you take some pics? If it's not too much trouble....
I'm like a 3 year old, I can learn better with picture books....
I got a friend that's going to get me the parts I need from Advance Auto, so as soon as I got the money, I will tackle it...

Thx

The evaporator is usually OK with a good flush and pump down to at least 28.5 in or so - but if I am doing my own, I try to hold it for 24 hours.

Since you said you're gonna change the receiver/drier, then that's a given. Refrain from adding any oil to it though as the siphon will be the first thing to send oil to the rest of the system in a giant slug and can harm things.

The condenser going from R12 to R134a is gonna be on the bad side for capacity though. The 134a units have smaller tubes and lots more surface area for what is really a band-aid for a poorer refrigerant.

But - and here's where you can really make points - is that there's a variable or surge modulated expansion valve to use that is vastly superior in any ac system, but particularly so in R134a conversions. Pro AC automotive shops will be able to help you as will a real parts house.

As far as the charge and pressures and temperatures for a good charge all boil down to one solid fact: the temperature of the compressor tells all!

After charging - and it's very easy to overcharge an R134a system - is to let the temps stabilize for about 15 minutes, ignoring the gauges and shoot the temp of the compressor, trying to average the temps all along it's case.

In a nutshell:

If you can hold onto the compressor comfortable with your bare hand, you need a little more R134a.
If it's radically too hot to handle - then it's overcharged.
If it just gives a moderately uncomfortable amount of heat to your hand - it's really close to the correct charge.

Try to get near to 160ºF or so. 180ºF is getting a little high. 200ºF+ could shorten the life of hoses and the compressor and cook the oil.

I attended a lot of classes and seminars on the "New R134a" and it's new problems and after all the smoke blew away, it was the temperature of the compressor that counts!

Gauges won't really tell you the truth and they may even mislead you causing the compressor to blow or a hose to carry away. This ain't your grandfather's freon here!

If you have to replace a hose, try to get the newer "barrier type" to keep the R134a in the system.

What didn't leak on an R12 system will with the new stuff. It's molecules are smaller, hence lesser caloric conduction and dispersion capacity too.

[gesellman]

Ok... Got the goodies today,



Compressor, drier, expansion valve.

I am buying the ester oil and 134a conversion kit tomorrow.

This project will start on Wednesday and I will try to post some pictures as the process goes...
If anyone would like to add any more suggestions, your two cents are more than welcome.

And thanks Surferjoe for your help...

[gesellman]

Ok. I am starting this project tomorrow morning.
Does anyone have the exact location of the expansion valve, I imagine it's by the evap coil, but how do I reach it without breaking anything??

I can't seem to find any info on it...
Thx

[reran]

I just saw this thread and was wondering if ya given any thought to converting to a propane (hydrocarbon) blend such as HC-12a or Duracool 12a or something along those lines? It's suppose to run cooler with less head pressure and you only use about 40% of the volume of R134a refrigerant. Also, it's less expensive than R134a and it's compatible with either R12a or R134a oil. I just flushed out my entire ac system due to a failed compressor and am going to give it a try next week. We'll see how it goes.

Leland

[gesellman]

Well, as luck would have it I twisted my ankle when stepping off the trailer. It twisted pretty good to the point I heard a snap and the pain was incredible. The doctor said rest the foot apply ice to it and come back Friday for resetting. Did not break anything and I couldnt begin to tell you what it is that he needs to reset, but it sounds painful also.



So the air conditioning will have to wait until I can put pressure on it again.

[SurferJoe]

Those bar stools are TALL, huh?

[caveman]

I have a great suggestion for your Air conditioner build....Invest about $130.00 in a thin type pusher fan for in front of the condensor. I just put one on mine, and for the first time in 12 years of owning my trooper, I have ICE cold air all the time even when idling or in traffic. It's way colder now than it was with the R12 refrigerant. And the engine runs a bit cooler to on the really hot and humid days. I wired a relay off the compressor clutch to turn the fan on so I don't have to worry about it. I'll be posting pictures of the complete install on my cardomain pages soon. And the expansion valve is inside the evaporator box under the passenger side dash. You'll need to remove the glove box, A/C lines from the engine compartment/and the fan plug to get it out, once out there is snap rings--not sure how to explain--clips that hold both halves of the evaporator box together. split the halves,and you'll see the expansion valve. Hey a little insiders tip....cap the refrigerant lines off REAL good, And clean the hell out of the fins and everything in between. Remember that mildew smell when you turn on an AC ??? NOWS your time to clean it out for good!!!!!
And install the expansion valve in the exact location as the original, I mean the Temp probe and tar wrap on the probe. VERY IMPORTANT.

[gesellman]

I have a great suggestion for your Air conditioner build....Invest about $130.00 in a thin type pusher fan for in front of the condensor. I just put one on mine, and for the first time in 12 years of owning my trooper, I have ICE cold air all the time even when idling or in traffic. It's way colder now than it was with the R12 refrigerant. And the engine runs a bit cooler to on the really hot and humid days. I wired a relay off the compressor clutch to turn the fan on so I don't have to worry about it. I'll be posting pictures of the complete install on my cardomain pages soon. And the expansion valve is inside the evaporator box under the passenger side dash. You'll need to remove the glove box, A/C lines from the engine compartment/and the fan plug to get it out, once out there is snap rings--not sure how to explain--clips that hold both halves of the evaporator box together. split the halves,and you'll see the expansion valve. Hey a little insiders tip....cap the refrigerant lines off REAL good, And clean the hell out of the fins and everything in between. Remember that mildew smell when you turn on an AC ??? NOWS your time to clean it out for good!!!!!
And install the expansion valve in the exact location as the original, I mean the Temp probe and tar wrap on the probe. VERY IMPORTANT.

The electric fan was something I was planning on getting if I didn't achieve the results I needed. My main worry was trying to figure out a relay system to make it come on with the compressor, so if you have some detailed info on how you did it I'd appreciate it.

Those bar stools are TALL, huh?

SurferJoe.... You just have no idea.... I could have swore those pesky stools were walking around by themselves that night...



On the other hand, I was monkeying with the truck this weekend and managed to change the compressor, took out the condenser and evap coil and flushed them out real good, got the filter dryer in and the expansion valve changed. Took the blower off and cleaned it too.

Now I am only missing the suction side hose. Apparently there was a massive heating of the old compressor and the suction side was literally welded to the manifold, so I had to make some unforeseen cuts.

If anyone has some A/C hoses laying around this is what I need:
http://forum.planetisuzoo.com/viewtopic.php?t=30384


Thx

[caveman]

You have the dealer installed air. Not the factory air system. You are one of the luckiest men alive here's why...I last year I spent 24 straight hours pulling my dealer air out and installing the factory unit from my parts truck(with all new critical parts of course)You will only find a few trucks around that had the dealer air as it is a generic one size fits many system. I will sell you that line for $7 plus shipping and anything else you want off the dealer system for REAL cheap!!!! . I'm only charging $7 for the hassle of cleaning it and boxing it for shipment. If you lived near Nashville and came to pick it up, I'd just give you the whole system for free. As it serves me no purpose. Let me know

[gesellman]

You have the dealer installed air. Not the factory air system. You are one of the luckiest men alive here's why...I last year I spent 24 straight hours pulling my dealer air out and installing the factory unit from my parts truck(with all new critical parts of course)You will only find a few trucks around that had the dealer air as it is a generic one size fits many system. I will sell you that line for $7 plus shipping and anything else you want off the dealer system for REAL cheap!!!! . I'm only charging $7 for the hassle of cleaning it and boxing it for shipment. If you lived near Nashville and came to pick it up, I'd just give you the whole system for free. As it serves me no purpose. Let me know

PM sent....
Maybe you can also price everything except the compressor and accumulator.
Namely, condenser, evap coil, and the rest of the hoses.

I don't know what may or may not happen once I start the system so it may be a good idea to have extra "stuff".

Thx

[gesellman]

Finally able to get the hose fixed.
Thanks jlemond for replacing that fitting for me....

Pulling a vacuum for two hours now.

Will update when I'm done charging and running system...

[SAS]

So how did the A/C rebuild go?

[justwork]

I drove the trooper 500 km in 35C and realized I'm too old not to have AC. In the spring I bought used AC lines, because I lost mine in the engine swap

Anyway, I need to convert mine over as well. I know NOTHING about AC. How do you evacuate and flush the lines? Remember, I'll need this dumbed down a bit.

[caveman]

The r134A is completely compatable with the r12 system so you don't need to flush it unless you suspect contamination. when I converted mine I noticed that I could only fit about half the amount of freon (R134A) in the system. The R12 system (yours), is smaller because R12 is more efficient. You need to find a chart that has the conversion table for charge amounts relative to humidity, outside temp, and r12 system requirements as it converts to r134A. (I just added oil and slowly charged it to about 25 to 30 psi on the low side on a 75* day. Thats when I noticed the inside air getting nice and cold. The low side pressure will vary depending on outside weather conditions.

You cant flush the compressor or the expansion valve anyway. You'll ruin them. You can however pour in flush solution into the condensor and blow it out with CLEAN compressed air. You'll be wasting your time flushing the evaporator inside the cabin because you'll have to completely remove the evapo box assembly and remove the expansion valve to flush it. Mine was clean after I went thru all that work so all I really accomplished was installing a new expansion valve.

Take my experienced advise....just flush the condensor in front of the radiator.and replace the reciever drier. Those are the two parts that get all the dirt anyways.

I'll be posting some secrets on how to make EVERY first gen troopers air really cold....even with R134A. Theres a factory flaw with the air flow for the condensor. I'm too lazy to remove the brush gaurd to get pictures of the sheet metal work I did behind the grill.

[justwork]

cool... literally