How to install A/C in a 1st Gen Pickup/4Runner (13 Viewers)

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What expansion valve did you use? Was it a brand new Denso one?

Did you insulate the TXV bulb on the expansion valve when you clipped it to the evaporator?
 
Ok I fixed my electrical issue and got my system charged and it's nice and cold.

My system is an 88 parts wise with a 99 4Runner electrical system and 3.4 compressor. I still charged it the same as my 88 with the 22RE though.

I also installed a parallel flow condenser this time and it did drop my high side pressure about 35 PSI from what I'm used to seeing when I'm charging the system.

I only put in one 12 oz can of R134A and it's blowing cold. Based on my pressures, I could probably add a bit more but I don't bother since its cold enough to cycle off occasionally. It just bumps the pressure up for no noticable gain. (To me)

Since it's over 100 and I'm in my garage I put a fan in front of my radiator.

I didn't have to spray water on my condenser to get all the refrigerant in. I just set the can on the top hose to heat it up.

I took a pic of the sight glass. If this was R12 I'd add more until it flowed clear liquid. I don't even look at it with R134. Just my personal method for what it's worth. I hope it helps.

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aztoyman said:
So your entire system is new? New evap, new expansion valve, new dryer, new condenser, compressor?

Is the thermal bulb off the expansion valve clipped on to the evap tube and wrapped with insulating tape stuff??

No plugs got left in any lines?

Correct type and amount of oil in the system?

Charge port adapters can often be a bitch to use. Some are terrible and difficult to get anything to go through or your gauges to read. I've chased my tail because of s***ty adapters back in the day when they first started converting R12 systems.
Click to expand...
So I got it pumped down and started disassembly. The low pressure side valve stem was bent so that was definitely not helping the situation. In hindsight, I think that was getting cocked to the side a bit and not letting refrigerant flow as expected. Just a hunch though.
 
I had such a hard time trying to charge through adapters on one of our trucks that I took them off and charged through the original R12 ports. I just swapped the center fitting on my gauge manifold and used a 134 hose to attach to the tank/can.
 
aztoyman said:
When you say, "Turning the high side gauge on." throws me off. With a typical set of A/C gauges, they should read pressure even with the individual valves turned off. The valve is to open it to the charging hose. Sorry if I'm misunderstanding.

Where was it frosting up?
Click to expand...

I turned off the refrigerant can side valve at the can, low side off and high side on to see that pressure while running. IF, the gauge should show low and high while turned off then my prognosis that the high/low cores were installed wrong would be one of my issues. Of all the instructions I read none said to remove the original cores from the low/high connections before installing the new adapters. Live and learn I guess.
 
aztoyman said:
I had such a hard time trying to charge through adapters on one of our trucks that I took them off and charged through the original R12 ports. I just swapped the center fitting on my gauge manifold and used a 134 hose to attach to the tank/can.
Click to expand...
I can see it being an issue. They are so finicky. I do wish someone of all the instructions I read would have outlined specifically to remove the original cores. I was going to but thought since nobody mentioned it why would I do it? I did also buy the new condenser. I originally wanted to keep the double row original one but to eliminate that being an issue I ordered the replacement. The Denso isn't available so I went with what is available.
 
aztoyman said:
I have had some adapters that you leave the old Schrader's in and others that you take out. I learned the hard way as well.
Click to expand...
I removed the cores and it all makes more sense now. They were so wobbly getting one wobbly core to mate to another wobbly core didn't help my situation. I can't tell if my adapters are seating into the oring so going to add teflon to the threads to make sure I have a nice seal.
 
I decided to experiment with a little more refrigerant since I have another can in my toolbox.

Sorry I don't have more concrete data. I don't have a scale to use and I can't find my pocket thermometer.

I added a "shot" that was just enough to raise the low side to 30 and the high side is steady at 200.

It feels colder for sure. The hose end that attaches to the evaporator is colder and sweating. I can see the needle on the low side gauge sweeping up and down a few PSI. The expansion is metering the flow.

I'm going to leave it here. If I had to guess at the charge volume, I'd say 14-16 oz. The second 12 oz can still feels pretty full.

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aztoyman said:
I decided to experiment with a little more refrigerant since I have another can in my toolbox.

Sorry I don't have more concrete data. I don't have a scale to use and I can't find my pocket thermometer.

I added a "shot" that was just enough to raise the low side to 30 and the high side is steady at 200.

It feels colder for sure. The hose end that attaches to the evaporator is colder and sweating. I can see the needle on the low side gauge sweeping up and down a few PSI. The expansion is metering the flow.

I'm going to leave it here. If I had to guess at the charge volume, I'd say 14-16 oz. The second 12 oz can still feels pretty full.

View attachment 3690832
Click to expand...
Jealous of your numbers. Hoping for similar next week.
 
aztoyman said:
I decided to experiment with a little more refrigerant since I have another can in my toolbox.

Sorry I don't have more concrete data. I don't have a scale to use and I can't find my pocket thermometer.

I added a "shot" that was just enough to raise the low side to 30 and the high side is steady at 200.

It feels colder for sure. The hose end that attaches to the evaporator is colder and sweating. I can see the needle on the low side gauge sweeping up and down a few PSI. The expansion is metering the flow.

I'm going to leave it here. If I had to guess at the charge volume, I'd say 14-16 oz. The second 12 oz can still feels pretty full.

View attachment 3690832
Click to expand...
Can you take a photo of your compressor? Specifically your hookups? Just saw this post elsewhere https://www.toyota-4runner.org/classic-t4rs/68641-ac-conversion.html


Their connection look backwards to what I have seen others install as for the high and low sides. If this is correct I feel very stupid. Please confirm.

DSC00504.jpg
 
The larger diameter hose going to the evaporator is the low side. The high side is usually smaller diameter and goes forward to your condenser.

My 3.4 compressor does not have any charge ports so I had to have them in the hoses.
 
aztoyman said:
I decided to experiment with a little more refrigerant since I have another can in my toolbox.

Sorry I don't have more concrete data. I don't have a scale to use and I can't find my pocket thermometer.

I added a "shot" that was just enough to raise the low side to 30 and the high side is steady at 200.

It feels colder for sure. The hose end that attaches to the evaporator is colder and sweating. I can see the needle on the low side gauge sweeping up and down a few PSI. The expansion is metering the flow.

I'm going to leave it here. If I had to guess at the charge volume, I'd say 14-16 oz. The second 12 oz can still feels pretty full.

View attachment 3690832
Click to expand...
Was this with engine and ac running?
 
@braddamarlon , yes. I had it running to charge it. I add the charge a little at a time and let things stabilize. I don't just dump in what I expect the charge to be. My truck is not factory. It's been converted to 134, has a 3.4 swap, a parallel flow condenser and different length hoses. I charge to the point that it cools well and make sure the pressures are in acceptable ranges.
 
aztoyman said:
@braddamarlon , yes. I had it running to charge it. I add the charge a little at a time and let things stabilize. I don't just dump in what I expect the charge to be. My truck is not factory. It's been converted to 134, has a 3.4 swap, a parallel flow condenser and different length hoses. I charge to the point that it cools well and make sure the pressures are in acceptable ranges.
Click to expand...
Ok gonna work on my ac this weekend. 1st I gotta mess with the compressor not always kicking on below 1k rpm. Will kick on once I give it gas. Hopefully messing with the amplifier works. I will also check to see where the psi is at for both high and low .

Once I mess with the amplifier do you think I will need to adjust the intake valve
 
Back in the R-12 days, on a factory stock truck you could just charge to spec or even get away with charging until the sight glass ran clear. That is not the case in a non stock situation. Especially with R134 A.

Even the charge to 80 percent of R12 is just a guideline.
 
If it comes on when you give it gas, the amplifier adjustment "should" take care of that.

Once you have it working at idle, the knob on the idle up valve will set your idle speed "when the A/C is on". It shouldn't affect idle with the A/C off.

It just compensates for the load at idle only.
 
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