How to install A/C in a 1st Gen Pickup/4Runner (3 Viewers)

[rypajo]

Maybe the expansion valve is faulty?

Really hope not, that would suck but that is where I am leaning to right now as well. Hate that I would have to evacuate the entire system to verify that... Or is there another way?

EditL Also this pressure does not seem to drop over time when the vehicle is off.

 

[braddamarlon]

I think to replace or check it the whole system needs to be evacuated then process done again

 

[braddamarlon]

If your not getting cold air in the cabin something is obstructing it and not letting it pass ie expansion valve.

 

[rypajo]

If your not getting cold air in the cabin something is obstructing it and not letting it pass ie expansion valve.

Mentioned above I am getting some cold air and the evaporator is draining so cooling is happening. I have not gotten it to take an entire 12 oz can of r134 yet. The low side is stuck at 90psi+ on the gauge and will not come down even when the compressor runs. My guess is that means my expansion valve was DOA. Thoughts?

 

[rypajo]

I think to replace or check it the whole system needs to be evacuated then process done again

If I evacuate the system again, I don't think that alone will fix the problem. It held vacuum perfectly. Is there a straightforward way to test the expansion valve? That seems like the only item that could be failing.

 

[rypajo]

With the engine off both the high and low side are the same pressure. I take it that is telling me that the pump kicked the bucket during the filling process. Thoughts? It IS making somewhat cold air but will not take more refrigerant no matter what I try. The site glass is cloudy so I believe that means it's still not filled enough.

 

[aztoyman]

When the compressor is off (no flow) you should not have a pressure differential and 90 PSI might be acceptable SYSTEM pressure. Depends on charge volume and temperature.

90 PSI low side pressure is not normal with the compressor engaged. And probably higher than the can you're trying to charge with.

The sight glass is a good charge indicator with R12. It doesn't work well for R134A. I don't even look at mine.

I don't "THINK" I put two cans in my system. I just got my A/C hose made today and pulled a vacuum so I'll be charging it shortly (In the pool with grand kids right now) and I'll let you know how much I use.

I typically charge the system with the blower on low. It lets the evap get cooler and lowers the low side pressure. Easier to push refrigerant in. As it gets more in the system it will slow down so I fill a container with hot water and put the can in to raise the pressure in the can. Sometimes I just put it in front of the hot air coming off the radiator. If I'm still having trouble getting it to take enough refrigerant, I squirt the condenser with the hose to drop the low side pressure. This ALWAYS works for me.

 

[aztoyman]

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.

 

[rypajo]

When the compressor is off (no flow) you should not have a pressure differential and 90 PSI might be acceptable SYSTEM pressure. Depends on charge volume and temperature.

90 PSI low side pressure is not normal with the compressor engaged. And probably higher than the can you're trying to charge with.

The sight glass is a good charge indicator with R12. It doesn't work well for R134A. I don't even look at mine.

I don't "THINK" I put two cans in my system. I just got my A/C hose made today and pulled a vacuum so I'll be charging it shortly (In the pool with grand kids right now) and I'll let you know how much I use.

I typically charge the system with the blower on low. It lets the evap get cooler and lowers the low side pressure. Easier to push refrigerant in. As it gets more in the system it will slow down so I fill a container with hot water and put the can in to raise the pressure in the can. Sometimes I just put it in front of the hot air coming off the radiator. If I'm still having trouble getting it to take enough refrigerant, I squirt the condenser with the hose to drop the low side pressure. This ALWAYS works for me.

Enjoy the pool. You think you will get to it this week?

Just went out and checked. It's 85 degrees out and the air coming out of the a/c is 75 degrees. Just an FYI.

 

[aztoyman]

I should get it charged tonight. I'm trying to get stuff done before I get my shoulder replaced. Coming up soon.

 

[aztoyman]

You may know this, I'm just trying to be thorough. You can charge through both the high and low side ONLY with the system off. Typically just as the initial charge. ONLY through the low side when running.

Make sure your high side valve on your gauges isn't leaking over to the low side.

 

[rypajo]

You may know this, I'm just trying to be thorough. You can charge through both the high and low side ONLY with the system off. Typically just as the initial charge. ONLY through the low side when running.

Make sure your high side valve on your gauges isn't leaking over to the low side.

I completely disconnected the high side to verify that wasn't happening.

 

[aztoyman]

Gotcha, I thought you said you were leaning so I have no idea what your experience is. I don't mean to come off as condescending. You've put a lot of effort in and you're not too shy to ask so I'm just trying to help you get some cold air.

 

[rypajo]

Gotcha, I thought you said you were leaning so I have no idea what your experience is. I don't mean to come off as condescending. You've put a lot of effort in and you're not too shy to ask so I'm just trying to help you get some cold air.

I appreciate it all. I have a decent grasp of what it to be done here but I'm stumped at this point. I'm thinking I'm going to have to go get the system recovered and pump down again and start over, preferably with a different gauge set OR I hit it with liquid by accident when I first went to add refrigerant on the low side and I blew the compressor up and will have to clean out the system and really start over. The pump seems fine as far as sound goes but for the life of me I can't figure out why it is reading the way it is on the gauges or why it won't take more refrigerant.

 

[aztoyman]

Hopefully it's something simple. It would suck to have to buy more expensive parts and clean the trash out of the system.

 

[aztoyman]

I evacuated the system this afternoon and it's holding. I grabbed a 12 oz can of R134 and opened the valve to charge the system. Just for reference, it's 102 degrees in my garage and the refrigerant has been in the garage. Just opening the valve I can pressurize the system to 30 PSI.

Unfortunately, I have some of my own troubleshooting to do. I have no power to the clutch. I'll be digging out my 99 4Runner factory manual. Hopefully I just missed a connection. It was working great before.

Sorry I will get back to you about how much I charge ASAP.

 

[braddamarlon]

What should the psi on low side be and hi side?

 

[aztoyman]

There's a pressure/temperature relationship so it really depends.

Saying that, in the 100 degree temps where I live I typically see 25-30 PSI low side and 200-225 when I'm charging. Of course this changes as cab temp changes and when driving down the road. That's just ballpark numbers for my truck in my climate.

I'm anxious to see if I get lower high side pressure with the parallel flow condenser I installed.

 

[rypajo]

There's a pressure/temperature relationship so it really depends.

Saying that, in the 100 degree temps where I live I typically see 25-30 PSI low side and 200-225 when I'm charging. Of course this changes as cab temp changes and when driving down the road. That's just ballpark numbers for my truck in my climate.

I'm anxious to see if I get lower high side pressure with the parallel flow condenser I installed.

So I tinkered a bit again this AM. Low side came down to 30ish when I started. Setting the fan to low I got the line to frost over so that was at least a good sign. It's taking a tiny bit of refrigerant but not enough to be successful. Closing everything up and turning the high side gauge on it never gets above 100 psi so as of now that would tell me the compressor is shot. Please correct my logic if that isn't correct. My second guess is it's the expansion valve but I don't see why my PSI wouldn't increase on the high side if it was the expansion valve.

 

[aztoyman]

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?