Micro-Tube Parallel Flow Condenser

[maxamillion2345]

Honeslty pulling evap core and txv is easy. Have them recover all the charge and then you can pull it out. Cap the evap and wash it out with simple green and a hose and then replace txv. Its cheap and easy.

 

[Dissent]

How old is the condensor

It's all original except the compressor bearing which I replaced yesterday.

 

[Dissent]

Honeslty pulling evap core and txv is easy. Have them recover all the charge and then you can pull it out. Cap the evap and wash it out with simple green and a hose and then replace txv. Its cheap and easy.

It's still at least $100 every time I have to have the system evac/recharged. That adds up during the troubleshooting period.

 

[Dissent]

One thing I haven't read yet is PAG oil. I replaced my condenser and drier last year and added the appropriate amount amount of PAG oil directly to the condenser and pulled a vacuum. Everything worked as it should but I did notice that in high 90's plus humidity it took about 10 mins of highway speeds for the AC to get down to the mid 50's. At idle it would be able to drop to the low 60's. This year I noticed my compressor grinding upon initial start up so I bought a tool from Amazon that would allow me to add oil to a charged system. I added 60mls of PAG and now my system is blowing ICE. After sitting in the sun high 80's or low 90's and 70% humidity my AC vent temps will drop to 56-57*F at idle within 1min of startup. On the highway it drops to mid 40's. Makes sense - the oil lubes the compressor so it could spin efficiently with less drag. Worked for me anyways.

FJC 2732 Hand Turn Oil and Dye Injector Amazon.com: FJC 2732 Hand Turn Oil and Dye Injector: Automotive

View attachment 1484884

Whaaaaaaat? Seriously? What if there's too much PAG oil in the system, if I were to overfill it by accident?

 

[bloc]

Also: floor insulation. You can dramatically reduce the amount of heat radiating into the cab, which helps a given AC system lower the temps.

With 20 years of grime and dirt in the factory jute it is probably not as efficient was it once was.

 

[Dissent]

OK, here's some hard data. I went for a 20 mile drive this morning, 95% freeway. The truck was in the garage all night and morning until I left at 11:30 AM, ambient temp was 104 at the house when I left, 107 when I returned at 1:30 PM. I noticed a substantial difference in vent temp by playing with the motor speeds, assuming 1 is low and 4 is high. I did most of the tests at speed 3 which seemed the best compromise of cooling and not sweating to death. I took all temp readings using an IR thermometer on the large (suction) and small (discharge) lines on the firewall connector to the evaporator. All temps are measured in Fahrenheit.

The overarching theme is that when I have a lot of ram or high speed fan airflow (engine fan @ 2000 RPM), the temps fell. My 1 year old electric 100 series fan (Depo brand) made no difference at all on the vent temps.

Oubound Trip - 20 miles - 104 degree ambient temp
A/C vent temps ran 48 degrees all the way there. I had the blower on 4 then reduced to 2 as it was too cold.

Sitting in full sun
Truck sat in the sun for 30 minutes during my errand

Inbound Trip - 20 miles - 107 degree ambient temp
Gas stop after 2 miles of driving:
Test 1
Engine Speed - Idle (~900 RPM)
Vent Temp - 68
Blower Speed - 4
Suction Temp - 144
Discharge Temp - 164
Test 2
Engine Speed - Idle (~900 RPM)
Vent Temp - 68
Blower Speed - 4
Suction Temp - 195
Discharge Temp -197

Freeway driving moving at 75 MPH
Test 1 - 5 miles
Vent Temp - 57
Blower Speed - 4
Test 2 - 7 miles
Vent Temp - 57
Blower Speed - 4
Test 3 - 10 miles
Vent Temp - 52
Blower Speed - 2
Test 4 - 15 miles
Vent Temp - 48
Blower Speed - 2 or 3 (no difference)
Test 5 - 16 miles
Vent Temp - 55
Blower Speed - 4 (returned to 4 to validate)
Test 6 - 17 miles
Vent Temp - 53
Blower Speed - 3
Test 6 - 18 miles (off ramp stop light then driving last 2 miles at 40 MPH)
Vent Temp - 55
Blower Speed - 3

At home, parked in the street after 20 miles of driving:
Test 1
Engine Speed - Idle (~900 RPM)
Vent Temp - 55
Blower Speed - 3
Suction Temp - N/A
Discharge Temp - N/A
Test 2 - Sitting idling for 2 minutes
Engine Speed - Idle (~900 RPM)
Vent Temp - 60
Blower Speed - 3
Suction Temp - 144
Discharge Temp - 184
Test 3 - Sitting idling for 5 minutes
Engine Speed - Idle (~900 RPM)
Vent Temp - 63
Blower Speed - 3
Suction Temp - N/A
Discharge Temp - N/A
Test 4 - Sitting at 2000 RPM for 1 minute (held with hand throttle)
Engine Speed - 2000 RPM
Vent Temp - 57
Blower Speed - 3
Suction Temp - 163
Discharge Temp - 178
Test 5 - Sitting idling for 1 minute
Engine Speed - Idle (~900 RPM)
Vent Temp - 62
Blower Speed - 3
Suction Temp - N/A
Discharge Temp - N/A

 

[Dissent]

Last night, I took some temp measurements at 11:30 PM at 105 degree ambient (yeah, you read that right). I just rolled the truck out, it had been sitting for 6 hours and used the IR thermometer on the high and low side of the condenser at the connectors on either side of the condenser right behind the grill. All tests were at idle speed.
Suction Temp - 120
Discharge Temp - 150-160
Vent Temp - 60

 

[Dissent]

Also: floor insulation. You can dramatically reduce the amount of heat radiating into the cab, which helps a given AC system lower the temps.

With 20 years of grime and dirt in the factory jute it is probably not as efficient was it once was.

Granted but last year the AC performed better after Toyota did a tune up (charge). It had done a satisfactory job in the prior 3 years since I bought it. The greatest heat reducer in my opinion was replacing the steering shaft rubber seal which I did last week. Between that and the window tint on the front and sunroof glass, it helps immensely. I'm not going off of perceived heat in the truck, just line temp/pressure and vent temp. I know I can insulate more but I want to focus on the sealed AC system at this time.

 

[bloc]

Along with the steering shaft seal the shifter base gasket around the linkage can tear and let quite a bit of heat in. I know this isn't AC performance, but lots of people are reading this thread and don't think to address this heat source.

 

[bloc]

Also, being an AC expert, @TX Cruiser might have stuff to add to this thread.

 

[Dissent]

I'd start here. I think the clutch is coming in late and you have tried to compensate for that with upping the CST weight of the fluid well beyond what should work.

Our engines don't require much cooling when idling or nowhere near as much as when on the highway. So a clutch that engages late won't really effect the engine temps when idling. However the lack of air flow at idling will really impact the AC performance.

I need more 'splaining to understand what you mean by the clutch is coming in late and I compensated for it by upping the CST weight. I took the fluid weight on recommendation by @Tools R Us given his experience with OEM clutches and Phoenix heat. It would get up to 205-210 before and I've never had any issue with engine cooling since then. It sits about 195-197 all summer. The clutch sounds 100% engaged when it's hot outside and on the trail. There's no perceivable delay in when it kicks in but I'm not sure how to measure that. How is making the clutch engage more frequently bad for the AC cooling. I don't understand the relationship by pure ignorance.

What are you recommending I do with the clutch to remedy the AC cooling/airflow issues?

 

[landtank]

Our engines dont require a lot of air flow at idle to run at temperature. So if the clutch was to engage at a higher temperature (late) it would still likely not run hot.

Because you put in a high cst oil im assuming it was to combat the truck running hot while driving at speed which i'm sure it solved.

Thst heavier oil did little or nothing for the air flow during idle. Which your engine doesn't need but your AC could use.

 

[Dissent]

So, would it make idling A.C. performance worse?

 

[Dissent]

It seems this thread has turned from a "Who has this..." to an A/C Troubleshooting thread, which I do fully appreciate.

I have received a few proposals that may fix my issues prior to analyzing the temp data from this morning:

• Insufficient condenser airflow
• Sticking expansion valve
• Dirty evaporator
• Low PAG oil
• Modified fan clutch

There's a lot of different directions here, some of which may not be related to one another.

What seems most likely given the information I provided?

 

[landtank]

So, would it make idling A.C. performance worse?

No just not as good.

You need to understand that getting the clutch to engage is, for lack of a better analogy, a snow ball effect.

As the bi-metal control spring starts sensing heat it begins to rotate and allow fluid to travel within the clutch.

This begins to transmit drive, which increases air flow, which increases cooling, which increases the air temp at the spring, which causes the spring to rotate and allow more fluid to flow increasing drive.

This continues until the extra air flow doesn't result in an increase of air temperature.

In my opinion the clutch at idle isn't drawing enough air to pull the heat from the AC condenser to start the ball rolling, but does at an elevated RPM.

 

[Twinair]

Either the temperature probe is in the wrong location to read suction temp or your compressor isn't rotating. Suction temp should be beer can cold when the compressor is running. High pressure switch could be opening up, taking compressor offline. Use volt meter to confirm.

 

[Dissent]

No just not as good.

You need to understand that getting the clutch to engage is, for lack of a better analogy, a snow ball effect.

As the bi-metal control spring starts sensing heat it begins to rotate and allow fluid to travel within the clutch.

This begins to transmit drive, which increases air flow, which increases cooling, which increases the air temp at the spring, which causes the spring to rotate and allow more fluid to flow increasing drive.

This continues until the extra air flow doesn't result in an increase of air temperature.

In my opinion the clutch at idle isn't drawing enough air to pull the heat from the AC condenser to start the ball rolling, but does at an elevated RPM.

Interesting. So would a new OEM fan clutch be the answer?

 

[Dissent]

Either the temperature probe is in the wrong location to read suction temp or your compressor isn't rotating. Suction temp should be beer can cold when the compressor is running. High pressure switch could be opening up, taking compressor offline. Use volt meter to confirm.

These were read with the compressor engaged. Where should voltage be read, is this in the FSM?

 

[mudgudgeon]

Also: floor insulation. You can dramatically reduce the amount of heat radiating into the cab, which helps a given AC system lower the temps.

With 20 years of grime and dirt in the factory jute it is probably not as efficient was it once was.

Absolutely.
I added thermal insulation under my carpet and got rid of the factory stuff. I did partly for heat, partly for noise.
thoroughly insulating around the shifter hole in the trans tunnel made a huge difference to the amount of noise and heat coming into the cab

 

[mudgudgeon]

• Insufficient condenser airflow
• Sticking expansion valve
• Dirty evaporator
• Low PAG oil
• Modified fan clutch

Most of these are low dollar items to trouble shoot/address.
TX valve is probably the only one that requires the system to be opened?

You can test and adjust the temperature at which the fan hub engages. Proper function is not just about having the correct oil, or the right amount of oil in them.
I re-oiled my fan hub, I tested and tweaked it while I had it apart to get the bimetal spring to open the ports earlier (at lower temp).
It made a noticeable difference to how early the fan was fully engaged.
I damage a seal putting it together, but it worked great for two weeks until all the oil leaked out