Improve your A/C pre-2003? (1 Viewer)

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Phoenix, AZ
I recently was reading through this thread and I noticed that the 1998-2002 models apparently have a more robust AC system for slow speeds due to a fan that was removed on 2003+ models.

Living in Phoenix, we get some major heat, to say the least. I've noticed that my 1998's AC can keep up to the point of being too cold in the 80's and low 90's, but once hell opens its gates and we are seeing 100-115+ degrees, no matter if I am at a stoplight or going 65 mph on the highway, the AC just cannot cool the truck down.

The fact that the AC works so well at lower temperatures indicates to me that the system is working properly (correct me if I'm wrong here). So the question becomes: What can be done to improve AC performance, especially in the 100+ degree range? Would this LCP 2003+ fan kit or a similar fan set up benefit a 1998 LC?
 
Assuming you are not low in R134. I would improve the air flow going through the condenser and its cooling capability.
  • Clean the condenser with simple green and remove any debris
  • Check fan clutch performance
  • Check the foam is still on skid plate
It could be a clogged condenser, or other issues as well.
 
Assuming you are not low in R134. I would improve the air flow going through the condenser and its cooling capability.
  • Clean the condenser with simple green and remove any debris
  • Check fan clutch performance
  • Check the foam is still on skid plate
It could be a clogged condenser, or other issues as well.
I've checked the R134 and it is at the proper pressure. I will try to clean up the condenser. I know that my clutch fan works, but how would I go about checking its performance?

What is the purpose of the foam on the skid plate? Mine is there, but I noticed that it has pretty much disintegrated last time I had it off.

If condenser was clogged would the AC be working as well as it does in the 80-90 degree weather?
 
The condenser is just like the radiator if it's clogged up with debris, or if the fins are bent then it will not work as well. The condenser is in front of the radiator right behind the grill. Because of that it's subject to rock damage. Depending on mileage and age you may have enough damage that it'd be worth replacing.
 
the foam on top of the radiator keeps the air being forced/sucked in through the grill channeled all the way through the radiator instead of escaping up and over it doing next to nothing.

main components to consider inspecting/replacing:
-condenser
-drier
-evap core
-compressor
-fan clutch (another thread someone said if it spins more than half way around with engine off its probably due for replacement)

if everything is original, it may be time for replacement on some of these. because our older trucks already have the condenser fan, it cant get much better than it is without replacing parts.

can these fan clutches' fluid be upgraded like the 80 series?
 
So the foam on the skid plate is about 2" away from the cross member due to diff drop spacers in addition to eroding old foam.

I didn't take a before picture, but I cleaned the condenser. It wasnt too bad in my opinion, but there is some bending on the fins. See picture attached.

In terms of the clutch fan, it seems fine also. I took a video of me spinning it with my hand.

IMG_20190427_180413.jpg

 
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You should hear fan clutch engagement little after (ac on and about 10 mins) starting the engine on idle with hood open.

I'd say clean the radiator and condenser fins. Apply pressurized water (city water pressure is sufficient) from the fan side to outside.

If the fan clutch has never been replaced, consider replacing it only with OEM or Aisin. Never use other brands.

I got 3 toyotas and they are made in 92, 97 and 00 and never ever touched the ac system and functions like new. I live in W. TX and we are already around 96 F.
 
Living in Phoenix, we get some major heat, to say the least. I've noticed that my 1998's AC can keep up to the point of being too cold in the 80's and low 90's, but once hell opens its gates and we are seeing 100-115+ degrees, no matter if I am at a stoplight or going 65 mph on the highway, the AC just cannot cool the truck down.

May be get the coolant temperature when the AC is not producing cold air. I wonder if the engine is overheating.

The fact that the AC works so well at lower temperatures indicates to me that the system is working properly (correct me if I'm wrong here). So the question becomes: What can be done to improve AC performance, especially in the 100+ degree range? Would this LCP 2003+ fan kit or a similar fan set up benefit a 1998 LC?

Don't you have the factory electric fan in your 1998? Electric fan will help your AC performance at low speed or idle but I think you have some other issue since your AC is not cold at freeway speed as well.
 
I've checked the R134 and it is at the proper pressure. I will try to clean up the condenser. I know that my clutch fan works, but how would I go about checking its performance?

If condenser was clogged would the AC be working as well as it does in the 80-90 degree weather?

Do you remember the high and low side pressures? What was the ambient temp when you checked?

IF your fan clutch is the original...chances are excellent it needs replacing (even if you feel some resistance when spinning it by hand).

If your condenser is clogged internally or externally it will result in diminished performance. But I'd be looking at your evaporator first, not the condenser.

If your vehicle does not have cabin filters...the evaporator can get incredibly dirty. Might work just well enough for lower heat loads (80° F-90°F ambient) but won't handle anything higher.

IF the factory condenser fan for your 98 is missing, replace it.
 
Have you checked the actual low-side pressure with real manifold gauges? You can get a perfectly workable set of gauges off Amazon for ~$35. Look for it to be 35-42 psi with the truck warmed up and the AC on full. If it's less, than you need R-134a. Right now you are just guessing....
 
May be get the coolant temperature when the AC is not producing cold air. I wonder if the engine is overheating.
I don't notice the temp gauge on the dash getting high, my entire cooling system has been replaced in the last 2000 miles except the radiator which I have a service record for its replacement some time ago by the PO. I am not so sure it would be due to the engine overheating.
Don't you have the factory electric fan in your 1998? Electric fan will help your AC performance at low speed or idle but I think you have some other issue since your AC is not cold at freeway speed as well.
I don't see an electric fan under the hood at all, just the clutch fan - unless the electric fan is between the condenser and the radiator?
Do you remember the high and low side pressures? What was the ambient temp when you checked?

IF your fan clutch is the original...chances are excellent it needs replacing (even if you feel some resistance when spinning it by hand).

If your condenser is clogged internally or externally it will result in diminished performance. But I'd be looking at your evaporator first, not the condenser.

If your vehicle does not have cabin filters...the evaporator can get incredibly dirty. Might work just well enough for lower heat loads (80° F-90°F ambient) but won't handle anything higher.

IF the factory condenser fan for your 98 is missing, replace it.
I do not recall the pressures, I checked them right when I bought it about a year ago with the intent of adding R134, but the pressures were in the proper range according to the ambient temperature of that day.

I did just clean the condenser. It really didn't have much debris on it in general, but I gave it a good wash with the hose and then ran some compressed air through it. I will have to check into the evaporator, I do not have a cabin air filter and I'd be surprised if the evaporator as even ever been cleaned/replaced.

Is this condenser fan between the radiator and condenser? I don't see it on any of the parts diagrams and I am not seeing it on the truck.

Have you checked the actual low-side pressure with real manifold gauges? You can get a perfectly workable set of gauges off Amazon for ~$35. Look for it to be 35-42 psi with the truck warmed up and the AC on full. If it's less, than you need R-134a. Right now you are just guessing....
I have not used a real manifold gauge, but I used one of the gauges attached to the R134 bottles. Are they going to read that differently?
 
Just checked the evaporator, it there definitely are some blocked/clogged areas. Is there a way to clean this without draining the system or would I just need to replace it?

Sorry for the poor photo, it was hard to get it to focus on the evaporator.

IMG_20190428_132650.jpg
 
Looks like evaporator is not clogged. When I bought mine, it didn't have a filter. I had a pile of dust right at the middle. I sprayed water from a garden hose and brushed with a tooth brush with an extended handle. You can see the dirt washing down on the drain line. I washed it and vacuum cleaned with a 90 degree bend made by cutting a kids plastic golf stick.
 
Looks like evaporator is not clogged. When I bought mine, it didn't have a filter. I had a pile of dust right at the middle. I sprayed water from a garden hose and brushed with a tooth brush with an extended handle. You can see the dirt washing down on the drain line. I washed it and vacuum cleaned with a 90 degree bend made by cutting a kids plastic golf stick.
There is a little bit built up on there, I will try your method to get it cleaned out.
 
I don't notice the temp gauge on the dash getting high, my entire cooling system has been replaced in the last 2000 miles except the radiator which I have a service record for its replacement some time ago by the PO. I am not so sure it would be due to the engine overheating.

I don't see an electric fan under the hood at all, just the clutch fan - unless the electric fan is between the condenser and the radiator?

I do not recall the pressures, I checked them right when I bought it about a year ago with the intent of adding R134, but the pressures were in the proper range according to the ambient temperature of that day.

I did just clean the condenser. It really didn't have much debris on it in general, but I gave it a good wash with the hose and then ran some compressed air through it. I will have to check into the evaporator, I do not have a cabin air filter and I'd be surprised if the evaporator as even ever been cleaned/replaced.

Is this condenser fan between the radiator and condenser? I don't see it on any of the parts diagrams and I am not seeing it on the truck.


I have not used a real manifold gauge, but I used one of the gauges attached to the R134 bottles. Are they going to read that differently?

Condenser fan (if there) is located right behind the grill and in front of the condenser, its the first thing you will see.

Very important to check both the high and low side pressures with an actual manifold gauge. Low side pressure is only half the story and observing both pressures.... you can use them as diagnostic tools for troubleshooting your system.

I.E. blockage in either the condenser or evaporator, poor compressor performance, etc....
 
Condenser fan (if there) is located right behind the grill and in front of the condenser, its the first thing you will see.

Very important to check both the high and low side pressures with an actual manifold gauge. Low side pressure is only half the story and observing both pressures.... you can use them as diagnostic tools for troubleshooting your system.

I.E. blockage in either the condenser or evaporator, poor compressor performance, etc....
In that case, no condenser fan for me. I will look into installing an electric fan there to improve slow speed airflow.

As far as diagnostic tools, I will check with a real manifold gauge.
 
I don't notice the temp gauge on the dash getting high, my entire cooling system has been replaced in the last 2000 miles except the radiator which I have a service record for its replacement some time ago by the PO. I am not so sure it would be due to the engine overheating.

I would consider fan clutch as part of cooling system, and that is not replaced, correct? A bad fan clutch could cause warmer coolant temperature or overheating. It would be nice to know the coolant temperature even your temperature gauge didn't get to HOT/HIGH. With 100+F ambient temperature, the AC performance will be different when the coolant temperature is at 192F or 225F. I don't think you will see any movement in temperature gauge when the coolant is at 192F - 225F.

I don't see an electric fan under the hood at all, just the clutch fan - unless the electric fan is between the condenser and the radiator?

Fan is in front of condenser. I saw dust print that resembles the fan assembly outline in your condenser picture. I thought may be you removed the fan to clean the condenser.
 
I do not recall the pressures, I checked them right when I bought it about a year ago with the intent of adding R134, but the pressures were in the proper range according to the ambient temperature of that day.

If you have a slow leak in your AC system, an OK system a year ago may not be so okay today.
 

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