A/c Charge 91 Ls

[blessed]

Hey guy's I'v got a nice 91 LS with over 200k that still looks like new and runs even better. However, it started to blow hot (or warm) air from the vents with the AC on. It tends to get a little cooler when stopped at a stop light but returns to a warm blow upon moving.

I'm guessing the AC just needs a good charge. I've owned this car for almost 10 years and had a new compressor installed about 9 years ago. If memory serves me well I have a small leak and have had it recharged once befor.

Question is...could I do this myself (and how do I do it) or do you recommend I take it to a shop?

Thanks for your input!

B

[monarch]

IF you knew what you were doing, you could recharge it in 10 minutes at a cost of about $30. But if you are a beginner, it could takes days / weeks of library / internet research to get to the point where you could do it yourself without making mistakes or hurting yourself. I'm not aware of any tutorials on the subject for Toyota / Lexus vehicles.

[ko90ls]

was your car converted from R12 to R134. This is very important to know about. look into this first. the refill procedure is very simple, just check out LExls.com and look in the A/C section. basically you run the car on MAX A/C, look near the firewall on the passenger side, unscrew the cap and fill. i suggest buying the A/C kit with a SCREW-ON CAP similar to a windex bottle and you've gotta have a Pressure Gauge included but it basically takes a 19oz bottle to fill if the A/C is empty

[alhardy]

I have 1 1990 LS400. My AC was performing just like you described. I had a 14 oz. can of R12 freon.

I would not use the hose without a guage inline. I have a guage set. I did quite a bit of research to

determine the correct PSI on the low side. I topped of my AC and stopped when the guage read 35 PSI.

It took about 7 ounces ( half a can). It is really cold now. Always fill with the can upright. You only want gas

to enter. Never turn the can upside down. It will take a few minutes to reach 35 PSI, be patient.

Note: When you connect the hose to the low side, just get the threads started, so you can open the

Guage valve to blow the air out of the line (you will hear a hiss) then quickly tighten the hose. Turn the Guage valve off then. Start the engine, set the AC on max. Turn the valve open to let the gas in. Keep an eye one the guage. Hope this helps.

[monarch]

I had a 14 oz. can of R12 freon. I would not use the hose without a guage inline. I have a guage set. I did quite a bit of research to determine the correct PSI on the low side. I topped of my AC and stopped when the guage read 35 PSI.

No gauge set is needed. You could have added R12 until the stream of bubbles in the receiver-drier sight glass dissappeared.

[blessed]

IF you knew what you were doing, you could recharge it in 10 minutes at a cost of about $30. But if you are a beginner, it could takes days / weeks of library / internet research to get to the point where you could do it yourself without making mistakes or hurting yourself. I'm not aware of any tutorials on the subject for Toyota / Lexus vehicles.

Thanks Monarch! I notice your from Sac. Ideas on where to take my 91 LS to charge the AC? What about cost?

was your car converted from R12 to R134. This is very important to know about. look into this first. the refill procedure is very simple, just check out LExls.com and look in the A/C section. basically you run the car on MAX A/C, look near the firewall on the passenger side, unscrew the cap and fill. i suggest buying the A/C kit with a SCREW-ON CAP similar to a windex bottle and you've gotta have a Pressure Gauge included but it basically takes a 19oz bottle to fill if the A/C is empty

Thanks KO.... My car has never been converted to R134 and I'm not sure if I event want to. Thanks for your input.

[ko90ls]

the only issue with conversion is that the R134 is easier to find than the discontinued R12. but i've heard you can find some on ebay

[monarch]

Thanks Monarch! I notice your from Sac. Ideas on where to take my 91 LS to charge the AC? What about cost?

No, but since your system is still blowing some cold air, then the leak is likely just a slow one and the system likely just needs a can or two of R12 which can be added in about 15 minutes. The cans cost about $20 each on Ebay and the charging hose is about $7. And for $15 you could get licensed to buy R12 by passing a 25 question on line test at www.macsw.org. An AC shop might want you to jump through a bunch or hurdles like insisiting on finding and fixing the slow leak, which in turn would necessitate labor intensive procedures like totally discharging and recharging the system, drawing a vacuum on the system, etc. In other words, a $300 - $600 repair bill. Meanwhile, don't run your AC system because compressor lubricating oil circulates with the R12 and the compressor will be somewhat starved of oil if your system is low on refrigerant R12. If you live in the Sacramento area and want me to look at your car or teach you how to recharge it, send me a private mesage.

[blessed]

Thanks Monarch! I notice your from Sac. Ideas on where to take my 91 LS to charge the AC? What about cost?

No, but since your system is still blowing some cold air, then the leak is likely just a slow one and the system likely just needs a can or two of R12 which can be added in about 15 minutes. The cans cost about $20 each on Ebay and the charging hose is about $7. And for $15 you could get licensed to buy R12 by passing a 25 question on line test at www.macsw.org. An AC shop might want you to jump through a bunch or hurdles like insisiting on finding and fixing the slow leak, which in turn would necessitate labor intensive procedures like totally discharging and recharging the system, drawing a vacuum on the system, etc. In other words, a $300 - $600 repair bill. Meanwhile, don't run your AC system because compressor lubricating oil circulates with the R12 and the compressor will be somewhat starved of oil if your system is low on refrigerant R12. If you live in the Sacramento area and want me to look at your car or teach you how to recharge it, send me a private mesage.

Thanks again Monarch....I would like to discuss your looking at my system. Not sure how to do the private massage, but I'll figure it out. Thanks for the info on turning off my AC as not to run it dry.

[Leadfoot]

I'm not aware of any tutorials on the subject for Toyota / Lexus vehicles.

Technical training course L752 has all you will ever want to know about air con, it is 9 pdf files about 3.12MB in size and can be downloaded from

http://techinfo.lexus.com

I just hope I never need it!

[blessed]

I'm not aware of any tutorials on the subject for Toyota / Lexus vehicles.

Technical training course L752 has all you will ever want to know about air con, it is 9 pdf files about 3.12MB in size and can be downloaded from

http://techinfo.lexus.com

I just hope I never need it!

Thanks! I hope I don't need it either. I set an appointment to have it charged at a shop I've used a couple of time. It's only $175 so what the heck.

Thanks again!

[Grandpa]

You guys know the price range to switch from R12 to R134?

[monarch]

You guys know the price range to switch from R12 to R134?

We discussed this in detail for you two years ago:

http://us.lexusownersclub.com/forums/index...opic=10381&st=0

[Grandpa]

rofl... and i started that topic, LOL. ANyways, the question I have is how come if you don't have any freeon, your car doesn't produce heat in the winter if the car blows heat from the engine with a fan?

[monarch]

The heater should still work in winter even if the air conditioning system is empty of refrigerant. In fact, the air conditioning system (compressor) is designed to stay shut off if the outdoor temperature is below 32 degrees F. The purpose of the engine fan is to PULL cool air from the front of the car through the radiator in order to cool the coolant inside the radiator. The engine fan has nothing to do with the heater.

[Grandpa]

The heater should still work in winter even if the air conditioning system is empty of refrigerant. In fact, the air conditioning system (compressor) is designed to stay shut off if the outdoor temperature is below 32 degrees F. The purpose of the engine fan is to PULL cool air from the front of the car through the radiator in order to cool the coolant inside the radiator. The engine fan has nothing to do with the heater.

So if my heater doesn't work in the winter, that's a clear sign of what?

[wwest]

The heater should still work in winter even if the air conditioning system is empty of refrigerant. In fact, the air conditioning system (compressor) is designed to stay shut off if the outdoor temperature is below 32 degrees F. The purpose of the engine fan is to PULL cool air from the front of the car through the radiator in order to cool the coolant inside the radiator. The engine fan has nothing to do with the heater.

So if my heater doesn't work in the winter, that's a clear sign of what?

That's a clear sign that the push/pull cable from the remix servomotor inside the A/C plenum is no longer attached to the HOT water flow control valve inside the engine compartment at the top center of the firewall. Or the valve itself is simply stuck closed.

If everything is working correctly the cable should move the valve from fully closed to fully open as you go from max cool to max heat.

[Grandpa]

Can you DIY this problem?

[lexusnutt]

Does anyone know what type of freon (R12, R134) for a '95 LS400?

Thanks in advance!

[monarch]

R134a