you need to plug all the small holes in the front of the chassis, it takes time but well worth it. You also have to plug the large holes behind the seats, these contribute to cross flow problems with hot air from the front to back and also direct heat transfer from the engine compartment. try to use rubber gasket material to seal off the lower doors as well as you can, and place 5/8 inch closed cell neoprene foam under the carpet especially on the access engine panel. Insulate the AC hoses where ever you can with closed cell pipe insulation and check to make sure your ac blower is working properly, many early ones at least did not go into high position. Go to the thicker Olthoff rear window, insulate your exaust pipes. All these thing will help greatly with heat as well as noise.
Cool on a hot day
- Thread starter Jim Craik
- Start date
John, at this point with it already in the car I'm not sure how I would check that? I can pull the plug on the side but there is no way to look inside with it where it is. I don't think they come with a dipstick.
Chuck, I've already plugged all the holes and insulated just about everything in sight. Except for the big weight in the back I think the thing would float.
Chuck, I've already plugged all the holes and insulated just about everything in sight. Except for the big weight in the back I think the thing would float.
Jack Houpe
GT40s Supporter
Richard if its been in use don't mess with it in my opinion. If it hasn't been charged then put 8 oz of oil freon mix with 2.5 cans of 134 and your good to go.
Jack, I got a small can of 134a/2oz of oil and about 2/3 of a can of 134a and it didn't seem to want and take any more. What kind of high/low side pressures should I see when all is said and done. I blows cold air but I didn't measure the temp, mid to high 30's I would guess. Did you take your 40 with you to NorCal? I also vacuumed it down overnight.
Jack Houpe
GT40s Supporter
Richard I would not worry about the high side reading at this time since your system is new. If you pulled a vacuum on the system all night I would have shut it down and wait for 3-4 hours to check that you haven't any leaks. If the reading is the same and while the system is under vacuum put the small can of oil on your freon can tap and open it (puncher the can) upside down, the vacuum will suck all the oil and freon into the system, then do the same with the first can of freon but not upside down. Start the car with the ac on and blower on high. Have the engine at least 1500 rpm, the freon will slowly be transfered into the system. On your gauge which is on the low side or bigger line in your car you read pressure and just above the pressure reading on the gauge you will see temp of the evaporator. As pressure increases so does the temperature of the evaporator. You want to get the evaporator temperature in the high 30s to low 40s F at 1500-2000 rpm. Its just the opposite of what most people think about ac systems. The lower the pressure on the evaporator the lower the temp, but when the evaporator temp gets in the low 30s it will freeze over causing no air to flow through it which people think its not cooling enough, but actually its cooling to much. Freezers in our homes operate with the low side pressure at 1 psi, our ac systems in our homes operate with the low side about 68 psi with R22. These pressures are round abouts not exact as outside temp has a big influence on the gauge reading. As far as your dash temperature reading you must remember the slower the air passes through the evaporator the more time it has to extract the heat from the air. So that being said the lower speed will produce a lower temperature but its the high CFM with lower temp that cools us. On high my car vents read 44-50 F on high speed on a 95+F day here in Arkansas, as the car is moving down the road with the air recirculate switch pressed. Your temp could be slightly different as your in a drier climate.
I am not a heat air guy, I am an electronic tech but learned this while on the ocean having to service 3 central AC systems. So if my explanation is incorrect I will take the tongue lashing with open ears.
For our systems, seems like the majority of people are having great success with 2.5 cans of R134. If you read the gauge while charging this is the most accurate.
No, I sure would have like to but I brought my Renault R5 turbo2 to leave here in CA. I might be heading your direction, as I have family in Olympia WA. I would be happy to help if I can.
Jack
Jack,
Interesting... after repairing my broken hose and evacuating the system for a full day, I put one can in my car (with the oil) without running the engine.
Once I had the oil pan back on, I started it up and turned on the A/C. I had what I thought were good pressures. Low was around 40, high around 150-160. I had cool air (didn't measure the temperature) and I started putting more freon in, but all I did was increase the low to around 60psi. I stopped at half a can more because it wasn't as cool as when I started with only one can.
I'm confused... Every time I try to put more freon in, it gets worse instead of better. I replaced the compressor, drier and expansion valve. My pump showed 28 for vacuum for over 6 hours and that value held without pumping for a day, so I'm confident I don't have any leaks.
Why should I get worse performance when I try to put in the 'recommended' amount of freon?
Sigh...
Kirby
Interesting... after repairing my broken hose and evacuating the system for a full day, I put one can in my car (with the oil) without running the engine.
Once I had the oil pan back on, I started it up and turned on the A/C. I had what I thought were good pressures. Low was around 40, high around 150-160. I had cool air (didn't measure the temperature) and I started putting more freon in, but all I did was increase the low to around 60psi. I stopped at half a can more because it wasn't as cool as when I started with only one can.
I'm confused... Every time I try to put more freon in, it gets worse instead of better. I replaced the compressor, drier and expansion valve. My pump showed 28 for vacuum for over 6 hours and that value held without pumping for a day, so I'm confident I don't have any leaks.
Why should I get worse performance when I try to put in the 'recommended' amount of freon?
Sigh...
Kirby
Jack Houpe
GT40s Supporter
Mike Trusty, Mechanical engineer extraordinar has taught me a few things over the past 20 years. When he speaks, I listen sort of like that EF Hutton commercial. 
The high side is effected by outside temp and also blockage in the system or bad compressor valves, if its new I usually don't even hook the gauge to it as it really doesn't tell you much. Over charging is one of the worst things you can do it will cause excessive load on the AC compressor and also it will not cool you as much.
Glad you got that fixed for this winter. HA
The high side is effected by outside temp and also blockage in the system or bad compressor valves, if its new I usually don't even hook the gauge to it as it really doesn't tell you much. Over charging is one of the worst things you can do it will cause excessive load on the AC compressor and also it will not cool you as much.
Glad you got that fixed for this winter. HA
Well, I have the chart that shows pressures vs temperatures.
And how can 1 1/2 cans be overcharged?
Enquiring minds want to know!
:furious:
Just kidding... Winter? What winter? It is still hot around here!
although I will admit to it cooling off at night now...
Later,
Kirby
And how can 1 1/2 cans be overcharged?
Enquiring minds want to know!
:furious:
Just kidding... Winter? What winter? It is still hot around here!
although I will admit to it cooling off at night now...
Later,
Kirby
Mike Trusty, Mechanical engineer extraordinar has taught me a few things over the past 20 years. When he speaks, I listen sort of like that EF Hutton commercial.
The high side is effected by outside temp and also blockage in the system or bad compressor valves, if its new I usually don't even hook the gauge to it as it really doesn't tell you much. Over charging is one of the worst things you can do it will cause excessive load on the AC compressor and also it will not cool you as much.
Glad you got that fixed for this winter. HA
Jack Houpe
GT40s Supporter
Kirby, I don't know what your gauges are saying but if you have the needle on the low side gauge reading about 38-40 degrees on the evaporator @ 1500 rpm then 1.5 cans will do the trick. Seems a little short of 134 compared to the rest of the cars. You got me.
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