Red Tek

[DMC-81]

Just in case you want to compare with R-12, I just checked my vent temperatures in this hot humid Florida summer with completely original (refurbed) equipment, and I recorded 58 degrees with an ambient temperature of 92+, and 45 degrees with an ambient temperature of 85 degrees.
Picture was taken on 08/13:


I also heard about good temperatures from RedTek. Has somebody recorded vent temperatures recently that they could share?

[Ron]

Has somebody recorded vent temperatures recently that they could share?

Steve Rice was getting 42 @ 90 ambient.

[DMC-81]

Steve Rice was getting 42 @ 90 ambient.

That's pretty good!! Thanks for the link.

Although to compare apples to apples, my temps were recorded on Max (recirculate) mode, fan speed 2 or 3, and driving around town with a max speed of 45 mph. I'll try to get on a toll road this week and record temps in similar circumstances.

I also found that you get lower temps on lower fan speed settings... makes logical sense.

[Spittybug]

I just put on my gauges:
Ambient temp ~88*
With A/C off: Lo 45psi, Hi 55psi
With A/C on, it keeps cycling every 4 seconds: Lo 15-37, Hi 70-140 (ish)
Air vent temp sits a hair above ambient. No pipes around accumulator are cool to touch.
My Hi side schrader valve bubbles gently with soapy water. I think I last recharged this system 2-3 years ago, so it can't be a big leak.

All this makes my fan fail light flash (Bitsyncmaster's mod) even though both fans are running nicely (Toby fans). I suspect this is voltage fluctuations. I will see if I can adjust the sensitivity. When A/C is off, after about 30 seconds the fan fail stops flashing and all is good.

IIRC, I can just add RedTek without evacuating existing R12. I can try tightening the schrader with the correct tool and then do as David suggested and get an o-ringed metal cap for it. To replace it would discharge system....

Ron, you expressed concern about introducing liquid into the low side port of the compressor. I concur, but isn't that the SOP even if filling with r12? What's the alternative, just letting it gas (I've heard of putting can in hot water) or going through a long fill hose?

It looks like I'll have to get the RedTek kit with their fill hose/gauge. It needs the can piercing valve/fitting and the other end has to fit the r12 port on our compressor.

[DMC1890]

The way I read the Red Tek info is that you can mix with the remaining R12, but that it would be best to remove the R12. Then it seems unclear as to whether it would be best to pull a vacuum on the system. One bit said don't charge into the vacuum - which sounds silly. What are you supposed to do then - suck atmospheric air back into the system first?

When are you doing this? I'm anxiously waiting to hear your results. I actually got 1890 to go around the block a couple of times yesterday afternoon for the first time in a long time, but as you know it was hot. I probably won't try the Red Tek myself until I replace the tires, which are old enough to vote.

[David T]

I don't know about this stuff. I just went on the website and read a lot of conflicting info. It says it isn't an HC then it says it is classified as one. Says it has the characteristics of Propane and Butane but isn't. Says it is a"blended" refrigerant. Says to add to an R-12 system then says don't mix refrigerants. Says not to add to a hard vacuum but how do you do that if you pull the R-12 out and don't want to mix refrigerants? Says it has a lower density than R-12 yet claims better performance than R-12. That doesn't make any sense if you know anything about thermodynamics. There is no info about "topping off" but if it is a blended refrigerant you can only "top off" once or twice at most. There are a lot of R-12 substitutes that claim to be "drop in". I have yet to see any that are as good as R-12. I am skeptical of their claims until proven otherwise. As long as you can still get R-12 why would you mess around with this stuff?

[Bitsyncmaster]

Propane (R290) is going to take over as a refrigerant because of all the EPA restrictions on everything. Your even allowed to vent to the air propane from a system. Propane was used in early years and only stopped because the new refrigerants were not flammable. There is a 150 gram limit on charge now which is why big systems don't all use it now.

[Ron]

To replace it would discharge system....

Not if you use one of these:
SchraderTool.jpg
(Search for a less expensive model)

Ron, you expressed concern about introducing liquid into the low side port of the compressor. I concur, but isn't that the SOP even if filling with r12? What's the alternative, just letting it gas (I've heard of putting can in hot water) or going through a long fill hose?

SOP is gas for a D/R12 (upright), through a manifold. Unlike when using a small "can", the refrigerant has time to expand while it travels through hose>manifold>gauge>hose.
If you must use liquid, as I said above, you could charge it at the accumulator, via the low pressure switch port if necessary. Hopefully someone hasn't removed the valve there -- Be careful. This is where I would charge any blend calling for liquid from a jug (to ensure it actually gets a blend,which is why they call for liquid...). The import things here are to not let liquid into the compressor and let the correct blend out of the container.

Hot water is sometimes used to raise the can temp/pressure, which helps speed up the charging process (gas/liquid). (Cold/impatient;-)

It looks like I'll have to get the RedTek kit with their fill hose/gauge. It needs the can piercing valve/fitting and the other end has to fit the r12 port on our compressor.

Better to connect the adapter to the center tap of the manifold.... Works for all of the above, not to mention you can watch the pressures easier.

[David T]

Cheaper tools won't have that valve that allows you to withdraw the core, close the valve undo the tool, R & R the core, and then put the core back in. You are correct, to fill using a blended refrigerant you are supposed to fill it with liquid so you don't "unblend" or separate the components. If you try filling with the gas some of the parts of the blend will vaporize at lower temps and pressures so you won't get the right mixture into the system. I like to pull a hard vacuum and get as much liquid in as I can without running the compressor. I finish off by putting in the little bit necessary by liquid slowly so I don't feed raw liquid into the compressor. When you fill with liquid the can doesn't get cold. It is only when you try filling with the gas that the can will get very cold because you are vaporizing the liquid in the can and that cools the remaining liquid which is why you would use hot water to keep the can warm. Since you are only putting in 2.2 lbs you should be able to get most of it in as liquid without even running the compressor. As for how to hook up, SOP is to hook up the blue low pressure hose to the suction port at the compressor, the red, high pressure hose to the discharge port of the compressor (it SHOULD be at the discharge of the condenser coil but there is no service port there) the yellow hose to the charging cylinder or can, and if you have a 4 handed manifold, the black hose to the vacuum pump. Otherwise you must move the yellow hose from the vacuum pump to the can. The method can vary if you have a recycler. For everyone changing the refrigerant, you are supposed to put a label conspicuously showing the type of refrigerant and the amount. Depending on what you put in you must also put adapters on so you can't easily mix up different refrigerants. Mixing refrigerants is VERY BAD. It makes what you have in your system unrecoverable and unrecyclable. When doing a major service the amount of oil in the compressor should be checked and added to if necessary. On a leaky system you can lose a lot of oil because no one ever adds any, they just shoot some gas in. Oil leaks out along with the gas. Over time you can become very low on oil. Without enough oil the compressor will not live long.

[hippieman9]

I have Red Tek In my Delorean, and it is Ice Cold. The PO had it converted by DMC CA 5 or so years ago. I had to recharge it this summer, (it had been 5 years since it was serviced last) But it works great! Bought the kit on Amazon.