R12 freon to Freeze 12

[nis350]

I've read some old posts about some of you replaced R12 with Freeze 12 awhile ago. Just wondering if it caused any problems?

Since the Freeze 12 requires 10 to 15% less than the R12, does it mean you would see bubbles in the sight glass (collector) in the front of the car even when it is full?

In the evacuation process of the R12, does it also remove the lubricant oil? Do you just add Freeze 12 after evacuating the R12?

Any issues mixing R12 and Freeze 12?

 

[Daedalus]

Evacuating always removes some oil, which needs to be measured so the right amount can be replenished prior to charging. I don't know about performance aspects, but mixing any refrigerants is a no-no. Licensed techs are risking a lot if they knowingly mix refrigerants, and doing so could complicate future work.

 

[LJSB]

Freeze 12 is actually a 80/20 blend of 142b and 134a.
If you need refrigerant I would first identify and solve the problem that caused your system to lose it's refrigerant before you start selecting replacements or alternatives. I do not recommend mixing Freeze 12 with R12(CFC-12). I believe it is illegal to introduce a different refrigerant into a system that is already charged with another.

 

[drew]

I've actually used Freeze 12 (in a vintage Ferrari no less) and it worked fine, not great, but fine. I got it down to 55 deg with no fans in a hot garage, pressures were a bit on the high side.

I can't imagine it would cause much of a problem if you mixed R-12 with Freeze...not recommended I'm sure, but I can't see it causing any additional issues than by using Freeze by itself (which is not recommended either).

I have many cans of both Freeze and R-12 at my garage...PM me if you need a recharge.

I have an mvac cert and a rig, which I got because I phreaked when they wanted to charge me $150+$60/lb for 15 minutes of work (and they tried to make me sit around for an hour too).

Drew

 

[LJSB]

I can't imagine it would cause much of a problem if you mixed R-12 with Freeze...not recommended I'm sure, but I can't see it causing any additional issues than by using Freeze by itself (which is not recommended either).
Drew

It is illegal even for a DIYer to mix these refrigerants.(See SNAP regulations on the EPA site.)
Freeze 12 was meant to be used by itself.

 

[nis350]

I've actually used Freeze 12 (in a vintage Ferrari no less) and it worked fine, not great, but fine. I got it down to 55 deg with no fans in a hot garage, pressures were a bit on the high side.

I can't imagine it would cause much of a problem if you mixed R-12 with Freeze...not recommended I'm sure, but I can't see it causing any additional issues than by using Freeze by itself (which is not recommended either).

I have many cans of both Freeze and R-12 at my garage...PM me if you need a recharge.

I have an mvac cert and a rig, which I got because I phreaked when they wanted to charge me $150+$60/lb for 15 minutes of work (and they tried to make me sit around for an hour too).

Drew

Thanks. This is actually for my other car and they replaced it with Freeze 12. It seems to work OK in a 80 degress day.

However, I still see bubbles in the sight glass and was told that is normal with the freeze 12.

 

[drew]

However, I still see bubbles in the sight glass and was told that is normal with the freeze 12.

Yes, they are correct. Freeze requires slightly less material and it operates under higher temps/pressures, I would guess that would be the reason for the bubbles.

A better indicator of an optimal install is when pressures and temperatures are within spec.

It is illegal even for a DIYer to mix these refrigerants.(See SNAP regulations on the EPA site.)

Sure, I'm assuming the discussion was academic. I do not recommend breaking the law, excepting minor acts of of civil disobedience.

Drew

 

[latzke]

If r12 is low, why not have dealership fix whatever leaks there are and do the r134a conversion?

 

[drew]

If r12 is low, why not have dealership fix whatever leaks there are and do the r134a conversion?

Freeze is supposed to closely mimic the attributes of R-12 (better cooling than R-134a) and it is inexpensive.

 

[nis350]

Hi Drew,

Thanks for the info. They said the pressure was 25 with the r12. They evacuated the r12 and refilled with freeze 12. The pressure after the refilled is 30 (sorry, I don't really know what that pressure represents).

The vent temperature with freeze 12 is about 53 to 55 degrees (outside is about 80).

Do you think that is OK?

Thanks. :wink:

 

[Hugh]

The vent temperature with freeze 12 is about 53 to 55 degrees (outside is about 80).

Do you think that is OK?

Thanks. :wink:

Assuming about 80% humidity (which weather.com pretty much confirms), your vent temp is normal.

There's a chart in the online service manual by the way.

 

[LJSB]

Hi Drew,

Thanks for the info. They said the pressure was 25 with the r12. They evacuated the r12 and refilled with freeze 12. The pressure after the refilled is 30 (sorry, I don't really know what that pressure represents).

The vent temperature with freeze 12 is about 53 to 55 degrees (outside is about 80).

Do you think that is OK?

Thanks. :wink:

No. It should be at least 10 degrees cooler.
There are many components on a NSX that contribute to optimum performance and I think if your car is properly charged one or more need attending to.
I would start with checking the fuses for your condenser fans. They are in the fuse box under the hood on the right apron. One out can raise the vent temp. by more than 10 degrees.

 

[D'Ecosse]

I would start with checking the fuses for your condenser fans. They are in the fuse box under the hood on the right apron. One out can raise the vent temp. by more than 10 degrees.

Excellent suggestion - these are notorious for failure
Quicker than pulling the fuses however is to simply feel for draw at each of the intake ports on either side of the front bumper, under the combination lights - it should be extremely obvious if they are running or not, both in noise & air-flow. Takes only a few seconds to check this way.
Then of course if one or both are not operating, then you can check the fuses.

 

[ChopsJazz]

I've been following these A/C threads recently since it's so damn hot latley, and I've decided to just go with the r134 retrofit. Don at Hilltop Auto has a great price for the upgrade, and it seems to make the most sense.

 

[zahntech]

I've been following these A/C threads recently since it's so damn hot latley, and I've decided to just go with the r134 retrofit. Don at Hilltop Auto has a great price for the upgrade, and it seems to make the most sense.

Good thinkin:smile:

 

[D'Ecosse]

I've been following these A/C threads recently since it's so damn hot latley, and I've decided to just go with the r134 retrofit. Don at Hilltop Auto has a great price for the upgrade, and it seems to make the most sense.

If you are having a problem, Ken, converting to R134a will not solve it by itself (well, maybe temporarily). It would be important to identify what the issue is - typically perhaps a leak somewhere in the system. Just removing (what's left of) the R12 and refilling with R134a is just a short term solution to band-aid whatever your real issue is.
R12 generally performs better but is of course extremely expensive. If there is no problem, it doesn't make any sense to convert just for the sake of it. However if replacing a compressor or something, defiinitely worthy of consideration at that point.

If your system isn't as cold as it should be I would start by taking it to an AC specialist to identify the problem before considering the switch to R134A, even if that is ultimately part of the plan you finally implement.
If it does involve replacing the compressor (didn't I sell you a used one about 2 years ago??) then you should take it to an NSX specialist (like Don) as it it is not a trivial swap - requires removal of front crossmember to access.

 

[ChopsJazz]

Ken, you may be right, but I think it may simply be that my car is 15 years old and has never even had a recharge.

 

[LJSB]

I have a 134a system. At 85 degrees outside temp, standing still, just starting the car and letting it run, not driving at all, it registers 32 degrees at center vent.
Once I start to drive it goes down to low 20's. If I park and idle, for more than 15 minutes, in direct sun, on blacktop,it very slowly creeps up to 31-32 again and stays there.

I got to get Larry B back. He's the closest NSX r-12 to 134a conversion I know of, and see what he gets 2 years after conversion. He says it's ice cold but I want to see the vent numbers.

There are so many places on this car with the long plumbing, dual condensers, ambient sensors, water door, air door, control unit, and on and on, to have problems that can contribute or make for poor performance.
Just look at the manual at how long the a/c section is.

You fellows that like to do stereo work should remove, examine and clean the wad of clogging lint that is probably in the front of your ambient temp sensor in the console. You can't see it unless you unscrew it, take it out, and look directly in it.
On a older car I'll bet dollars to doughnuts it's clogged and sending incorrect info to the climate control. That can make a system feel too warm in the summer and too cool in the winter.

 

[Daedalus]

I have a 134a system. At 85 degrees outside temp, standing still, just starting the car and letting it run, not driving at all, it registers 32 degrees at center vent.
Once I start to drive it goes down to low 20's. If I park and idle, for more than 15 minutes, in direct sun, on blacktop,it very slowly creeps up to 31-32 again and stays there.

I got to get Larry B back. He's the closest NSX r-12 to 134a conversion I know of, and see what he gets 2 years after conversion. He says it's ice cold but I want to see the vent numbers.

There are so many places on this car with the long plumbing, dual condensers, ambient sensors, water door, air door, control unit, and on and on, to have problems that can contribute or make for poor performance.
Just look at the manual at how long the a/c section is.

You fellows that like to do stereo work should remove, examine and clean the wad of clogging lint that is probably in the front of your ambient temp sensor in the console. You can't see it unless you unscrew it, take it out, and look directly in it.
On a older car I'll bet dollars to doughnuts it's clogged and sending incorrect info to the climate control. That can make a system feel too warm in the summer and too cool in the winter.

Even 30*F is off the charts--literally. The system is spec'ed to deliver vent temps of about 40*F at best. Under no conditions would you ever want the evaporator, which is colder than vent temps, to drop to 32*F. Condensation will begin to freeze at that temperature, blocking airflow. The evaporator temp sensor is there to prevent freezing from happening.

 

[latzke]

Under no conditions would you ever want the evaporator, which is colder than vent temps, to drop to 32*F. Condensation will begin to freeze at that temperature, blocking airflow.

If it's not the evaporator, what is it that the water condenses to, freezes on, and then later drains off of forming large puddles of water under my cars (in the middle of summer when the cars haven't seen rain or a car wash in days)?

 

[zahntech]

If it's not the evaporator, what is it that the water condenses to, freezes on, and then later drains off of forming large puddles of water under my cars (in the middle of summer when the cars haven't seen rain or a car wash in days)?

=Owned:smile:

If an evaporator is too cold than yes it can acumulate too much moisture and freeze up completly and then block all air flow, however Unless you are in a very humid clymate it is unlikely...even then the evaporator must be far below 32 deg F.


I have done many R134 conversions that have performed just as well as with R12 if not better afterwards......persons can go on and on about how R134 is not as effective as R12 on paper all they want, but in the real world it has proven it's worth.

oh and don't talk A/C with Daedalus...He knows EVERYTHING:wink:

 

[Daedalus]

=Owned:smile:

If an evaporator is too cold than yes it can acumulate too much moisture and freeze up completly and then block all air flow, however Unless you are in a very humid clymate it is unlikely...even then the evaporator must be far below 32 deg F.


I have done many R134 conversions that have performed just as well as with R12 if not better afterwards......persons can go on and on about how R134 is not as effective as R12 on paper all they want, but in the real world it has proven it's worth.

oh and don't talk A/C with Daedalus...He knows EVERYTHING:wink:

Not EVERYTHING. But I know how to read P-T charts and repair and AC manuals. The conditions for condensation and those for freezing are not the same. If there is ice building up on an evaporator then something is wrong. Obviously it could happen, as the fluid boils at -16*F. The evap temp sensor is there for feedback to let the controller know when to disengage the compressor clutch. The temp-resistance relationship of the sensor is given in the manual and ranges from 32-86*F. Care to guess why they don't characterize the sensor below 32*F?

 

[LJSB]

Just checked my 2004 MDX. 78 degrees outside, center vent got as low as 28 degrees and went between that and 32, stop and go driving,40 mph max.
System is stock, as is from new, never opened or serviced.

 

[OLDMNSX]

I

You fellows that like to do stereo work should remove, examine and clean the wad of clogging lint that is probably in the front of your ambient temp sensor in the console. You can't see it unless you unscrew it, take it out, and look directly in it.
On a older car I'll bet dollars to doughnuts it's clogged and sending incorrect info to the climate control. That can make a system feel too warm in the summer and too cool in the winter.

Just my 2 cents worth here. When I purchased my car and drove it home from Dallas I noticed a noise in the center dash that sounded like a motor out of balance. When I did my major service on it when I got home I found the "Asperator" (technichal name for the ambient temp sensor) had dirt an crud on it. This little jewel is about $220 new. I took mine apart, cleaned it, put a drop of 3 in 1 oil on the bearing surfaces and adjusted the pre-load on the bearing adjustment. The temp sensor was cleaned with alcohol (Jack doesn't work good). It runs quiet and temp sensor seems to work good. This is truely a unique design. Just go easy on the jam nut. Remember it's nut a lug nut.

I also did a complete clean of the condensor coils. You can check my pictures in the photo gallery. Check them for any obvious blockage of air flow. I would suggest to check for exhaust air in front of the front tires (in the wheel well) for a difference in flow between the left and right side. This might help you too. I also found the fender liner had a lot of excess material in the vent area where the mold left excess material. A small razor knife can be used to remove this extra. It is easier with the fender liner off of the car, but I think that it could be done with just the wheel removed and car up on a jack stand. I ended up with a palm full of tiny gravel out of each condenser coil and about the same extra plastic out of the fender liner vents. I also made some screens for each condensor out of hardware cloth, also did one for the radiator. This stuff I got at the local lumber yard. It is stiff galvanized and has about 3/16 to 1/4 openings. Not enough to cause a air flow problem, but would bounce off small rocks and any other FOD. Foreign Object Damage.
Good Luck
Brad

 

[Zennsx]

Even 30*F is off the charts--literally. The system is spec'ed to deliver vent temps of about 40*F at best. Under no conditions would you ever want the evaporator, which is colder than vent temps, to drop to 32*F. Condensation will begin to freeze at that temperature, blocking airflow. The evaporator temp sensor is there to prevent freezing from happening.

This is 100% correct. My R12 system is around 42*.