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Topic: A/C system (Read 11202 times) previous topic - next topic

A/C system

Reply #15 –
Quote from: TOM Renzo;415511
Seek the system freezes the condensed moisture on the OUTSIDE OF THE EVAPORATOR surface. That is why the system drops out at 32 Lbs or app 35 lbs low side. That equates to app 35* across the evaporator so it does not freeze. A quick look at a properly working unit will have water coming out of the condensate tube. That is what you are concerned with when evap temps and clutch drop outs. The reason the clutch drops out is so the EVAPORATOR does not freeze up. It has nothing to do with the moisture in the system. Thanks

I understand this. If you read my post again ( I may have written it poorly), freezing temperatures can cause damage INSIDE the system (along with other inadequate cooling) if there is too much moisture IN the lines. The restrictor/orifice will clog with ice. What a properly charged system with low refrigerant will do is freeze the EVAPORATOR. Improper vacuum and foreign contaminants can/will damage the A/C SYSTEM. Freezing temperatures will make the evaporator's fins freeze, but not the A/C SYSTEM.

He asked about the compressor freezing up. This won't happen. A blocked restrictor/orifice can cause the compressor to push against a blockage though, which CAN damage it, but it isn't related to the compressor getting too cold.

Anyway, a cold system won't damage the compressor, and unless you've changed the low pressure cutoff, the system will stay a few degrees above freezing, all around. There isn't really anything you can do to make it not work as hard. It'll do what it does, and it does it well. As long as the thing was oiled (or preoiled) when first installed, it'll last for a  long long.
1988 Thunderbird Sport

A/C system

Reply #16 –
Well we are not seeing eye to eye as the receiver drier takes care of moisture in the system and in 99.9% of the time prevents orifice tube icing and blockage .And a pump down of no less than 6 Hours is what i always do. And also the type of vacuum pump and how efficient it is there should be no internal moisture in the system .  Well lets call it a day Thanks

ROBIN AIR TROUBLE SHOOTING MANUAL!!
If the system uses an orifice tube, there will be an accumulator between the evaporator and the compressor. An orifice tube sometimes lets too much refrigerant into the evaporator and it doesn't all boil. Since the compressor cannot compress liquid, only gas, the accumulator traps any excess liquid before it can get into the compressor. This also removes moisture that can block the tube. Dropping the clutch is how it controls freeze up. To low a charge or a CCOT switch set to low will cause evaporator freeze up.

86 the only moving parts in the CCOT system is the COMPRESSOR. If it works and the gauge readings are ok and the compressor does not make any noise your are ok. If it freezes up something is not set correctly or the system is LOW and or the CCOT switch is set to low or bypassed. Thanks
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

A/C system

Reply #17 –
Quote from: TOM Renzo;415549
Well we are not seeing eye to eye as the receiver drier takes care of moisture in the system and in 99.9% of the time prevents orifice tube icing and blockage .And a pump down of no less than 6 Hours is what i always do. And also the type of vacuum pump and how efficient it is there should be no internal moisture in the system .  Well lets call it a day Thanks

No disagreement here. Also, you shouldn't have to pull vacuum for long if you use a strong vacuum pump. Mine pulls down to 30 microns in ~5 minutes but I run it for an hour to get it down to 20 microns according to a micron gauge. Of course I don't have a ton of hours on this thing so it seals like new. I think anything below 500 microns is perfect for an A/C system, although you can get away with more. 20 microns is over 99.99% vacuum. 500 microns is closer to 99.9% vacuum. The accumulator handles the rest.

I do wish I had more use for that vacuum pump as it was spendy for the one time I used it. I use a noisy oilless one for other jobs, to keep my good one for specific jobs like A/C. So far it has only been A/C as nothing else needs the extreme vacuum. I worry for the lubrication and seals just sitting boxed up on a shelf.
1988 Thunderbird Sport

A/C system

Reply #18 –
We have a reclaimer combination system. I need this by law as the Clean air COPS might just pay us a VISIT. They did years back and we were GOLDEN!!!
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

A/C system

Reply #19 –
Quote from: TOM Renzo;415572
We have a reclaimer combination system. I need this by law as the Clean air COPS might just pay us a VISIT. They did years back and we were GOLDEN!!!

Yeah, when I made some changes to my system years ago, I just went down to a shop and had them reclaim the refrigerant for free, then charged back up at home. About as good as I can get without one of the all in one machines. I don't think those machines typically come with a micron gauge? That's the most accurate way of knowing true vacuum and how much moisture and some contamination is left in the system. Hours of pulling vacuum seems like excessive wear for the machine if it's in great shape, but whatever works is all that's needed.
1988 Thunderbird Sport

A/C system

Reply #20 –
Years back i went on the roof of the shop and put back some covers that were loose on the AC shop system. The next day the Clean air cops came in with summons books and a load of pens. Someone dropped a dime on me and said we were venting freon. All checked out and the black suite feds took a hike. They had the typical white socks and brown shoes. Come to find out a local neighbor hates hot cars and blew the whistle on us. Thank God he moved to another town. Thanks
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

A/C system

Reply #21 –
What are we talking about now?:toilet:

A/C system

Reply #22 –
Quote from: 86cougar;415756
What are we talking about now?:toilet:

Magic
1988 Thunderbird Sport

A/C system

Reply #23 –
As for the stock A/C system if it ever breaks fix it back to stock. I've got R-12 in mine (I was able to find some after I replaced the O rings) and it works great. The compressor is big. It's actually bigger than the compressor in both the 2011 Focus and 2012 Mustang I've got. The system works much better than the system in the newer cars. The interior of the Thunderbird gets quite a bit colder than the other cars at a faster rate. I keep the system set on 70-72*, depending on outside temps, to keep from being frozen out of the car. The only draw back I've noticed is when accelerating I can feel the load of the A/C compressor on the engine. I've not noticed that with the newer cars, which have smaller compressors. The newer compressors may be more efficient but the don't give the cars the "meat locker cold" feel that the big compressor and R-12 in the Thunderbird does.
88 Thunderbird LX: 306, Edelbrock Performer heads, Comp 266HR cam, Edelbrock Performer RPM intake, bunch of other stuff.

A/C system

Reply #24 –
Quote from: seek;415793
magic

lol!

A/C system

Reply #25 –
Quote from: thunderjet302;415795
As for the stock A/C system if it ever breaks fix it back to stock. I've got R-12 in mine (I was able to find some after I replaced the O rings) and it works great. The compressor is big. It's actually bigger than the compressor in both the 2011 Focus and 2012 Mustang I've got. The system works much better than the system in the newer cars. The interior of the Thunderbird gets quite a bit colder than the other cars at a faster rate. I keep the system set on 70-72*, depending on outside temps, to keep from being frozen out of the car. The only draw back I've noticed is when accelerating I can feel the load of the A/C compressor on the engine. I've not noticed that with the newer cars, which have smaller compressors. The newer compressors may be more efficient but the don't give the cars the "meat locker cold" feel that the big compressor and R-12 in the Thunderbird does.

I had my system converted about a year ago, and it still is a meat locker in my car. That's all right with me, we do get pretty hot here during the summer. I never had any one complain about my car being too hot after a few minutes.

A/C system

Reply #26 –
seek pretty much nailed it in post 4.

An improved drop-in replacement to the stock condenser is available from Spectra. http://www.rockauto.com/catalog/x,carcode,1140220,parttype,6708
If it is truly parallel flow, it'll give you a ~30% gain in condenser performance.

You could also put in a newer compressor (something like a Sanden or Seltec), but that would require new lines and new mounts for something which won't really improve performance and will barely help your mileage. Lots of work for very minimal gain.

A/C system

Reply #27 –
Quote from: JeremyB;415830
seek pretty much nailed it in post 4.

An improved drop-in replacement to the stock condenser is available from Spectra. http://www.rockauto.com/catalog/x,carcode,1140220,parttype,6708
If it is truly parallel flow, it'll give you a ~30% gain in condenser performance.

You could also put in a newer compressor (something like a Sanden or Seltec), but that would require new lines and new mounts for something which won't really improve performance and will barely help your mileage. Lots of work for very minimal gain.

Actually, I think you both hit the nail on the head. I have seen the Sanden of sell and I was wondering about that set up. So, if I ever need to replace mine, it sounds like it would work well. Thanks!

A/C system

Reply #28 –
Just curious

The older system is designed for R12 and the replacement is RA134A. Have any of you checked a temp pressure chart???

The condenser in the car is well suited for a conversion and works absolutely perfect. The stock compressor as well is more than adequate for the car and does not need an UP GRADE.
I spend money I don't have, To build  cars I don't need, To impress people I don't know

HAVE YOU DRIVEN A FORD LATELY!!

A/C system

Reply #29 –
Quote from: TOM Renzo;415862
The condenser in the car is well suited for a conversion and works absolutely perfect.
You'll find most people disagree with you. There is a reason the SN95 condenser is quite a bit larger than the Fox (~50%). All things being equal, you need more condenser for R-134a than R-12. R-134a in our cars will perform adequately at speed with the stock condenser, but on hot days in stop and go traffic, the vent temps will creep up.