Sanden compressor conversion

[terry kelley]

The AC in my 72 convertible quit working. I suspect that I have a defective hose where it connects at the fire wall. (I've seen what appears o be refrig. oil in that area)All of the hoses are original to the car as is the compressor which I think still works. I have several questions regarding converting to the Sanden compressor if I am going to replace all the hoses anyway.

So here goes:

1. Has anyone done this conversion and did you like the result?

2. Should I stay with R12 or switch to R134 and why?

3. If I stay with R12 should I go ahead and replace the dryer and possibly the condensor coil to be safe?

4. If I go with R134 what about the evaporator coil under the dash? That's a job I really do not want to undertake. It's a real bear to get to on factory AC.?

5. Is it worth replacing the original hoses

Alot of questions but a complete underhood conversion from Classic Auto Air is about $900.00. I don't mind spending the money if it is worth it. Thaks to everyone in advance.

 

[RacerX]

I'm restoring my 73 convertible drivetrain including the A/C and am pondering the same issue.

I'veresearched the bracket for the Sanden compressor and it can be obtained for about $40, I've found it at a couple locations. It will mount to the base plate after unbolting the factory York compressor.

The compressor itself is a generic Sanden compressor. Available on ebay and several other locations for about $200.

Add about $250 for replacement hoses and a newer oversize condenser to accommodate the 134 less efficient freon (about 85% of R12) and for about $500-600 I'll have a complete changeover to R134 with the new Sanden compressor (that doesn't have near the drag that the original York does!)

 

[caspianwendell]

In my experience with HVAC the york compressor and R12 cannot be beat. This is not to say that sanden is no good, they work great but the low RPM cooling is substandered with 134a. If you break the system open, this would be a good time to flush it, inspect everything, change the orifice tube filter, and vaccume it down real good before recharging. I have converted several older cars from 12 to 134 and they work fine, but to me the 134 does not cool as well as 12.

 

[Don C]

Chances are you won't be able to find any R12, unless you know of someone that has some stashed away, as it hasn't been produced for quite a few years. As noted, R134 is not as efficient as R12, so expect some loss of cooling. Depending on where you live might not be an issue, where I live you need every bit of cooling power available.

If you convert, it is a good idea to flush the system as good as possible. Make sure you get R134 that is designed for conversion, so the oil in it is compatible with the oil that was in R12. Coversion kits are readily available, and should include everything you need, including the retrofit fittings. You should have a good vacuum pump available to draw as much air out of the system that you can. Hoses used on R12 should be compatible with R134. Be cautious about retrofit kits, some can contain isobutanes and propanes (called hydrocarbon fluids in their ads), may be called R12a, are obviously very flammable, and are not SAE certified.

R134 will be phased out at sometime in the future, as it also contains ozone depleting HFC, which is not a bad as R12's CFCs. The US replacement will be R1234yf.

 

[Jeff73Mach1]

In my experience with HVAC the york compressor and R12 cannot be beat. This is not to say that sanden is no good, they work great but the low RPM cooling is substandered with 134a. If you break the system open, this would be a good time to flush it, inspect everything, change the orifice tube filter, and vaccume it down real good before recharging. I have converted several older cars from 12 to 134 and they work fine, but to me the 134 does not cool as well as 12.

In your experience were the 134a systems using a 134a designed condenser or the factory condenser meant for R 12?

While it is true that 134a is somewhat less efficient than R 12 was, when the system is properly designed and balanced, it will cool every bit as well. My 134a system will freeze you out of the car if run on full blast.

 

[caspianwendell]

In my experience with HVAC the york compressor and R12 cannot be beat. This is not to say that sanden is no good, they work great but the low RPM cooling is substandered with 134a. If you break the system open, this would be a good time to flush it, inspect everything, change the orifice tube filter, and vaccume it down real good before recharging. I have converted several older cars from 12 to 134 and they work fine, but to me the 134 does not cool as well as 12.

In your experience were the 134a systems using a 134a designed condenser or the factory condenser meant for R 12?

While it is true that 134a is somewhat less efficient than R 12 was, when the system is properly designed and balanced, it will cool every bit as well. My 134a system will freeze you out of the car if run on full blast.

I change condensor, dryer (rated to XH7), orifice tube, and compressor...flush the evaporator and (barrier)hoses while it is apart. and as stated the sanden and 134 work great, but york compressors with r12 will always be my favorite. Once in my teens I fabricated a york to a 350 chevy and a mustang underdash to my old truck, the unit would throw snow at you when the humidity was right but it would kill the engine at stop lghts...lol...(over charge)...and as I said before r12 cools better at low RPMs than 134a, not in general. I have seen shops that just change the dryer and liquid flush the system and they work great, but I would not recommend that as 134 molicules are smaller than 12. You should make sure you have barrier hoses (hose within a hose) to prevent slow discharge. I use castrol retro oil instead of pag for less moisture absorbtion...Anyway thats my 2 cents...if it's even worth that.

 

[terry kelley]

In my experience with HVAC the york compressor and R12 cannot be beat. This is not to say that sanden is no good, they work great but the low RPM cooling is substandered with 134a. If you break the system open, this would be a good time to flush it, inspect everything, change the orifice tube filter, and vaccume it down real good before recharging. I have converted several older cars from 12 to 134 and they work fine, but to me the 134 does not cool as well as 12.

In your experience were the 134a systems using a 134a designed condenser or the factory condenser meant for R 12?

While it is true that 134a is somewhat less efficient than R 12 was, when the system is properly designed and balanced, it will cool every bit as well. My 134a system will freeze you out of the car if run on full blast.

I change condensor, dryer, orifice tube, and compressor...then flush the evaporator and hoses. and as stated the sanden and 134 work great, but york compressors with r12 will always be my favorite. Once in my teens I fabricated a york to a 350 chevy and a mustang underdash to my old truck, the unit would throw snow at you when the humidity was right but it would kill the engine at stop lghts...lol...(over charge)...and as I said before r12 cools better at low RPMs than 134a, not in general

Not being an AC guy like you guys seem to be, what is the oriface tube and where is it located? I'm just a nuts and bolts guy and plan on physically swaping out out the necessary parts and let a real AC guy do the system purge etc. I'm looking for the best method to get my AC working again. I do live in Dallas,Texas so it gets real hot here. (average 106 last week) so whatever I do I want to be sure it will cool when I'm through. If doing a full change over to R134 is required I'm OK with that but if I can get by with new hoses, a system purge and recharge thats OK too. Don't they still sell R12 at just a higher cost?

 

[caspianwendell]

In your experience were the 134a systems using a 134a designed condenser or the factory condenser meant for R 12?

While it is true that 134a is somewhat less efficient than R 12 was, when the system is properly designed and balanced, it will cool every bit as well. My 134a system will freeze you out of the car if run on full blast.

I change condensor, dryer, orifice tube, and compressor...then flush the evaporator and hoses. and as stated the sanden and 134 work great, but york compressors with r12 will always be my favorite. Once in my teens I fabricated a york to a 350 chevy and a mustang underdash to my old truck, the unit would throw snow at you when the humidity was right but it would kill the engine at stop lghts...lol...(over charge)...and as I said before r12 cools better at low RPMs than 134a, not in general

Not being an AC guy like you guys seem to be, what is the oriface tube and where is it located? I'm just a nuts and bolts guy and plan on physically swaping out out the necessary parts and let a real AC guy do the system purge etc. I'm looking for the best method to get my AC working again. I do live in Dallas,Texas so it gets real hot here. (average 106 last week) so whatever I do I want to be sure it will cool when I'm through. If doing a full change over to R134 is required I'm OK with that but if I can get by with new hoses, a system purge and recharge thats OK too. Don't they still sell R12 at just a higher cost?

They do still sell it at a very high price. Here in AR 134a is $14 and r12 runs around $90 for the same OZs. The orifice tube is in the liquid line return to the condenser but the shop where you take it will remove it, flush the system, and replace it with a new one. If your just changing the hoses, I would recommend spending just a little more for barrier hoses and replace all Orings before taking it in...save $$$

 

[RacerX]

The 71-73 Mustangs don't have an orifice tube. They have an expansion block at the firewall. The hoses screw into the expansion block and the evaporator core screws into it from the passenger compartment side.

Orifice tube didn't show up until the fox body Mustangs if I recall correctly.

 

[terry kelley]

The 71-73 Mustangs don't have an orifice tube. They have an expansion block at the firewall. The hoses screw into the expansion block and the evaporator core screws into it from the passenger compartment side.

Orifice tube didn't show up until the fox body Mustangs if I recall correctly.

would that need to be replaced with an R134 conversion?

 

[RacerX]

Replaced with another expansion block. I haven't yet checked to see if they are still available.

If it was working fine and the system has been sealed and pressurized, chances are it's OK.

If it's been discharged for any length of time, I'd replace it.

 

[Jeff73Mach1]

I would recommend talking to someone that deals with these conversions all the time. http://www.oldairproducts.com/catalog/contact_us.php

When I installed aftermarket air, it cost me about 1200 bucks

When my 89 Bronco's compressor went out years ago, it ultimately required a compressor, receiver/dryer, hoses, orifice tube, and a condenser before the system would work without blowing the compressor seals after a few minutes. I had let a local shop do the repairs and they could not get the system to work with just hoses a receiver dryer and a compressor. Compressor seals would blow after a few minutes or at best days of operation. By the time they gave up and finally took it to a ford dealer, they had gone thru 5 compressors. Ford's charge to them (and this was over 10 years ago) was about 1200.00

Trash in the system can be vacuumed out to some degree, but a contaminated system can lead to you spending time and money repairing it only to have a seal fail and be back to square 1. Look at the cost of a complete modern system before you make up your mind

 

[caspianwendell]

The 71-73 Mustangs don't have an orifice tube. They have an expansion block at the firewall. The hoses screw into the expansion block and the evaporator core screws into it from the passenger compartment side.

Orifice tube didn't show up until the fox body Mustangs if I recall correctly.

Duh...this is true...I think I need a nap

 

[RacerX]

Duh...this is true...I think I need a nap

Senior moment?? jk!!

 

[caspianwendell]

Duh...this is true...I think I need a nap

Senior moment?? jk!!

Part timers disease...LOL...just did an A/C install on a 8BA flat head and 2 repairs and all with expansion valves too.

 

[terry kelley]

Duh...this is true...I think I need a nap

Senior moment?? jk!!

Part timers disease...LOL...just did an A/C install on a 8BA flat head and 2 repairs and all with expansion valves too.

I made a call to the guys at Classic Auto Air yesterday and the guy there told me that I can use the original compressor by simply draining and changing the compressor oil over to the R134 type. I will need a new condenser coil, dryer, hoses and expansion valve/block. The total price is about $635.00 for parts. He says that the compressor and evaporator coil are interchangeable with freon type as long as they are in good working order and the compressor oil is changed over. Does this sound right to you guys? The price isn't too bad either considering a complete changeover. I think my compressor is OK, just out of freon. It doesn't try to engage but isn't that normal when there is no charge in the system? Is there an easy way to verify if the compressor is OK. It's on the car now and everything is hooked up. No bearing noise or other physical signs of defect. Thanks for all the support so far!

 

[caspianwendell]

It is true that the compressor will work with other oils but will need drained and will require removal. you can inspect the clutch face and look for traces of an oil leak which will be lines from center out indicating a front seal issue, but without a tear down you just never know. Everything he said is accurate so sounds like you found a good shop, but ask if when charged and a problem surfaces if they will charge you for contaminated freon? Some shops will not reuse freon especially from a conversion.

 

[terry kelley]

It is true that the compressor will work with other oils but will need drained and will require removal. you can inspect the clutch face and look for traces of an oil leak which will be lines from center out indicating a front seal issue, but without a tear down you just never know. Everything he said is accurate so sounds like you found a good shop, but ask if when charged and a problem surfaces if they will charge you for contaminated freon? Some shops will not reuse freon especially from a conversion.

The guy I talked to works for the company that sells the aftermarket AC kits. One other thing I have read conflicting information on is the operating pressures. Some say the conversion to R134a is too high for the original York compressor (about 10 5 higher and will blow the gaskets)while others say that it's not enough to worry about and the compressor won't even notice it. I'm wondering if the blown gasket issue is related more to not changing the compressor oil when someone did the conversion? Any ideas?

 

[c9zx]

It is true that the compressor will work with other oils but will need drained and will require removal. you can inspect the clutch face and look for traces of an oil leak which will be lines from center out indicating a front seal issue, but without a tear down you just never know. Everything he said is accurate so sounds like you found a good shop, but ask if when charged and a problem surfaces if they will charge you for contaminated freon? Some shops will not reuse freon especially from a conversion.

The guy I talked to works for the company that sells the aftermarket AC kits. One other thing I have read conflicting information on is the operating pressures. Some say the conversion to R134a is too high for the original York compressor (about 10 5 higher and will blow the gaskets)while others say that it's not enough to worry about and the compressor won't even notice it. I'm wondering if the blown gasket issue is related more to not changing the compressor oil when someone did the conversion? Any ideas?

If you convert to 134a you will only use 70-80% the amount of refrigerant you'd need with R-12. I've had mixed results with conversions to 134a. You might want to contact these people and tell them what you want to achieve, they have been very helpful to me especially on original/restored parts. You'll like the Mustang catalog cover as well. Chuck http://www.classicautoair.com/catalogmustang.html