Sanden compressors

[RivNut]

1) Does anyone have experience, or even know if it’s conceivable, to run a new Sanden style compressor with an OE air conditioning system?  I need to restore/renew/replace the air conditioner in my ‘64.  
2) Or is it smarter to just replace the entire system with something modern from Vintage Air or Old Air Products?  
3) For those of you who have moved to a modern system, what did you do for a control panel?  Use what the manufacturer offered or make it work with your existing controls?

Ed

 

[telriv]

Ed,

 

As far as I know the Sanden compressor is a bolt-in & bolts to the existing Alt/A/C bracket.

Since it's smaller & lighter you don't need the rear support bracket.

Leave EVERYTHING else the same as stock including the controls.

With ANY of the aftermarket stuff they ONLY recycle inside air so you have NO fresh air available from the exterior & blending heater with A/C is marginal.

Save yourself the grief & frustration & reuse what you already have IF it's operational.

Use R-12 as it will use everything you have already.

What MOST don't say about 134 is in reality it requires a different A/C condenser, evaporator & receiver dryer/accumulator, hoses, oil, complete flushing etc.

AND, R12 cools better & has come down in price in recent years.

Just my thoughts.

 

Tom T.

 

Edited December 6, 2023 by telriv (see edit history)

[NTX5467]

Rather than the Sanden, there is a Denso compressor that, other than the front clutch cover, looks identical to an A6 and is a direct bolt-in replacement.  Made of aluminum so it's lighter, too.

 

Other than what many sell, there are about 16 different "backs" for the Sanden compressors.  ONE mates directly to the GM hose set-up, too!!!  Most people do not know it exists, it seems.  There is also a spacer to make up for the length difference so the OEM hoses hook up to it and to not physically change locations due to the Sanden's shorter length.

 

R-134a seems to work best with a parallel flow condenser.  Some vendors sell bolt-in units for older cars.  POA valves are adjustable, so turning the adjustment screw 3/4 turn CCW and it is set for R-134a gas.  Same with other GM valving.

 

Purge the system of ALL existing R-12 oil.  Use the recommended R-134a oil, ensuring the compressor has enough in it to start with, although it should be pre-filled with it.

 

Check ALL of the vendors for the best price, too.  No real need to re-invent the wheel, just put some new wheel covers on it.

 

Just some thoughts,

NTX5467  

[TexRiv_63]

Ed,

As you may remember I replaced the a/c on my 63 Riv with a complete Vintage Air setup back in 2007. It was a lot of work but when done it did a good job of cooling the car in Texas heat. I agree with most of what Tom and NTX said above but a lot depends on what you are starting with. If you have a complete system still holding pressure you could conceivably replace just the compressor and dryer but the system will not be as efficient with R-134. But if your current system is open to the air or missing parts trying to preserve it may not be possible.

 

I took a different tack on my 66 Dodge Monaco wagon. It had a closed and operating stock system already converted to R134 and after a charge it worked, but soon the compressor gave up the ghost. I did a partial conversion using a new Sanden compressor, expansion valve, dryer, parallel flow condenser, and most underhood hoses. I reused both evaporators, (it had dual a/c) underhood hardlines and all controls which were in working condition. This was a fairly easy job and the results were great. If you have a little time read my forum thread on this job, it may be of help.

 

 

 

 

 

[1965rivgs]

14 hours ago, TexRiv_63 said:

Ed,

As you may remember I replaced the a/c on my 63 Riv with a complete Vintage Air setup back in 2007. It was a lot of work but when done it did a good job of cooling the car in Texas heat. I agree with most of what Tom and NTX said above but a lot depends on what you are starting with. If you have a complete system still holding pressure you could conceivably replace just the compressor and dryer but the system will not be as efficient with R-134. But if your current system is open to the air or missing parts trying to preserve it may not be possible.

 

I took a different tack on my 66 Dodge Monaco wagon. It had a closed and operating stock system already converted to R134 and after a charge it worked, but soon the compressor gave up the ghost. I did a partial conversion using a new Sanden compressor, expansion valve, dryer, parallel flow condenser, and most underhood hoses. I reused both evaporators, (it had dual a/c) underhood hardlines and all controls which were in working condition. This was a fairly easy job and the results were great. If you have a little time read my forum thread on this job, it may be of help.

 

 

 

 

 

  My experience with conversions places my opinion in a much more conservative status regarding "changing stuff" as compared to most folks but I don't see mention of the one item that is critical and MUST be added when converting from R12 to R134 and that is an R134 compatible refrigerant oil. When converting, the proper oil in the amount of full system capacity is the one thing that MUST be added or compressor failure WILL occur.

  There are oils that are compatable with both R12 and R134 and oils which are only to be used with either refrigerant.

  I recently sold a $500 '85 Riviera that I used as a go to work car for 5 or 6 years. It was rusty but very low mileage so the AC system was in very good condition. I did a conversion on the car, only changing the refrigerant to R134, replacing a Schroeder valve and adding the appropriate refrigerant oil just after I purchased it and put 50K miles on the car. It sat idle for a handful of years on the back forty until a neighbor kid came along to use it for the engine to replace an always junk HT4100 on a Cadillac Eldorado. When I started the engine for him, out of curiosity, I put on the AC and it still had enough refrigerant to blow cool. ALL I did years before was make a 5 minute repair, add R134 and the correct refrigerant oil, nothing more! I've done a ton of conversions over the years in much the same way with acceptable results with one consistent observation, the R134 will not cool as well as R12 unless one gets into changing components, specifically the condensor.

Tom

[RivNut]

@1965rivgs Is there an OE Type condenser that can be used in an R134a conversion in a 1st generation Riviera or does one have to look in the aftermarket?  Out of curiosity, what is/are the difference/s?

 

Ed

[NTX5467]

I'm not sure why the R-134a system needs the parallel flow condenser, but all OEM condensers for R-134a are that way.  R-134a is more sensitive to over-charge, more so than R-12.  The earlier recommendations were to start at an 80% of the R-12 charge.  Then gradually add R134a until cooling peaks, then stop.  Which usually ended up at 90% of the R-12 charge.

 

When I came back from the BCA National Meet in Flint, 2003, there were conversations about swapping the existing POA valves for what the aftermarket was selling as "POA Eliminators", which basically made the system into a cycling system, as the later CCOT systems were.  My research on R134a conversions had already led me to the www.ackits.com website.  Run by some a/c people in Arizona.  Where I first discovered the variable orifice valve for the CCOT systems.

 

In it was a thread on R134a conversions.  At that time, there were three oils for R134a, depending upon where the vehicle was produced.  I knew that in a couple of years, there would probably be an oil which would be compatible with ALL gasses, which did happen.

 

In the R134a conversion thread were comments about decreased cooling.  We had already seen that with the first year of R134a in Chevy pickups, at that time (later 2003).  Then, something interesting was revealed!  That every modulation system for R12 gasses was "adjustable".  GM literature claimed they were not, with defective units changed under the original vehicle warranty were to be returned to GM.  Yet when Ford started to use the GM A-6 compressor on Lincolns, they also went to a POA system, too.  Unlike the GM literature, the Ford literature had a procedure to do an adjustment for poor cooling.  Which meant that the POAs were adjustable.  Obviously, these modulation devices had all been adjustable, all along, back to the first Hot Gas Bypass Valves and such in the GM systems.  How else might they do their calibrations on the assy line where the valves were built?

 

GM's warranty orientation was that they would not pay for the same repair code twice, so they did not want techs messing with the POA adjustments, lest multiple complaints happen, over time.  So they wanted the POAs replaced and returned to them, so they could then deal with their Harrison Division operatives for quality control issues.

 

On the POAs, one some years, the adjustment item is on the input side, other years, it is on the output side.  Turing the adjustment item 3/4 turn CCW should drop the evap core pressure to 26" Hg from 27.5" Hg, which then puts the high side-low side pressures back into a similar relationship as with R-12.  Several people in that thread, with different GM systems, all said that when the POA was readjusted, their a/c vent temps dropped into the low 40 degrees F range, just as it had been with R-12.  With NO other alterations to the system.  Chrysler's EPR valve is the same way, just easier to get to.  So, adjust the POA valve for R134a, clean the system of the old R-12 oil, recharge to 90% of the R-12 charge, and that should be "it" . . . according to that old thrad at www.ackits.com (or its later version).  

 

In the gas handling situations at the a/c shops, all shops initially had one recycling machine for R-12 and one for R134a.  Each one dedicated to their particular gas.  No contamination was allowed.  In those times, I had a friend who worked for Four Seasons and wrote their service manuals.  In doing a conversion, he said that the system would be hooked to a R-12 recycling machine.  The machine would be set to circulate full liquid through the system to collect all of the gas from the system, with any oil (which would be separated-out by the machine).  Once that had been done, the R-12 machine would be unhooked and the R134a machine hooked up.  After pulling the initial vacuum on the system, then the new R134a AND compatible oil would be added.

 

Now, there are some side issues.  The Sanden is an 8 cubic inch displacement compressor whereas the A6 is at or a bit more than 10 cubic inch displacement.  GM used the A6 on everything from the factory add-on kits for 1969 Opels to Greyhound busses, with the pressure modulation systems doing their magic as to how much load the compressor saw and the related load on the engine.  Which means the Sanden has lower capacity, but will need to turn faster for the same level of cooling, in theory.  As GM used such a small pulley on their normal car A-6s, it would be hard to get a smaller pulley on the Sanden to turn it faster.  Which may be where the parallel flow condensers come into play?

 

Another issue is that any car from the 1960s is very poosly-insulated against heat and cold.  No continuous insulation above the headliner, for example, other than some insulation to decrease drumming of the roof panel.  No continuous insulation under the carpets, other than for heat intrusion from the floors and engine compartment.  No insulation in the doors.  Generally, anything that is there is for sound control rather than making the hvac system work better, by observation.

 

Modern vehicles are designed to have much better continuous sound and heat/cold insulation, by observation.  Generally smaller volumes, too.  Result is that the 8CID Sanden cools them well.  With a cycling compressor system and a parallel flow condenser that is at big as the vehicle's radiator (as to height and width), rather than like they were on the earlier R-12 systems.

 

In some research the other night, I discovered that the main a/c vendors now sell drop-in replacement parallel flow condensers for many older vehicles.  Attaching to existing a/c lines.  Add a new receiver-drier and that end of things is taken care of.  Most were about $300.00 USD and painted black.

 

I'm not sure what it would take to expose the front clutch on the Denso A6?  Don't know what it would look like.  But that Denso item looks very much like a Harrison A6 and has all of the same attachments and hook-ups for a drop-in installation.  Usually in the $350.00 USD range these days.

 

@TexRiv_63 found a place to buy everything he needed for the Sanden installation, hoses, crimping kit, etc. for a good price.

 

Just what how far my research has gotten to this point,

NTX5467

[1965rivgs]

37 minutes ago, RivNut said:

@1965rivgs Is there an OE Type condenser that can be used in an R134a conversion in a 1st generation Riviera or does one have to look in the aftermarket?  Out of curiosity, what is/are the difference/s?

 

Ed

Ed,

  I`m not current regarding what the aftermarket is offering for first gen Rivs. As you know, products become available on a regular basis. I would call the aftermarket AC vendors like Old Air Products, etc, to ask what is available regarding a direct fit and more efficient modern condenser core.

Tom