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sendo

PARALLEL FLOW A/C EVAPORATOR

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short answer is no. i believe you need to replace the expansion valve and poa

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flush the system remove all oil. i use Alcohol but you can find other products to use. Rob also had a pretty good write up on rebuilding his system and i believe he went r134 also.

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If your old evaporator is not damaged you can remove it and flush it out real well.  I worked with Old Air Products in Ft. Worth Texas.  I did not need to replace my condenser or evaporator coils.  Old Air Products told me to just flush them both out real well with denatured alcohol.  I got it at Home Depot in a gallon can for around $16.  I flushed them out until no discolored alcohol came out.  They told me it could be done with them mounted in the car but I found that due to the mess it is better to just remove them.

If your old system has been sealed there will still be old oil in all of the lines and other areas of the system and it needs to be flushed.  You may be able to take it to an AC shop and let them flush the entire system but not sure how much that would cost.  

I replaced all of the lines except the metal one that runs across the front of the condenser coil.  I also replaced the drier/accumulator, expansion valve and POA valves.  My lines still looked brand new but due to the density of the R134 I purchased all of the rubber lines because they have a barrier layer to prevent leakage.  I also had my compressor rebuilt by Old Air Products.

It looks like the evaporator you are referring to is actually sold by Old Air Products.  Old Air Products I think has a 1 year warranty.  I think the whole deal of the compressor rebuilding, new lines, drier, expansion valve and POA valve cost about $1000..00.

I would replace at least the rubber lines, POA valve, Expansion Valve and drier/accumulator.

Here is a link to the evaporator coil that Old Air Products sells:  https://www.oldairproducts.com/product/10-6177-evaporator-coil-

rob

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I purchased a NOS compressor and will be repairing my entire AC system new spring. 

Thank you for this information as I will need all the help I can get.

I have relays I'm told I should replace?

I know nothing about AC.

Except roll the windows down and drive fast.

 

 

 

 

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first step is make sure to flush the system. all your old oil and metals are floating in there. I like to break the lines apart and use a siphon blow gun to blow the alcohol through. dont do this with your valves in place. keep us posted

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4 hours ago, Ted said:

I purchased a NOS compressor and will be repairing my entire AC system new spring. 

Thank you for this information as I will need all the help I can get.

I have relays I'm told I should replace?

I know nothing about AC.

Except roll the windows down and drive fast.

 

 

 

 

Ted,

Just because it is a NOS compressor does nor guarantee the seals have nor dried out after all of these years.  The oil in the system helps to keep them from dry rotting so after sitting on a shelf all these  years the seals could have dried up.  Not saying they are dry rotted but before charging a system I would be inclined to have them checked.

rob

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Fortunately the compressor had oil in it with the plugs .

I was going to have it flushed by a local shop when its completed next spring. 

 

May I ask..

I have the OEM compressor off my car... its completely siezed..

 Is it worth anything.. or rebuilding?

 

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not sure what they are worth but most are rebuildable even seized. is the sticker still on it. 

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It is somewhat. 

Its torn bad and mostly unlegible.

It's a Harrison for the BBC.

 

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they make the labels andni believe you can get the numbers to match. the label gives you the date code which some like for restorstion purpose

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As you see it's in bad shape and very difficult to make out much for numbers. 

I managed to find the same replacement within 20 minutes of home.

I'm trying to keep this as original as possible plus some upgrades under the hood that everyone has been doing. 

I have all the OEM parts removed from the car .

 

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Sendo,  the evaporators available for our cars (including the one you linked to) are identical to the original design. It has one tank on each side and the refrigerant goes from one side to the other once. I believe even modern A/C systems have evaporators like this.

As I have the engine out of my car, I removed the evaporator and poured a quart of A/C flush in it and swished it around a while, then I blew air through it until it was dry. Then I installed a new ACDelco expansion valve (15-5774) and used some of that stretchy A/C rubber caulking to re-seal the top tube around the valve sense bulb.

It's the condenser that needs to be changed when going to 134a. The original condenser is pretty much one tube that keeps going to the other side, they call it "serpentine". It's very inefficient, more so with 134a.

For 134a, you need a parallel flow style condenser. There are universal units by size in the aftermarket but have no mounting provisions and the fittings are never where they're needed.

Classic Auto Air offers a "direct fit" parallel flow condenser, it's costly at $290.00.  It's full width like the original and I'm sure it bolts right up and no holes need to be made for the fittings.

https://www.ebay.com/itm/70-72-CHEVELLE-MONTE-CARLO-A-C-CONDENSER-PARALLEL-FLOW-Air-Conditioning-AC-134a/400870184701

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37 minutes ago, Paul Bell said:

It's my understanding that a modern Sanden compressor is way better for 134a. They make kits that allow one to mount within the original brackets on your engine. The SD7 has seven pistons and are excellent.

https://www.originalair.com/gm-compressor-upgrades

Thank you for that help.

I'm making a stop tmrw at the shop..

I'll discuss all this with them.

 

I am a licensed mechanic and have been since 1988.

I'm disabled now and cant do the physical work.

I'm fortunate to have a local shop that can work on a pre OBD car...they also own a few...mopars...

 

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I restored my Air Conditioning over the winter and converted it to R-134.  I used the ORIGINAL condenser and evaporator but I removed them from the car, drained the oil from them and fully flushed them out with Denatured Alcohol.  I sent my compressor to Original Air Products in Texas and had it rebuilt for R134.  I also ordered all new rubber "barrier" lines that are recommended for use with the 134.  I also ordered new expansion valve, drier/receiver and POA Valve. I ordered all of my parts from Original Air Products.

I really enjoyed having my Air Conditioning this past summer.  On Sunday or this week it was 90 here in Pittsburgh and I headed out to a car cruise, AC blasting the whole way.

rob

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2 hours ago, Rob Peters said:

I restored my Air Conditioning over the winter and converted it to R-134.  I used the ORIGINAL condenser and evaporator but I removed them from the car, drained the oil from them and fully flushed them out with Denatured Alcohol.  I sent my compressor to Original Air Products in Texas and had it rebuilt for R134.  I also ordered all new rubber "barrier" lines that are recommended for use with the 134.  I also ordered new expansion valve, drier/receiver and POA Valve. I ordered all of my parts from Original Air Products.

I really enjoyed having my Air Conditioning this past summer.  On Sunday or this week it was 90 here in Pittsburgh and I headed out to a car cruise, AC blasting the whole way.

rob

Rob do you notice the difference between the r12 and theb134 refrigerant?

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To tell you the truth Antoine, with this Monte I never experienced the AC working with the R-12 so I can not answer that question.  I can tell you I was running it on Sunday and it was over 90 degrees and high humidity and it worked fine.  I feel if I had maybe gone with a new evaporator and and condenser coils it may have worked better but I could not swear to this.  I have heard that the 134 does not cool as well as the R-12 but I don't know.  If your car was working with the R-12 I would maybe stick with the R-12.  I do know, based upon what I have read and been told that the R-134 is a bit thinner in consistency and have been told if you don't replace the rubber lines with "barrier" rubber lines it can seep through the old rubber lines and ever the compressor seals.

I hope this helps you.  If your system has been open to the air for any period of time I feel you need to replace the drier/receiver.  Not sure what else would need to be replaced though.

rob 

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There's quite a few conversations over at the Chevelles forum about converting to 134a.

The general consensus, including from a few A/C savvy people, is that the parallel flow condenser and Sandon rotary compressor are improvements over the original equipment when converting to 134a refrigerant.

134a is not as efficient as R12 is so 134a systems are designed to have higher capacity components.

Old Air offers an upgrade for the A6 compressors used on our cars with higher capacity:

https://www.oldairproducts.com/product/21-2201hp-compressor-pro6ten-high-pressure-single-groove

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i know that r134 runs at higher pressure especially on the high side.  the condenser is different to give more surface area to better help with heat exchange. I know at one time it was said the ruber lines would leak because the molecules are smaller for 134.  I have changed over a lot of cars in then 90s but always felt that r12 cooled better. now with a little more knowledge i think with the right condensor and metering system it might be possible that 134 is the same or better

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okay got my parallel condenser now looking for the grommets, do I need grommets for both side? anyone know the part number or where to get them?

thanks, Sendo

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