Flushing my AC condenser

[Chasander]

Can the condenser be flushed in the car. I’m worried I won’t get all the solvent out of the bottom. I just have a small pancake compressor and it may not push all solvent out. The two  bolts securing it at the bottom are giving me fits. Getting the bolts out may involve removing lower bumper or radiator. 

[JZRIV]

Yes it can be flushed in car but your concern is legitimate. Pushing the flushing agent uphill requires a steady fairly strong air supply. Assume you have a flushing gun kit and special solvent. This is a messy job. They'll be some oil in the condenser and solvent will need to break it down so it blows out with less volume from the pancake. I think you can probably get it done with the pancake but depending on tank size it could take a few cycles.

[NTX5467]

Possibility of using some a/c fittings and rubber hoses to attach to the condenser inlet and outlet, through which the flush fluid can be added, held, then flushed out through?  Flush top to bottom, which might be the best orientation?

 

Install the flush fluid.  When it runs out of the bottom side, plug that hose and keep filling until all if full.  Might need to elevate one side of the car to minimize the possibilities of air bubbles in the serpentine passages?  When full, let it sit for an hour or so.  Then drain and use more flush fluid until what comes out is mostly clean.  Then plug the outlet, refill, and let it sit overnight?  Then complete the flush the next day.

 

Is the flush in prep for R-134a or is that suspicion that the condenser is internally restricted?  Just curious.

 

Just some thoughts,

NTX5467

[avgwarhawk]

From what I recall the solvent dries up in a short period of time. The compressed air will move what it can. Any solvent left behind will dry. 

[Chasander]

It can’t run out the bottom as inlet and outlet are both routed to top. 

[NTX5467]

But you do know which pipe goes to the bottom?

[Chasander]

Yes I can follow it down

[Chasander]

 Borrowed autozone’s flush kit and blew solvent thru condenser, lots of yellow fluid came out. Keep blowing for a long time till no moisture came. Also run solvent thru evaporator seemed to get more crud out of that then condenser I order a new expansion valve, it was different than the Frigidaire valve in that it had a coil of tubing for a sensor instead of a bulb. I decided to use the original one. Trying to but things back together now with rebuilt STV, new A6 compressor, and filter drier.  Finding SAE AC o rings is a bit of a challenge. 
Thanks for all advise. 

Edited August 6, 2023 by Chasander (see edit history)

[Turbinator]

Chuck, when I put in my O rings I mashed them flat. They need to be tight but not mashed flat. I had no luck rebuilding the STV, but really it could have been mistakes on my part. I finally used bypass kit to replace STV and that worked. I’m in hopes you are on your way to cool air.

Turbinator

[XframeFX]

On 8/5/2023 at 2:09 PM, Chasander said:

Thanks for all advise.

Please follow-up with your results, TX.

[Chasander]

I have cold air. Put it all back together and a friend hooked up his gauges and vacuum pump and brought system down to 30”. We let it set overnight and still at 30” the next day. Charged system with R12 until no foam or bubbles in sight glass. Temperature at center vent is varying between 34 and 39 not sure why, it was 72 ambient outside. Controls are set to recirculating. I have no vacuum to STV not sure why. STV with no vacuum would be full cooling. Service manual says I should get 37. 

1. Had STV and filter/drier rebuilt at Original Air group in Tampa

2. New expansion valve from Old Air Products. 
3. New Alma A6 compressor from OReilys. 
4. SAE green O rings from classic Corvette. 
5. Flushed evaporated and condenser. (Reinstalling air box and fitting rubber boot back on was tough). 

Edited August 29, 2023 by Chasander (see edit history)

[1965rivgs]

1 hour ago, Chasander said:

 

  I have cold air. Put it all back together and a friend hooked up his gauges and vacuum pump and brought system down to 30”. We let it set overnight and still at 30” the next day. Charged system with R12 until no foam or bubbles in sight glass. Temperature at center vent is varying between 34 and 39 not sure why, it was 72 ambient outside. Controls are set to recirculating. I have no vacuum to STV not sure why. STV with no vacuum would be full cooling. Service manual says I should get 37. 

1. Had STV and filter/drier rebuilt at Original Air group in Tampa

2. New expansion valve from Old Air Products. 
3. New Alma A6 compressor from OReilys. 
4. SAE green O rings from classic Corvette. 
5. Flushed evaporated and condenser. (Reinstalling air box and fitting rubber boot back on was tough). 

  Just curious...did the new compressor come prefilled with oil? Did you add oil to replace the oil flushed from the evaporator and condensor?

  Generally the low side pressure and hence temp will fluctuate slightly as the expansion valve opens and closes, assuming the compressor is constantly running and high side pressure is consistent. That is normal operation; although I wouldn't expect it to fluctuate that much.

 That ambient temp is not loading the refrigerant system much so maybe check pressures again when the ambient temp is higher and your low side readings may be more consistent.

  Zero or low single digit vacuum level at the STV is normal if the controls are set at max cooling.

  Generally I take temp readings at the outlet closest to the evaporator core for more accurate readings regarding evap temp. In a first gen Riv that would be the passenger side outlet.

Tom Mooney

Edited August 29, 2023 by 1965rivgs (see edit history)

[Chasander]

Compressor came with shipping oil. I drained and refilled with 10 1/2 oz of 525 mineral oil. Manual calls for that. My thinking, all new components and flushed I filled like new. 

[Chasander]

I do not have vacuum to the STV in any position of the temperature control lever. I need to remove dash to access the control module. I hate doing that as the dash is original and very brittle. 

[XframeFX]

7 hours ago, Chasander said:

I hate doing that as the dash is original and very brittle. 

Yes, careful. If the windshield was changed, excess kit (sticky polymer bitumen) from the seal may have a death grip on the front edge of your dashpad.

[telriv]

Just put the car in the sunlight for a few hours to soften the grip.

Works every time.

 

Tom T.

[Chasander]

Couple of issues with A6 compressor. The pulleys are about 1/4” larger, and electrical connectors are clocked in wrong position.