Condenser Replaced - a few pics

[r67northern]

Hi All,

This past weekend I went through a condenser replacement on the '90 Burb. I had a couple of interesting experiences along the way so I thought I'd post an update. The background to the burb's system is that it was converted several years ago to R134a and over the past few years has had everything replaced except the condenser. I've done most of the work myself, but occasionally farmed it out.

I decided it was time to replace the condenser when I fixed a leaking evaporator (full disclosure: I farmed that one out because of some time constraints) and it still wasn't cooling well. I couldn't afford to throw more money at someone else to work on the system so I ordered the parts, took a day off work, and went after the condenser myself.

The part I ordered is the "OE" ACdelco unit:
http://www.amazon.com/dp/B000C9DGMI/

It arrived and it was much smaller than the original. The height matched well, but the length of the unit (side to side) was reduced. The fin design is also highly updated and I expect that its total heat exchanger area is as good or better than the original that came with the truck. Still, mounting was going to be an issue because of the size change, despite the fact that delco promises this is original equipment. Here's the original that came out of the '90:

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Since I'm an engineer I can convince myself that heat exchanger technology could improve in 25 years so, if I could get it to mount, I'd give it a shot. It turns out that you can re-use the mounts for the condenser IF you move the brackets from the original outer bolt holes to the most inner holes on the truck's front surface.

The lower brackets are not bolted in place, but are held in place with some tabs and slots much like the radiator. The passenger side lower mount had unused slots that I could re-purpose for this new condenser design. The driver side required that I use the rubber mount without alignment slots. So far it is holding without problems.

Here's a photo of one of the mounts with the new condenser installed. The mount has been moved from right (original) to left (new) positions to hold the condenser centered in front of the radiator. The view is basically from the top to the bottom, along the passenger side:

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With the new condenser centered, the hose lines match up to the original compressor lines well. The upper mounts also align fairly well to some unused bolt holes. Here's a picture of the condenser installed (a trans cooler is attached in front of it):

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So the upshot is: the new design will fit if you don't mind moving mounts around. The new design also cools well, and the a/c is running much colder than it has in the past few years. I hope that helps just in case anyone feels like using an "OE" delco unit.

Now I need to think about getting the old girl repainted!

 

[yevgenievich]

I am possibly looking at doing this as well. AC is just not keeping up at idle under sun with 40* outside temps. How much colder is it running?

 

[r67northern]

I'm away from the truck for a couple of days. Let me pull the temp for you when I get back.

 

[yevgenievich]

is the condenser parallel flow design?
Found they have a retrofit unit for older trucks:
part number:636420
http://www.oreillyauto.com/site/c/detail/OMR0/73642.oap?ck=Search_636420_-1_710&keyword=636420+

 

[r67northern]

is the condenser parallel flow design?
Found they have a retrofit unit for older trucks:
part number:636420
http://www.oreillyauto.com/site/c/detail/OMR0/73642.oap?ck=Search_636420_-1_710&keyword=636420+

Hi All, that Oreilly looks like the one - it is certainly a new parallel flow design versus the old condenser that came out.

I checked the temperature this morning after walking away from everything for a few days. It was pumping out about 50F (10C) with an outside temperature of 78 and very humid. The original temperature before the swap was about 70F (21C).

Keep in mind that the system was running without the heater core in the loop, I have a bypass installed that I like to use in the summer months.

So far so good. It's working better than it has in years.

 

[yevgenievich]

I am looking forwards to getting this done then. Already picked up the condenser. Currently at idle I get 22C out of the vent with outside temps at 40.5c . It works great if it is 30C outside(vent temp at 3-4 C at low fan speed).

 

[r67northern]

I am looking forwards to getting this done then. Already picked up the condenser. Currently at idle I get 22C out of the vent with outside temps at 40.5c . It works great if it is 30C outside(vent temp at 3-4 C at low fan speed).

Good luck, it wasn't a bad swap at all once I committed to repositioning the mounts and pushing ahead. You're probably on top of this already but don't forget about adding the additional ester oil needed for a condenser swap. Are you thinking about doing the accumulator and orifice tube too? I've heard that's typically recommended, and I've tried to do that whenever I've done surgery on the a/c.

Best from Louisiana.

 

[yevgenievich]

Swap was very easy, i just had a major time delay snag in getting the system charged back up using the recovery tank. Ended up picking up new cans for recharge. Even pulled vacuum on the hose after changing between cans before opening back to the system. Had to notch lower brackets to fit correctly. I have just replaced dryer/orifice tube/compressor last week, so this time just replaced the orifice tube. New compressor turned out to be just as or even more noisy as last one.

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[r67northern]

That's looking good - wish I had thought about getting out the black paint. Maybe I'll go back in and paint it up a bit.

 

[yevgenievich]

Dropped idle temp by 6' C out of the vent with similar outside temp. Also, i have used PAG150 oil as that is what compressor calls for and is what i have put in during compressor replacement.

 

[r67northern]

Put a few hundred miles on the truck - a/c did great until the compressor seized. Good grief, that was new last summer. Looks like I'll have the opportunity to flush some lines out and get some paint on the condenser parts that just went in.

 

[yevgenievich]

Put a few hundred miles on the truck - a/c did great until the compressor seized. Good grief, that was new last summer. Looks like I'll have the opportunity to flush some lines out and get some paint on the condenser parts that just went in.

Put in PAG 150 oil when replacing the compressor if going with r4 again. Other option is to convert to sanden flx

 

[r67northern]

Put in PAG 150 oil when replacing the compressor if going with r4 again. Other option is to convert to sanden flx

I hadn't run across Sanden before I googled them just now, are they recommended?

As for the PAG - I've read it isn't interchangeable with earlier R12 systems, and with the long lines in the suburban that go all the way to the back, I'm not convinced that all of the old oil has ever been flushed out, that's what set me on Ester oil in the first place. Thoughts?

Thanks!

 

[yevgenievich]

I hadn't run across Sanden before I googled them just now, are they recommended?

As for the PAG - I've read it isn't interchangeable with earlier R12 systems, and with the long lines in the suburban that go all the way to the back, I'm not convinced that all of the old oil has ever been flushed out, that's what set me on Ester oil in the first place. Thoughts?

Thanks!

Sanden flx7 using vintage air style brackets and modified hoses can be used. Supposed to work better and last longer than r4 compressors. As for oil, if lines blown out with compressed air then it should be ok. Most oil collects in the dryer.

GM TSB on the R-12 to 134a conversion process:


A/C - Retrofitting R-12 Vehicles to R-134A


Group Ref.: HVAC

Bulletin No.: 331226

Date: January, 1994

INFORMATION

SUBJECT:
RETROFITTING R-12 VEHICLES TO R-134a

MODELS:
1994 AND PRIOR YEARS, PASSENGER CARS AND TRUCKS WITH R-12 A/C SYSTEMS

There has been a great deal of information presented by the media regarding the need to retrofit vehicles produced with R-12, to a substitute refrigerant. This bulletin will outline GM's position and future plans on this subject.

Most important, there is currently NO requirement to retrofit any R-12 vehicle. Vehicles built with R-12 can be serviced with R-12, as long as the refrigerant is available. At some point in time, R-12 may become either too scarce or too expensive to economically justify service on some vehicles with R-12. By that time, GM will provide you with instructions on retrofitting those vehicles from R-12 to R-134a.

GM vehicle divisions, platforms, and component suppliers have been actively working on the details of retrofitting R-12 vehicles. An enormous amount of work is required to determine how hundreds of vehicle models can be satisfactorily retrofitted. Additional information will be provided as it becomes available.

The following items contain important technical information that should answer many of the questions, and correct some misconceptions reported in the media.

SUBSTITUTE REFRIGERANTS

R-134a is the only approved substitute refrigerant that GM recommends and it should only be used if a complete retrofit procedure has been performed. None of the other refrigerants currently being marketed as replacement or drop-in substitutes for R-12 are approved for use in GM vehicles.

R-12 and R-134a are not interchangeable. R-134a cannot be added to fill a low R-12 system. The combination of the two materials can cause high system pressures, which could cause damage to the system.

Retrofitting an R-12 vehicle to R-134a requires careful preparation to insure that neither the vehicle nor the A/C service equipment has become contaminated.

RESIDUAL MINERAL OIL

The concern that mineral oil is chemically incompatible with R-134a and/or PAG lubricant has been proven to be untrue. A normal charge of mineral oil left in the A/C system after a retrofit to R-134a will not damage the system. Mineral oil, however, does not mix well with R-134a, and will not provide adequate lubrication. Tests on both the orifice tube and TXV systems show that the mineral oil parks in places such as the accumulator, and does not appreciably affect performance or damage the system. The retrofit service bulletin will specify the correct oil to be used. It is important that this oil recommendation be followed carefully.

RESIDUAL R-12

Residual R-12 left in a system, due to improper retrofit service procedures, may result in system damage unless the residual R-12 is kept below the 2 percent limit specified by the Society of Automotive Engineers' Specification J-1661. New service methods are being developed to minimize the level of R-12 remaining in the A/C system after the retrofit procedure is completed. Following these new procedures will be critical to insure that the above limits are met.

SYSTEM FLUSHING

R-11, a material commonly used as an A/C system flushing solvent, has been found to be chemically incompatible with PAG lubricant. Technicians should be aware that residual R-11 remaining in an R-12 system will be very damaging if the vehicle is retrofitted to R-134a later in its life. For many years GM has recommended the use of in-line filters as an alternative to system flushing.

SYSTEM FLUSHING, USING EITHER R-11 OR ANY OTHER FLUSHING MATERIAL, IS NOT APPROVED BY GM FOR ANY A/C SYSTEM.

DESICCANT PROTECTION

It has been reported that the desiccant (moisture absorption material) used in 1992 and older R-12 A/C systems is incompatible with R-134a and PAG oil. The older desiccant was designed specifically for R-12 systems, but testing has shown that it is NOT necessary to replace the older desiccant just because the vehicle is being retrofitted to R-134a. 1993 and newer GM vehicles use desiccant designed to be compatible with both R-12 and R-134a systems.

The amount of desiccant used in most GM vehicles is designed to last for at least seven years. To help maintain adequate protection for vehicles that must be retrofitted, it is recommended that the accumulator/dryer, which contains the desiccant, be replaced if the vehicle is more than five years old.

"O" RINGS

While continuing to service with R-12, be sure to use "O" rings and seal materials which are compatible with R-134a and PAG oil. This practice will eliminate concern in case the vehicle requires retrofitting later in its life. All "O" rings and seal materials available from GMSPO are compatible with R-134a systems.

RETROFITTED SYSTEM PERFORMANCE

Currently, it appears that for most GM vehicles, the retrofit procedure will require minimal changes to the existing system. Some vehicles may need additional parts and/or procedures to provide acceptable performance and/or durability. Our testing has shown that vehicles that have undergone recommended retrofit procedures will, in most climatic conditions, be minimally affected in terms of A/C performance.

SERVICE POLICY

Basic service policy is as follows:

During Warranty - If an R-12 produced vehicle A/C system must be repaired or recharged under warranty, repairs will be completed using R-12. If R-12 is unavailable or unaffordable, GM will notify the dealer body and will pay for the warranty repair and the retrofit to R-134a.

NOTE: It a customer requests that an in-warranty vehicle be converted to R-134a, and the R-12 system is functioning properly, the customer will be expected to pay for the retrofit.

Out of Warranty - The cost of the conversion will be the responsibility of the customer.

 

[r67northern]

Thanks for the info, looks like a good way to go.