About to do a AC Flush -- Rotted AC Line left open --> Replaced AC condenser, TXV / expansion valve, AC compressor, receiver drier (1 Viewer)

[onemudder]

My rotted PS AC line caused a slow train wreck for 18 months now and have decided to hit the forums here.

So far journey started with:

1) First, with getting the seized AC rotted line out and identifying the correct line to reorder, -- system was left open for months during this time possibly leading to further woes
2) Then decided to replace the condenser, but my mechanic neglected to change the o-rings and all the freon leaked out within weeks
3) I changed the O-rings, vacuumed and pressure held-- but compressor wasn't pulling freon on the recharge
4) Now, I'm about to change the AC compressor (new Denso) and replace the TXV / expansion valve, and drier. clean the evaporator
5) Replace with new o-rings for each component and Nylog oil lubricant
5) Going to add a replacement amount of PAG46 to each component I'm accessing in the system

I figured the open system contaminated the system and destroyed the AC compressor. So I purchased a flush kit with a flushing agent on Amazon but want to make sure I'm not missing anything because frankly, I need this done.


Anyone have experience with an AC flush?

The old compressor is still in, and I want to know if I should flush before the new compressor is installed or afterwards ? I'm wondering about the flushing action on all this.

IIRC each component should ideally be flushed separately, but I'd like to avoid that where possible since it can be a PITA to do this. The condenser is only a few months old and I think it will be good to go.

Thanks in advance.


P.S. I have searched the forums with not alot on this topic other than in the 80 series:

AC evaporator flush recommended?

Any opinions? I had a leak in my '94 AC system (condenser and o-ring at receiver/dryer) last summer. While in the process of replacing my radiator, decided to take care of the condenser at same time. Have the new condenser installed now and about to take to shop to have system evacuated...

forum.ih8mud.com

AC Condenser Flush

1988 FJ62 I'm replaceing the AC compressor and would like to flush the condenser without removing it since the in/out connections are good and show no signs of leaking. But I'm curious about which style these condensers are - parallel or serpentine. The inlet and outlet are on opposites...

forum.ih8mud.com

2006 Land Cruiser 240k miles

 

[hickuptruck]

Not to thread hijack but I was exactly where you are. Except now I'm replacing the AC compressor. How much ac compressor oil is there supposed to be in the Denso unit?

 

[hondarepairman]

Don’t run the flush through the compressor or the expansion valve. You really need to flush all components separate for best results, the whole idea behind flushing is to get all the old oil and contaminants out of the system. You need to insure that the system is clean BEFORE the new compressor gets installed. Wouldn’t be a bad idea to open the system in a few places and run a q-tip down the lines and see what they look like. The oil condition in the old compressor can also give you an idea of failure.

 

[JunkCrzr89]

I think @flintknapper is the resident A/C guru?

FWIW, I’m in a similar boat right now. Just drove 20 hours across the country with no A/C yesterday I need to replace the lines along the DS fender apron and the compressor...

 

[flintknapper]

Not to thread hijack but I was exactly where you are. Except now I'm replacing the AC compressor. How much ac compressor oil is there supposed to be in the Denso unit?

With rear A/C the system will need about 9 fl. ozs of PAG46. With no rear air 8 fl. ozs That is for the entire system. When replacing the compressor only....empty the compressor thoroughly and add back about 4 fl. ozs to the compressor.

 

[flintknapper]

Don’t run the flush through the compressor or the expansion valve. You really need to flush all components separate for best results, the whole idea behind flushing is to get all the old oil and contaminants out of the system. You need to insure that the system is clean BEFORE the new compressor gets installed. Wouldn’t be a bad idea to open the system in a few places and run a q-tip down the lines and see what they look like. The oil condition in the old compressor can also give you an idea of failure.

^^^^^

This is correct. When flushing the system you will need to separate/isolate as many components as possible. Also....recognize that some components (condenser) can not be fully flushed anyway because of their 'parallel' construction. If flushing ONLY to remove oil, dyes and non solid contaminants....you can use a flushing agent followed by a LOT of compressed air to clean/clear the lines.

IF there has been a compressor failure and any chance of metal particles having gone through the system then replacement of certain parts (pretty much everything except your lines) is the only safe way to go.

When evacuating flushing agents with compressed air it is important to build up pressure in the lines/components and then release it. IF you don't see a 'mist' coming out the other end.....you're not achieving what you want.

Use a rubber tipped blow gun and put your thumb over the opposite end of the item you are clearing. Run 75-90 lbs psi of pressure. Do this until there is no more flush agent coming out (mist). Some agents are fast drying which is fine but tend not to do as good a job.

Take the time to do it right. A/C work is tedious by nature and you don't want to have to do it twice.

 

[flintknapper]

I think @flintknapper is the resident A/C guru?

FWIW, I’m in a similar boat right now. Just drove 20 hours across the country with no A/C yesterday I need to replace the lines along the DS fender apron and the compressor...

Damn......!

 

[flintknapper]

onemudder wrote:

My rotted PS AC line caused a slow train wreck for 18 months now and have decided to hit the forums here.

So far journey started with:

1) First, with getting the seized AC rotted line out and identifying the correct line to reorder, -- system was left open for months during this time possibly leading to further woes
Yep.

2) Then decided to replace the condenser, but my mechanic neglected to change the o-rings and all the freon leaked out within weeks
Yep, shame on him. Poor work.

3) I changed the O-rings, vacuumed and pressure held-- but compressor wasn't pulling freon on the recharge
Best to charge first amount (12 ozs) as a liquid, into vacuum through the high side (engine off). You can search that here or I can explain further when you are ready. It is also possible the charging line fitting was over tightened and the seal crushed....preventing flow of the refrigerant. A common mistake.

4) Now, I'm about to change the AC compressor (new Denso) and replace the TXV / expansion valve, and drier. clean the evaporator
Excellent plan.

5) Replace with new o-rings for each component and Nylog oil lubricant
Nylog is your friend. I can not stress this enough. Use it on the Orings and all mating surfaces. Also on shrader valves

5) Going to add a replacement amount of PAG46 to each component I'm accessing in the system
Exactly right. You understand the process.

I figured the open system contaminated the system and destroyed the AC compressor. So I purchased a flush kit with a flushing agent on Amazon but want to make sure I'm not missing anything because frankly, I need this done.
Flushing a system that has been open to atmosphere for a long time is a must.

Anyone have experience with an AC flush?
Yes.

The old compressor is still in, and I want to know if I should flush before the new compressor is installed or afterwards ? I'm wondering about the flushing action on all this.
You will not be flushing a compressor....EVER. So take the old one out...flush the system, make SURE to get all the flushing agent out, then reconnect all of your lines, and components. The hard lines going along the fender wells and firewall can remain connected to one another.

IIRC each component should ideally be flushed separately, but I'd like to avoid that where possible since it can be a PITA to do this.
Yes PITA.....double PITA if you have to do it twice because it would have been a PITA to do it the first time.

The condenser is only a few months old and I think it will be good to go.
Yes IF your old compressor did not seize. You can't flush metal particles from a parallel constructed condenser anyway. Oil, dyes....yes pretty much. But getting ALL of the flushing agent out (with compressed air) is very important or it will break down the oil in the system when you recharge and ruin your new compressor.

A/C work is no fun....there is no getting around that. Do it right the first time and you'll be rewarded with nice cold air for many years. Take shortcuts or do it wrong....and you'll be doing it over again.

 

[onemudder]

Hi guys, thanks for the responses.

@flintknapper I especially appreciate your line by line comments. I am glad I decided to go with this AC flush and your comments are timely as I've been sitting on these parts debating on cutting corners with the onset of heat. I can see how meticulous steps must be taken to do this the right way. I learned a lesson and wish I knew how important it is to pay attention to the small details. AC is definitely an investment and worth doing right as you said. AND, you have a 38 degree system-- JEALOUS!


Having said that right now, after reading Replace A/C Evaporator core & Expansion Valve post I'm being held up on anticipated corroded hex head bolts from the evaporator and need to get my hands on a pair of replacement bolts from Mr. T. There's always something holding me up(!) . ( Toyota part number 90099-04497) I've also managed to lose both my High and low side port caps. (Not a good idea to place them near the windshield and drive off in a hurry).

Also, you mention the rear AC which I often times forget about and good of you to give pointers on that as well.

As one post suggested, I was planning on calling Denso to go over a few things.

I just came across this link to a pdf (attached below as well) further supporting your suggestions:
Teamec-bvba Flushing and Cleaning the A/C System

The PDF says to air dry but I've also heard blowing shop air through the system after the flush at a MINIMUM of one hour to dry out the residual flushing agent from the lines.

As for the evaporator core, reading the PDF on the link it notes "Whenever flushing the evaporator, plan to vacuum the system for at least 2-3 hours." (!!!!)

Thanks for the suggestion of the blow gun as it reminded me why I even bought a high volume one awhile back. I remember seeing something on Youtube dealing with rotted ac lines and they recommended blowing the lines out with a ACME Typhoon attachment** gun and noted the performance. I ended up getting it, but never used it. I am considering using it after the flush and using shop air as well. So, not instead of your suggestions, but in addition to them. I'm curious to see visually what may come out which I suppose could also be done by inspecting the flushing agent afterwards.








**More about the attachment:

• I purchased this: ACME Automotive A680CS Typhoon High Volume Blow Gun $30.45
  and there are others:
• Coilhose Pneumatics TYP-2500CS Typhoon High Volume Blow Gun, 1/4-Inch NPT with High Flow Tip $18.52
• Coilhose Pneumatics EXT24CN-DPB Typhoon 24" Extension, High Flow Safety Tip $20.90
  one of the reviews on amazon says this:
• 5.0 out of 5 stars A Skeptic Converted
  Reviewed in the United States on February 25, 2013
  Verified Purchase
  I was skeptical about the advertised high air pressure from this tool, expecting that the OSHA approval would require a reduction in airflow to reduce decibels. But it lives up to its claims and then some. Unlike most air nozzles which direct air out of a single opening, this gun has a cone-shaped aluminum tip which is ringed with about 50 or 60 small openings that direct the air over the cone. The result is a very focused stream of a LARGE volume of air. Very powerful flow. Well-built, lightweight, with a smooth-action trigger. Liked it so much I bought 6 more for our production crew, and they love them. You can find cheaper guns, but this one's worth the extra cost.
• another review noted to take precautions with this since it can blow the skin off your hand--- will be using leather gloves for this one!
  

 

[flintknapper]

PDF for flushing is spot on. Purging with nitrogen probably not necessary, but pulling a deep vacuum (2-3 hours) is highly recommended after a flush. It takes time to boil off any moisture still in the system.

You have researched well.

 

[onemudder]

Got hit with a never-ending list of emergencies that left me without a window needed to do this right.

Just as I was about to turn back to doing AC compressor removal & replacement, etc, it occurred to me to check to see if the rear AC system also needs to be flushed. Does the open system caused by the rotted PS front wheel well AC line and open lines to the condenser affect the rear AC system? Is the rear AC system separate from the primary AC?

 

[onemudder]

I came across the video demonstration of the Typhoon high volume blow gun. I got mine awhile ago and will be using it in the next few days before and after flushing the components and lines. Will be careful ease the airflow as to minimize any shock.

 

[onemudder]

Update from yesterday --- I was finally able to remove the evaporator. The !#@@#$ allen bolts holding the TXV were pretty much seized. I was finally able to get one out without totally stripping the allex hex head. (Don't use any power tools!) The other head suffered full strippage leading me down the rabbit hole of "what to do nexts". I ended up taking a sawz-all (no, I dont have a dremel) with a new fine blade and made a careful cut to allow me to insert a heavy duty flat head socket to remove it with a rachet. Still, this freaked me out because is STILL wasn't moving and I was afraid I was going to bust the head. For good measure I decided to apply heat by carefully taking a MAPP torch to the TXV and waited for it to cool down. Then I tried it again and was able to hear the first of small gives. Took slow baby steps. If there's interest I will post this separately.

 

[onemudder]

Separately, once I was able to get the evaporator out and cleaning it off, used my AC Flush gun with proper solvent-- it was not flushing out easily, but more like seeping/trickling out. The solvent that dripped out was cloudly and had some trace particles. I flushed it more and the solvent turned clear flourescent yellow (from the AC dye). Damn, I think the evaporator is gone. I just hopped on the Rock Auto site and ordered a Denso Evaporator.

Now this makes me think the condenser I just replaced exactly a year ago which saw only a few weeks of service before the entire system stopped working.

To sum up I'm:

1) replacing the Denso compressor with a new one (got only the rear 14mm bolt out so far and the 10mm High and Low bolts removed) This compressor bolt was a major PITA to remove and I ended up getting a 14mm flex head wrench to access it and it was extremely stuck. Planning on putting the bolt back on with anti-seize and watch the torque. Need to remove the other front two bolts but this requires me to take the oil filter and battery out for improved access. I need the truck for a few days until I get the new evaporator. PITA Suckage ahead!
2) replace the TXV (Denso on hand)
3) Iffy on again replacing the condenser-- see above [unflushable(?)]
4) replacing the evaporator (Denso) -- on its way to me

Wondering if I can get away with the keeing the semi-new condenser in place.

 

[flintknapper]

Separately, once I was able to get the evaporator out and cleaning it off, used my AC Flush gun with proper solvent-- it was not flushing out easily, but more like seeping/trickling out. The solvent that dripped out was cloudly and had some trace particles. I flushed it more and the solvent turned clear flourescent yellow (from the AC dye). Damn, I think the evaporator is gone. I just hopped on the Rock Auto site and ordered a Denso Evaporator.

Now this makes me think the condenser I just replaced exactly a year ago which saw only a few weeks of service before the entire system stopped working.

To sum up I'm:

1) replacing the Denso compressor with a new one (got only the rear 14mm bolt out so far and the 10mm High and Low bolts removed) This compressor bolt was a major PITA to remove and I ended up getting a 14mm flex head wrench to access it and it was extremely stuck. Planning on putting the bolt back on with anti-seize and watch the torque. Need to remove the other front two bolts but this requires me to take the oil filter and battery out for improved access. I need the truck for a few days until I get the new evaporator. PITA Suckage ahead!
2) replace the TXV (Denso on hand)
3) Iffy on again replacing the condenser-- see above [unflushable(?)]
4) replacing the evaporator (Denso) -- on its way to me

Wondering if I can get away with the keeing the semi-new condenser in place.

The same nasty mixture of oil and dye that was in your Evaporator will also be in your Condenser.

Since your Condenser is of parallel construction it is not possible to flush it very well. I leave it up to you.....but since you are this far into the system and will be heavily invested in time (and money), do you really want to take a chance?

A new condenser will come with a new desiccant bag (which you need anyway) and you'll have an opportunity to replace O-rings and seal mating surfaces there if you go with a new one.

A/C work is not something you want to have do twice, will always be my mantra.

 

[onemudder]

Thanks Flint. I was on the fence because it only saw a few hours of service. I ended up ordering a new one. Better safe than sorry. Thanks for chiming in. Would definitely hate to do this all over again!

 

[arkmm]

How did all this turn out? I have a leaky line (discharge line runs on top of the radiator) and while I'm replacing it my dad says I should replace the expansion valve and drier. It looks like the expansion valve is in the dash. How difficult would these 3 parts be to change?

 

[flintknapper]

How did all this turn out? I have a leaky line (discharge line runs on top of the radiator) and while I'm replacing it my dad says I should replace the expansion valve and drier. It looks like the expansion valve is in the dash. How difficult would these 3 parts be to change?

Dad is right.

The drier is really just a desiccant bag on these units. It will look something like this: (may not be your part number)

The tube that holds it is on the side of the condenser.

The TXV (Thermal Expansion Valve) attaches to the evaporator. The evaporator coil is in a housing under the dash behind the glove compartment. It has to come out in order to replace the TXV. There are many, many posts with tips on how to do this.

Use the search function for that.


It would be a good time to replace the evaporator housing seal as well.....to prevent leaks onto your carpet.

 

[arkmm]

Dad is right.

The drier is really just a desiccant bag on these units. It will look something like this: (may not be your part number)

View attachment 3030093


The tube that holds it is on the side of the condenser.

The TXV (Thermal Expansion Valve) attaches to the evaporator. The evaporator coil is in a housing under the dash behind the glove compartment. It has to come out in order to replace the TXV. There are many, many posts with tips on how to do this.

Use the search function for that.


It would be a good time to replace the evaporator housing seal as well.....to prevent leaks onto your carpet.

View attachment 3030097

Man when they said you're the expert they weren't kidding! Thanks a ton for the correct terms to search. I guess its time to order parts!

 

[arkmm]

The TXV (Thermal Expansion Valve) attaches to the evaporator. The evaporator coil is in a housing under the dash behind the glove compartment. It has to come out in order to replace the TXV. There are many, many posts with tips on how to do this.

Use the search function for that.

Ive been doing my research and collecting parts. When you say there's tips on removing the evaporator coil you mean the glove box support cut? I've also seen a youtube of a guy taking out the expansion valve from the firewall side. My only hesitation with that is installing the new one since he didnt show that part. Thanks again for your time and info @flintknapper