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Sludge.. help!!

tps500 on Sat August 29, 2009 10:03 AM User is offline

Year: 2000
Make: Chevrolet
Model: S10
Engine Size: 6cyl
Refrigerant Type: 134a

After finding the orifice tube clogged with black gunk I removed the lines, flushed each line, the evaporator and the condenser. I then blew out the lines until no solvent was coming out. I replaced the compressor ( with the proper amount and type of oil ), dryer and the orifice tube. Evacuated the system for 45 minutes, checked for leaks and charged the system. My readings were within the limits in the chart I have and I got a 52 degree drop in temperature at the closest duct to the evaporator. everything worked for a month and the the low pressure reading went very high (100) and I found the orifice tube clogged with the same gunk. I replaced the orifice tube after blowing everything out again, evacuated and charged the system and this time it worked for 3 weeks. Do I have junk in the condenser? When I flush and blow it out everything, including the flush fluid is clean on the exit. I must confess, as this is my friends truck I don't know what type of condenser is in this truck. If it is one of the parallel flow or other type of condenser that is very hard to flush out, could that be my problem. Should I remove it to flush it out or replace it?? Is this even my problem??

Matt L on Sat August 29, 2009 11:58 AM User is offline

Could be debris trapped in the condenser. I just replaced mine rather than even attempting to flush it.

TRB on Sat August 29, 2009 12:48 PM User is offlineView users profile

We have been getting a few flushing questions lately and while you can flush certain components! There is a procedure one must follow to achieve the proper results! Karl from Hecat explains the process in this tech paper listed in this link. We at AMA believe flushing using any other procedure will result in inadequate results and a component failure will result. If you can't follow this procedure the next option is new component replacement.

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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

HECAT on Sat August 29, 2009 7:29 PM User is offline

Understanding the complexity of the components (internal paths), the limits of many "so called" flushing methods (poof), the junk chemicals being offered (that don't come out), and how to test before reassembly (confirmation); are just a few things that you need to know for flushing success. Obviously it appears your problem lies somewhere in missing one or more of such key points.

Yes you have junk in the condenser, but by the condition of the OT; it has contaminated the entire system (again), and all the remaining oil is once again suspect. By chance did this thing get some sealer dumped in it before your major repair?

Oil flush the compressor (instruction on "Automotive A/C Procedures" page); maybe it can be saved. Replace the OT and Accumulator again, and also the condenser if you cannot properly flush. Flush both evaps individually without OT or TXV in place, then flush the rear lines separately; and dry (dry some more). Follow the procedures over on the "Automotive Flushing Forum" page, to test and be sure you are satisfied (no guessing or assuming) that they are clean, dry, and good to go. Clean it properly or replace it; what other option is there?

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

TRB on Sat August 29, 2009 7:44 PM User is offlineView users profile

Quote
Originally posted by: HECAT
Clean it properly or replace it; what other option is there?

Do it over and over again until you have wasted enough parts that by process of elimination the system becomes clean. No where on the net or in a parts house has the flushing procedure been explained better than Hecat's tech paper. I challenge anyone to post a more accurate procedure for cleaning out an auto a/c system.



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When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

tps500 on Sun August 30, 2009 12:07 PM User is offline

Thanks HECAT,

I did what I thought was a thorough flush job following your tech article but apparently didn't get everything out of the condenser. The truck is used, so I can't say if someone put sealant in the thing. The junk on the OT is black and gummy while the oil still looks very clean with no debris. I will replace the dryer, OT and oil flush the compressor as you suggested and probably replace the condenser because it may have a sealer leaching out of it.

Again thanks for the help. I will let you know how it turns out.

Tim

HECAT on Sun August 30, 2009 5:29 PM User is offline

Tim,

If the OT is "black and gummy" again, with the oil appearing clean; then I would suspect that the flush process and the flush chemical used was not effective on removing the "gummy goo" from the condenser. I agree this condenser should be replaced as this may be semi-set sealer that will not ever be removed. Thank you for taking the time to, and confirming that you read the flushing article; I am sure this has helped you understand how challenging this can be.

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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

tps500 on Wed September 02, 2009 8:54 AM User is offline

HECAT,

After changing the condenser, and the lines (due to the muffler),flushing everything and servicing with oil and R134a to spec, I have at 85F, 225 high side 45 low side and 53F at the vent closest to the evaporator. These readings look good to me. Also, no debris from the compressor during the oil flush. Thanks for all your help.

Tim

iceman2555 on Wed September 02, 2009 6:44 PM User is offlineView users profile

I would be interested in the type flush chemical was first used.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

tps500 on Mon September 07, 2009 1:40 PM User is offline

I can't remember the kind of flush solvent I used the first time, but I do remember it leaving an oily residue on everything. I thought I had it all dried out but I am not sure now. The second and subsequent times I used Johnsen's and it dried very well.

I do have a new problem though. The compressor will not come on with the switch on the dryer hooked up. I have to jump that switch to get it to come on. The switch seems to work. It makes a click when I put it on the dryer and does the same thing when I take it off. I bent the pins just a little to make sure the connector was making contact. The pressures are high 220 low 45 with the ambient 85 and a vent temp of 53 at the closest vent the the evaporator. After shutting the ac off, I get both high and low readings of 90 and after an hour the are both steady at 110.

I am running out of ideas.

iceman2555 on Mon September 07, 2009 7:59 PM User is offlineView users profile

Johnsen flush is a major cause of this 'sludge' material. The chemical is very difficult to totally remove from the ac components. The residual chemicals break down the new lubricants and the result is quite catastrophic to the compressor and other components. If using this and many other chemicals, a very good air purge is necessary to insure complete evaporation of residual chemicals. Do not rely on evacuation to remove all residual flush chems.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

tps500 on Mon September 07, 2009 9:58 PM User is offline

What flush to use??

HECAT on Tue September 08, 2009 11:41 AM User is offline

Of course, I will recommend HECAT Safe-Flush.

This product is specifically designed to target PAG, POE, and Mineral oils. To somewhat oversimplify, it is a low odor, low VOC synthetic hydrocarbon base (petroleum distillate) with a small percentage of d-limonene (citrus distillate), which increases the solvency on the synthetic oils; without increasing the toxic fumes, flammability, and environmental hazards. Maintaining a balance between the cleaning task and the many other issues such as material compatibility, costs, haz-mat shipping, flammability, toxicity, etc.; is how we came to this formula. A 20-30 minute air blow is needed to evaporate this product down to the "negligible trace" level, which has proven with years of successful use; not to dilute the fresh oils.

There are faster evaporating products available but they bring many of these other issues along with them. Most of these products (such as the Heptane or NPR used in Johnsens products) usually have some required EPA and OSHA safety warnings and proper handling guidelines; and would probably require proper safety equipment and containment methods if used in larger volumes. This is usually somehow just skirted by under the smaller consumer packaging loopholes. Unfortunately, Some of the faster evaporating products just flash off too quickly; and leave behind the material we are trying to remove. There are also a lot of slower evaporating products (most commonly ester oil based); and you just cannot get them out.



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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

TRB on Tue September 08, 2009 12:21 PM User is offlineView users profile

HECAT - Safe Flush it's what we use in our shop.

-------------------------

When considering your next auto A/C purchase, please consider the site that supports you: ACkits.com
Contact: ACKits.com

iceman2555 on Tue September 08, 2009 2:19 PM User is offlineView users profile

The secret to removal of most flush chemicals is the after flush 'air purge'. This is often necessary to insure complete evaporation of various chemicals. It should be considered "SOP" after any flush is introduced into a system. All to often simple ambient temps and evacuation are thought to totally remove these residual chemicals, when in reality several oz of the flush chem may remain within the system.
Even the 'time tested' air popping may not sufficiently remove residual chems from the evap or condenser.
When 'air purging' insure that the air being used is clean and dry....use filtered air and a drier to insure that excessive moisture or contaminates may not be re introduced into the system.

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The strongest reason for the people to retain the right to keep and bear arms is, as a last resort, to protect themselves against tyranny in government.
Thomas Jefferson

HECAT on Tue September 08, 2009 4:37 PM User is offline


GREAT POINT!

Let the secret out! The "air purge" is MOST necessary!

Not only will several ounces remain if this is not done correctly, several ounces will remain even after the proper "air purge", if the right chemical is not chosen to begin with.

The 'time tested' air popping is a great way to test, but not effective at flushing or chemical removal.



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HECAT: www.hecatinc.com You support the Forum when you consider www.ackits.com for your a/c parts.

FLUSHING TECHNICAL PAPER vs2.pdf 

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