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|Automotive Refrigerant Leak Sealers FAQ
This article courtesy Cool Profits Magazine
This is an updated version of an article which first appeared in Cool
Profits Magazine. It has been reprinted here with permission from the
Dr. Jekyll or Mr. Hyde to the system?
I've watched the progress of this product after seeing it pop up on the bulletin board at www.aircondition.com.
Naturally, most of the first comments, from professional A/C
technicians, were non-complimentary at best. Then a few more
adventurous souls chose to test the product. Soon most everyone was at
least interested in the outcome. In the spirit of Fox News' very popular "fair and
balanced" reporting style: "we report, you decide."
To research this article we asked
several service techs to tell us what they wanted to know about A/C
system sealers. Those questions, along with a few of mine, were then
posed to the four manufacturers of the product that I could find. Their
answers are below.
1. How does your sealer actually seal an A/C system?
The Cryo Seal (or sealant) product reacts with air and moisture in the
air (humidity) to form a solid, polysiloxane (epoxy) seal at the site
of the leak.
From Cliplight Manufacturing:
Super Seal Pro™ is a blend of chemicals designed to seal leaks in both
the metal and rubber parts of an air conditioner. The chemicals contain
a formulation that is activated by extreme concentrations of moisture
to solidify and form a permanent patch. As refrigerant leaks out of the
system, moisture is created and activates the chemicals to self-seal.
Essentially, the extreme temperature differential at the leak point
causes condensation. This "moisture" activates the chemical.
A/C System Sealer is a two part moisture cure polymer that circulates
within the system as a liquid. At the point of a leak, the leaking
refrigerant creates a small amount of moisture because of the pressure
drop. That moisture causes the sealer to set and form a permanent seal.
From Technical Chemical:
Castrol/Johnsen's Leak Stop incorporates an active ingredient that
rejuvenates the seals, gaskets and o-rings in the A/C system.
2. Will it work with all (mobile) refrigerants?
Cliplight: Yes, except hermetically sealed compressors for which testing is underway.
Cryo-Chem: There are Cryo Kits for both R-12 and R-134a systems.
Keep-it-Kool: The Keep-it-Kool™ A/C System Sealer was developed and tested for use with R-12 and R-134a refrigerants.
Tech Chemical: Leak Stop is available for R-134a (#6536) and FREEZE 12 (#6002).
3. Will the material clog TXVs, FOTs, VOVs, Schraders, accumulators, driers or any other A/C components?
Cliplight: No, when the chemical blend is injected into the system, the drying agent removes any moisture present at the valve core.
The "SSR Kit" is composed of two components: a can of Tune Air and a
can of our Cryo Seal. The Tune Air chemical dryer reacts with moisture
and converts it into silicon oil, which is inert to the system.
Chemical drying achieves and maintains a zero parts per million
moisture level within the system. This is the best preventative
maintenance one can perform.
After replacing the
dryer/ accumulator, the Tune Air is added and the system is run for ten
minutes. Only then does one add the Cryo Seal.
No, the sealer will not clog or effect any other component of the a/c
system when installed according to manufacturer instructions.
Tech Chemical: No.
4. Will it harm any of the system components?
Cliplight: No. During the injection process, drying agents in the blend prevent any sealing activity.
Cryo-Chem: No, it will not harm any of the system components.
Tech Chemical: No.
5. Will it lessen the cooling performance of the system? (Increase system temps and pressures?)
Cryo-Chem: Just adding the Tune Air chemical will result in a 5 - 7° drop in duct temperature within 10 or less minutes of application.
Cliplight: It may improve cooling performance as it improves thermal efficiency.
All of our tests have indicated that there is no effect on the a/c
system’s performance or ability to cool. There were no noticeable
changes in pressures.
Tech Chemical: No.
6. What happens to the sealer while it is in the system?
The chemical formulation remains in the liquid state inside the a/c
until it detects moisture at a leak point and then self-seals. It does
not affect the lubrication ability of the system oil in any way.
Keep-it-Kool: The Sealer remains a liquid while in the system.
Tech Chemical: Nothing.
7. What types and sizes of leaks will it seal?
If the system is leaking slowly and holds a partial charge for at least
two weeks, Super Seal Pro will seal the leak. It will also seal most
medium sized leaks, where refrigerant is lost in less than two weeks.
However, if the hole is large and the refrigerant charge is lost within
24 hours, the system will need manual repair.
Because the chemical is reactive with moisture, it needs a completely
dry system prior to installation. Consequently, we require the
replacement of the receiver/dryer or accumulator, depending on system
The sealer is designed repair leaks in all
"stationary" metal system components (leaking compressor shaft seals
excluded). We also do not recommend using it on a known hose leak.
Accordingly, the first step to successful seal is to properly diagnose
the problem and use the product only when appropriate. The one time
when we do advocate its use on a potential hose leak is for the
nagging, two or three week leak that the technician can not locate. It
will be sealed despite the fact that replacement would have been the
preferred repair technique.
The system must be pulled into vacuum and after 10 minutes, be able to
hold at least 25" of vacuum for at least 5 minutes. This assures the
installer that the leak (or combination of leaks) is small enough for
the sealer to seal.
Typically, A/C system leaks will occur at mechanical joints (hose
connections, flange connections, mechanical seals, etc.). These are the
type of leaks that are sealed with Castrol/Johnsen's Leak Stop.
8. Will it seal multiple leaks?
There is enough material in a single application to seal multiple holes
in both the metal and rubber parts of the air conditioning system.
Keep-it-Kool: Yes. Each of the kits includes enough material to seal several leaks.
Tech Chemical : Yes.
9. How long will the sealer remain in the system? (Will it degrade performance as time goes on?)
Our sealer forms a permanent repair when it comes into contact with
moisture. If there are no leaks in the system, and therefore no
moisture, it will remain liquid with the lubricant in the system, ready
to seal any new leaks. It causes no degradation of performance.
Keep-it-Kool: The sealer will remain in the system until such time as the refrigerant is removed or recovered.
Tech Chemical: Indefinitely. The ingredients in Leak Stop will not degrade A/C system performance in any way.
10. What happens to the sealer if a line or component breaks catastrophically?
Cliplight: Along with refrigerant and lube oil, the Super Seal Pro material is blown out of the system.
We do not introduce significant amounts of the Cryo-Seal chemical into
the system in order to effectuate sealing. Much of the available active
material is used during the leak sealing process. Whatever is left is a
volatile (in that it readily vaporizes) chemical which tends to leave
the system when the refrigerant is discharged.
Keep-it-Kool: The sealer would be expelled from the system with the oil charge.
Tech Chemical: Some of the Leak Stop ingredient may be lost since it travels with the lubricant in the system.
11. What happens to a "sealed" refrigerant when it is recycled? Will it screw up a recycler?
The sealer will be removed from the a/c system with the refrigerant,
and then will be separated from the refrigerant with the reclaimed oil.
No effect on the refrigerant.
We are happy to report that we have not had a single reported incident
of a system being reopened later and residual Cryo-Seal causing
contamination of the system, regardless of whether it was flushed.
Keep-it-Kool: During refrigerant recovery or recycling, the sealer is removed with the oil.
Since Leak Stop travels with the lubricant in the A/C system, it is
recovered and discarded with oil. Even if the active ingredient in the
Leak Stop did make it all the way through the recycling unit, no damage
would occur to any of the components in the recovery/recycling system.
12. Where did this technology come from? Is anyone outside of auto a/c using it?
The sealant technology in Super Seal Pro has been used for decades in
the underground gas transfer industry, sealing leaks in pipes, tanks,
compressors, and other gas filled containers.
Tech Chemical: The active ingredient in Leak Stop has been around for some time; uncertain as to its applications in other industries.
13. Is your product flammable, or does it cause a non-flammable refrigerant to become flammable?
Cliplight: No, it has a very high flashpoint.
Cryo-Chem: Our products are non-flammable and will not effect flammability of a refrigerant.
Keep-it-Kool : From our tests, the sealer causes no effect on the refrigerant.
Tech Chemical: No.
14. Cost to the shop, or suggested retail price?
Cliplight: Super Seal Pro will sell for approximately $45 US and $70 CDN.
Keep-it-Kool: Suggested Retail: $64.95.
Tech Chemical: Suggested retail is $4.50 per 4 oz. can (single application).
15. Suggested applications? Should it just be used for Hail Mary repairs, or is this something that has a greater potential?
It allows the garages to keep their 'older car' business when expensive
parts replacement is not financially justifiable, ideal as a
maintenance (whatever the year of the car) and as a perfect complement
to our Retro Fit product for modifying R12 to R134a.
We encourage the technician to attempt to sell the part first, before
offering the sealer kit. When a customer is sticker-shocked into
declining the job, the kit offers a logical alternative. However, we
recommend that it always be offered as an alternative.
The sealer can provide an excellent alternative repair method. After
all, when a shop quotes the full job and the customer can not afford to
proceed, the shop is left without a sale and usually with any profit.
Using the sealer as an alternative repair allows the shop to proceed
with the job and make a profit.
After completing a large mechanical repair, a good practice would be to
install the sealer as a safety precaution. Countless times a system is
checked and the technician finds only one leak. Once that leak is
repaired and the system charged and operating at normal temperatures,
the next "weakest link" starts to leak. The customer complains that he
can't afford to proceed with the repair of the second leak, and would
not have proceeded to spend any money on the first repair if he knew
this would happen. Therefore, the service shop has an unsatisfied
16. Will it seal leaking compressor seals?
: It will not work as a sealer on shaft seals as the rotating shaft
pumps out material before it gets a chance to work its magic. It will
seal compressor body gasket leaks.
The sealer will not work on what we refer to as "moving" leaks. That is
leaks caused by compressor shaft seals or spring lock couplings that
generally leak because of vibration.
Leak Stop will rejuvenate the rubber seals typically found in
compressor shaft seals (rotating shaft seals) and/or compressor gaskets
to help seal any leaks.
17. Most importantly:
Will parts of the sealer solidify in the system (contact with
moisture), float around and eventually plug up a TXV or FOT?
No, the concentration of moisture in the system is too insignificant to
activate the product. (See 1, referring to extreme concentrations.)
There is a potential of the sealer attaching itself to a very wet
desiccant bag. Our instructions advise that on old systems that may not
have received ongoing service, a replacement accumulator or drier would
be an advantage. We have found no indication of any particulate causing
problems with the systems.
Tech Chemical: No.
18. If the desiccant
in the accumulator or drier is holding water, will the sealer combine
with that water, solidify, and then spread throughout the system?
Moisture in the dryer is not in enough of a concentrated form to
activate the sealer. After using our sealer, dryers have been cut open
in our lab and no evidence of any solids or product crystallization was
Cryo-Chem: Tune Air will
not restore a wet, saturated dryer. It's designed to remove the last
"free" moisture from the system and refrigerant oil. We require all
dryers/accumulators to be replaced before adding our kit.
Keep-it-Kool: See answer to 17.
We recommend Castrol/Johnsen's Leak Stop not only as a solution for
"phantom leaks" but also as a preventive maintenance measure to head
off potential leaks in the future.
19. Is an MSDS available for your product?
Cryo-Chem: Yes. Phone or written request.
Tech Chemical: Yes. Contact our Customer Service Dept. at (800) 527-0885 for details.
20. Suppose a system
has been treated with sealer but then is opened, and left open for a
few days, in a high humidity area. The refrigerant is recovered but not
all of the oil. Will the sealer that is in the remaining solidify
because of the humidity and become a problem when the system is
: No. High humidity in a fully open system will not cause the sealer to
activate. It takes a leak to generate the concentrated condensation.
Cryo-Chem: A wet dryer can deactivate the Cryo Seal and prevent it from ever reaching the leak site. See answer to #17.
Tech Chemical: No, it will not. Leak Stop rejuvenates the O-rings, seals and gaskets, it does not solidify in the A/C system.
Additional information submitted by the sealer vendors:
We've recently changed from a 2-step process (with separate
applications) to a single container application to increase efficiency.
Super Seal Pro is vacuum packed which requires the technician to vacuum
the system prior to installation. This ensures that the solution is
completely drawn into the a/c system quickly and effortlessly. We
believe that you cannot separate these steps, the 1-step process
assures a high level of success.
Additionally, ours has a beefed up drying agent and an increased dosage
of the ingredient that acts as a catalyst for the leak sealant
SSR/Cryo-Chem has been marketing specialty chemical products for mobile
air conditioning systems for over eighteen years. We have the advantage
of field experience that has shown us how they will perform, and how to
be successful in using and selling them to the public.
We are unique in the industry in that we offer a 1- year, unconditional
warranty. The technician fills out a registration card with the vehicle
type, age and mileage, as well as information about the servicing
location and technician. By comparing the data on the returned cards to
our known warranty rate, we have established a failure rate of 1 in 150
during our existence. Plus, we also learn why the product fails on
While the vast majority of failures are due to misapplication or
improper installation, we have experienced failures even with proper
installation. On these occasions, we found that were "running seam
cracks." Example: evaporator failure along the welded seam of the tank
and coil header.
As the product seals along the leading edge of the leak, that pressure
builds. The crack opens further, breaking off the seal. The only
indication of this type evaporator failure is that a system, which is
known to be leaking, holds vacuum for excessively long periods. Why?
Because the crack draws closed under vacuum (but won't hold pressure).
Thankfully, this type of leak is rare.
In the past several years, we have found that 1 of 6 cars reported are
Mercedes. These vehicles have a high rate of evaporator failure, and
about a 20+ labor-hour repair. Plus, removing the dashboard requires
disconnecting the air bag system and other vehicle control/monitoring
components. In this case, liability and comebacks tend to cause our Kit
repair to be offered before the component replacement. We believe this
situation with the Mercedes products to be indicative of the future of
our place in the automotive air conditioning industry.
Keep-it-Kool: Our Sealer was developed for professional use.
1) A UV dye is included in the Sealer in the event that a leak it too large to seal.
2) We use a proprietary installation hose kit that allows the
technician to: a) interrupt system without any loss of vacuum; b)
complete the installation without leaks, the risk of contamination, or
having the sealer set in the installation hose.
3) Our Sealer uses a proprietary patented packaging process that
assures a completely dry, airless container. This provides the longest
This is it for Part 1.
In the next article, we will hear from the technicians who have used
the product. If you are one of those techs, and would like to
contribute your findings, please email, call, write or fax
Cool Profits Magazine
Comment #1 (Posted by Beth T Knox)
very good information and extremely understandable
Comment #2 (Posted by Will Wilson)
Best site I've found on this subject. Thanks. You are Pros.
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