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RV-14A Oil Cooler Failure

graywoodworking

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My Airflow Systems 2006x oil cooler just sprang a leak after 80 flight hours. I'm hesitant to replace it with the same thing, as there are others who have posted problems with these coolers in the past. Can anyone recommend an oil cooler that is the same form and fit with the same performance?
 
My Airflow Systems 2006x oil cooler just sprang a leak after 80 flight hours. I'm hesitant to replace it with the same thing, as there are others who have posted problems with these coolers in the past. Can anyone recommend an oil cooler that is the same form and fit with the same performance?

I have an RV-14A with the A version of the IO-390 and I'm curious if you could share additional information about the failure. I have the same oil cooler with about 235 hours on it and no noticeable issues, but I have heard of some failures. Did you use the aluminum fittings that Vans supplied or did you use steel connections instead? What type of oil lines do you have installed (e.g., Teflon)? Was the failure catastrophic? Of course, pictures are always helpful too. Thanks much.
 
Where is it leaking from? Is it detectable?

I have had not so positive experience with Airflow system support, partly that their warranty starts from a date that was manufactured (not even sold) which I think it is ridiculous. They did replace my defective cooler which was under warranty and had never been installed but it took so arm twisting and time.

When I was looking to get a different cooler, SW has a model that has the same size/foot print and price was reasonable. I can't remember the model number.
 
I did use the aluminum fittings that Vans supplied in the FF kit. The failure appears to be between the fins, and not at the fitting. The rear cooling line is the original from the FF kit. The upper line is one that I purchased to clear the backup alternator, which is a little longer hose. I forget where I got it, but it is more flexible. Both lines were strain relieved to the engine mount with adel clamps. The failure came on during the last 6 hours of flight. I started to notice the smell of oil in the cabin during flight. The last flight left a streak of oil down the belly of the plane. When I removed the cowl there was oil all around the cooler, firewall, and scat tube. I was fortunate in that I was close to home and only lost about half quart of oil. Never lost oil pressure.
 
My Airflow Systems 2006x oil cooler just sprang a leak after 80 flight hours. I'm hesitant to replace it with the same thing, as there are others who have posted problems with these coolers in the past. Can anyone recommend an oil cooler that is the same form and fit with the same performance?

Just curious....have you had your prop dynamically balanced and if yes....what was your ips level before and after balancing? In my previous life I worked with large commercial transports and oil cooler leaks, especially split seams, were often tied to excessive vibration. I have about 180 hrs on my AFS 2006x cooler with no issues. I don't know if it has made a difference but early on I had my prop balanced to less than 0.05 ips.
 
My Airflow Systems 2006x oil cooler just sprang a leak after 80 flight hours. I'm hesitant to replace it with the same thing, as there are others who have posted problems with these coolers in the past. Can anyone recommend an oil cooler that is the same form and fit with the same performance?

Several -14A planes have had issues with oil cooler cracks; search for such in VAF and Facebook (RV-14 group). I, too, had two such failures in phase 1 testing. From the small, but noticeable, sample size of reported cracks they seem to be almost solely for the -14A models, several of which (but not all) have integral firesleeved hoses going to/from the cooler. Those hoses are more rigid, and with the engine/prop vibrations, might be transferring that add'l energy to the oil cooler. Note that The -14A has longer oil hose runs to the oil cooler than the -14, which might explain why the -14A is mostly affected.

For me, the solution was to adel clamp both hoses to the engine mount. Since I had two failures, my third and current oil cooler is now a certified one (Aero Classics Oil cooler 8000215 (20006A)). At the very least, although the instructions don't mention this, I would adel-clamp your oil hoses to the engine mount. BTW, the oil temp with the Aero Classics cooler is slightly higher than the Airflow Systems - maybe 5-8deg. My oil temps are now 185-190F, which is still just fine. EDIT - I see from your second post that you did use adel clamps; in that case, I'd try the new cooler.

_Alex
 
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The failure appears to be between the fins, and not at the fitting.

Never lost oil pressure.

Most of the oil cooler failures seem to have been at the fins, including my two failures. The second time, I was quite far away from home base, when I noticed the oil pressure slowly decreasing. I have since set very tight oil temp windows/alarms on my G3X, so that it will alarm if/when oil pressure drops in flight.

_Alex
 
Note that The -14A has longer oil hose runs to the oil cooler than the -14, which might explain why the -14A is mostly affected. Alex

Longer hose would flex more than short hose, so if anything, I would thing this is an advantage.
My first 14A now has round 300 hours and no failure.

It would be interesting to check the S/N of the coolers that have failed to see if they were made around the same time and if there was some production issue.
 
Very curious. My oil cooler failed at 82 hours with leaks in the fins. My prop was balanced and I used steel fittings. No further failure after 230+ additional hours.
 
I have the integrated fire seleeve Teflon hoses with steel connections on the cooler, but I have not secured the lines beyond the instruction specs. I also recently had my prop balanced from .39 IPS to less than .05 IPS, but most of the 235 hours were unbalanced. I haven't noticed any leaks yet, but I do keep an eye out based on the reports of failures. I didn't realize that the leaks have primarily been from the fins and not the connections.
 
SW 10611R

Can anyone recommend an oil cooler that is the same form and fit with the same performance?

Source a Stewart Warner/Southwind/Meggitt 10611R.

It's the original mfg. of heat exchangers, has solid, unfinned end tanks, and a much tighter intra-tank fin pitch (read: more surface area - more efficient).

Also of note is the AeroClassics "HE" Variant -- 8001649. It's similar in construction, dimensions as the 10611R and 20006X.
 
RE: Oil Cooler leaks. What is oil pressure at 75% power? At 100% power?

I bought a new Super Decathlon in 1993 and the factory had set the 75% power oil pressure at 90 psi. Needless to say, the 100% power oil pressure exceeded redline. I adjusted the oil pressure to 75 psi at 75% power which resulted in a 100% power oil pressure reading below red line.

Do not know what psi your oil cooler was tested. But the tested psi is probably short term vs the hours on your oil cooler.
 
I had adel clamps securing both oil cooler lines to the engine mount for strain relief. The leak was not at the tube fittings. It appears it was internal to the fins. I did have my prop balanced. It was initially 0.3 IPS and less less than 0.1 IPS after balancing. I had the balancing done at about 20 hours.
 
I had one fail at the fins with normal oil pressures and very good prop balance. I’m interested in alternatives too because at the price of an oil cooler Idont want to buy a third potential failure. I used steel fittings. I haven’t adel clamped the hoses to the mount it’s a good idea but done wrong could be worse. Hopefully cooler number two doesn’t yield!
 
Longer hose would flex more than short hose, so if anything, I would thing this is an advantage.
My first 14A now has round 300 hours and no failure.

It would be interesting to check the S/N of the coolers that have failed to see if they were made around the same time and if there was some production issue.

possibly (hose length); also the -14's oil cooler is mounted in a different way than on the -14A.

Regarding the production - when I contacted AirFlow, they said (at the time) that they had recently either changed vendors or their vendor changed manufacturers. Indeed, that could be a reason.
 
possibly (hose length); also the -14's oil cooler is mounted in a different way than on the -14A.

Regarding the production - when I contacted AirFlow, they said (at the time) that they had recently either changed vendors or their vendor changed manufacturers. Indeed, that could be a reason.

I think this is less likely that is as a result of mounting or hose size since it is all the reported failures are at the fin and both 14 and 14A are mounted on a airframe/engine mount and not on the engine which is subject to more vibration. Poor quality or a bad batch seem to be more plausible, especially that a failure of only at 80 hours.
 
Airflow Systems Oil Cooler Update

Source a Stewart Warner/Southwind/Meggitt 10611R.

It's the original mfg. of heat exchangers, has solid, unfinned end tanks, and a much tighter intra-tank fin pitch (read: more surface area - more efficient).

Also of note is the AeroClassics "HE" Variant -- 8001649. It's similar in construction, dimensions as the 10611R and 20006X.

Update: Pressure testing the cooler showed air bubbles escaping from a crack at the end of the first row of fins, on the opposite side of the inlet tube flange. It is possible I inadvertently damaged the cooler during the installation. Regardless, I no longer want a drawn cup style oil cooler in my airplane, as they are much too delicate. After talking with an Aero-Classics engineer about the possibilities and performance of a couple of coolers, I decided to order a 8001649. It was quite expensive, but I feel much better having a welded bar-and-plate oil cooler in my airplane. The engineer assured me this cooler will be as efficient, or better than the Airflow-Systems cooler, and it will be much more robust.
 
Update: Pressure testing the cooler showed air bubbles escaping from a crack at the end of the first row of fins, on the opposite side of the inlet tube flange. It is possible I inadvertently damaged the cooler during the installation. Regardless, I no longer want a drawn cup style oil cooler in my airplane, as they are much too delicate. After talking with an Aero-Classics engineer about the possibilities and performance of a couple of coolers, I decided to order a 8001649. It was quite expensive, but I feel much better having a welded bar-and-plate oil cooler in my airplane. The engineer assured me this cooler will be as efficient, or better than the Airflow-Systems cooler, and it will be much more robust.

Please let us know about the performance of your new cooler. The 14A certainly can use all the cooling in the oil system as they tend to run hot. I would appreciate a PM if possible once you have the results.
 
Please let us know about the performance of your new cooler. The 14A certainly can use all the cooling in the oil system as they tend to run hot. I would appreciate a PM if possible once you have the results.

I'll post results as soon as I get the new cooler installed and have a good test run.
 
Airflow systems has been mentioned a couple times, has Bill weighed in with anyone on this topic?

I spoke with Bill at Airflow Systems. He indicated that oil cooler failures were rare. Most of the failures he's seen were at the threaded fitting. I was disappointed in that they only warranty their coolers for one year after the date of manufacture.
 
Just to clarify my earlier comment here that my dissatisfaction with the Airflow system is mainly about their warranty just as stated by Larry as well.
My defective cooler which was brand new and had never been installed was replaced but I was lucky that it was within a year from the manufacture date.
 
I had an oil cooler failure at about 60 hours which left me stranded in Memphis, TN. Like others, it failed between the fins. Luckily I noticed dropping oil pressure when we were on final approach for a scheduled stop and no damage was done. Oil pressure never went below 60 PSI. I sent the oil cooler to Airflow Systems and it was replaced free of charge. The replacement now has 170 hours on it and no problems.
 

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Report each failure to Vans.

The largest purchaser of these oil coolers has all the power to effect change. That is Vans Aircraft. Giving Vans the data makes this a lot more clear and provides foundation for action.

Report hours on your engine,
Send a good resolution (sharp focus) photo of the failure region,

This is a safety issue and Vans has an excellent record of high attention to safety issues.

FWIW - I would get another brand cooler.
 
With this many failures and considering this is a critical/safety item, it would be really great if VANS or Airflow System provide some feedback. Were these part of a bad batch or random and possible manufacturing/design issue.
 
Larry,

Since you mention the fins pulling apart here is my two cents.

I had the same type of failure after 10 hrs with this model cooler.
Make sure there is sufficient slack and or looping in the hose to absorb vibration and any tugging on the cooler fitting. The brazed vanes will pull apart.

It may be as simple as re-clocking a fitting, or a fitting with a different angle.
 
Larry,

Since you mention the fins pulling apart here is my two cents.

I had the same type of failure after 10 hrs with this model cooler.
Make sure there is sufficient slack and or looping in the hose to absorb vibration and any tugging on the cooler fitting. The brazed vanes will pull apart.

It may be as simple as re-clocking a fitting, or a fitting with a different angle.

Some of the reported failures are at fin the opposite side of the hoses which indicates it is not the issue with the stiffness of the hose.
 
Survey posted to gather feedback

Today we emailed the below message to all owners of RV-14/14A aircraft that have been marked as flying status in our database. If you own a flying RV-14/14A and did not receive the email, it means we have likely not received a first flight report from you.

Hello RV-14/14A Owner,

We are writing to ask you to complete an information survey related to your flying RV-14/14. This survey collects data concerning installed oil coolers and potential leaking. A very small number of cooler leaks have been reported in the past, so we are working with the manufacturer to collect and provide data. We need responses from owners, regardless of whether you have had a leak or not. Note that there is no specific ongoing concern with the RV-14/14A oil cooler model, which was selected due to its high efficiency and reliability. Given the small number of reports, the oil cooler manufacturer is interested in reviewing any data available and has asked us to contact owners of flying aircraft.

If you own a flying RV-14 or RV-14A, please access the survey at this link and submit your information.

We appreciate your participation and support!​
 
I have 3 hours on my new Aero-Classics 8001649 oil cooler. I'm very pleased. Oil temperatures are running between 185 and 190 F at 65-75% power.
 
Vans Service Bulletin 00080

Vans posted a Service Bulletin on June 19th regarding the Airflow Systems 2006X oil coolers. The bulletin indicates there exists the potential for an oil leak due to a potential manufacturing defect.
 
SB-00080 "Inspection of EA-00002 Oil Cooler for Possible Leaks"

Link: https://www.vansaircraft.com/service-information-and-revisions/sb-00080/

"Advises owners to read the Airflow Systems service documentation, which directs inspection for possible leaks on a list of specific serial-number Airflow Systems 2006 X-Series oil coolers (Van’s part number EA-00002). Commonly installed as default equipment on the RV-14/14A but may have been installed on other RV models, as well."


Link to referenced Airflow Systems "Oil Cooler Service Bulletin 0001 – REV N/C"

 
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Link: https://www.vansaircraft.com/service-information-and-revisions/sb-00080/

"Advises owners to read the Airflow Systems service documentation, which directs inspection for possible leaks on a list of specific serial-number Airflow Systems 2006 X-Series oil coolers (Van’s part number EA-00002). Commonly installed as default equipment on the RV-14/14A but may have been installed on other RV models, as well."


Link to referenced Airflow Systems "Oil Cooler Service Bulletin 0001 – REV N/C"



Thanks for posting - this was quietly uploaded to Van's website and seems to not have been communicated by Van's to RV-14(A) owners as it should have been via email.

Unfortunately, the Airflow Systems Service Bulletin only lists a few serial numbers that were affected. I had 2 oil coolers that cracked in flight in the exact same place - one was listed in range of serial numbers in the SB; however, one starting with "D21-" was not. I had reported this to Van's, so it is unclear if I was one of the first to report a problem with the D21 serial numbers ... or, it was overlooked ... or ...
 
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