What's new
Van's Air Force

The definitive Van's Aircraft support community! Buying, building or flying an RV? Join our exclusive family of mentors and enthusiasts!

Leaking radiator troubles - RV-12iS

Fortunately it is a slow/small leak. I was able to continue flying for another six weeks with the leak. The new radiator arrived so I’m not sure how long I could’ve kept flying on the leaky one. Never an overheating problem and never lost much coolant. YMMV
 
fehdxl said:
Hi folks,

Is your RV-12iS radiator leaking? A little? A lot? Or totally dry?

We’ve been having an on-going issue with multiple radiators that’s pretty frustrating… just trying to see what’s going on with the rest of the community and see what fixes have been done and such.

Thanks. Fly safe!

-Jim
Click to expand...
RV-12iS, 223 hours. Major radiator leak in July of this year.. Ordered new one from Van’s, back ordered, due in Mid September☹️
 
Nov. 3rd. Still no new radiator for my RV-12iS. I’ve had my order in since July! Has anyone else received a new one?
 
Same problem here, I had the order confirmed in August 23rd... no news from them since then....
Quite annoying I would say....Terrible customer service!
 
Supposedly these radiators are holding up powerplant kit orders because Van's now refuses to ship incomplete kits. However, they continue to pump out S-LSA planes on a regular basis. It appears that they are prioritizing the factory built units.
 
Well, as a public service to help the grounded guys I can provide patched radiators that have epoxy repairs on the leaky spot. They may or may not be long-term fixes, but they will get you flying until the supply chain resumes. Send me a PM and we can discuss details.
 
I was notified today that my powerplant kit has shipped but without a radiator. I ordered the powerplant kit in May 2023. I’m very excited as this is the last kit I need to get my plane in the air.

When I asked when I should expect the radiator to ship so I can complete my build, they said the next shipment will be May 2025. 😑
 
Enzo said:
radiator leak repair

A friend of mine has an RV12 and has had 2 radiator failures. He's 87 and loves to fly, so I wanted to help him get back in the air. His newest radiator had a small pinhole leak on the lowest row of water tubes. It was coming from a spot where the tiny fins are attached to the tubes. The repair method I chose to use may not be long term. Only time in service will reveal if it's a good method to salvage an existing bad radiator. I cut out a small area of the outside of the tanks to gain access to the lowest water tubes. Once I had access I used a very small stainless steel wire brush to clean off the aluminum around the water tubes. After that I carved 2 small pieces of balsa wood to be inserted into the water tubes. The wood plug is slightly oversize. Balsa is soft and it's easily compressed using needle nose pliers. I squashed it to the size needed to fit into the water tube. The balsa expands once it's pushed into the tube to tightly fit the tube. I pushed the wood in about 1/8th inch below the end of the tube. I used regular overnight cure J B Weld epoxy to fill in those 2 water tubes and then built up a mound of epoxy over the 2 tubes to encapsulate them. By doing this on both ends of the radiator you prevent any water from going though those 2 lower tubes. After everything had cured for a minimum of 24 hours, I welded patches over the areas I had cut out. J B Weld is good for up to 550 degrees F. once fully cured. Do NOT use the Kwik Set J B Weld for this type of repair. It does not have the same tolerance for heat as the slow cure J B. When I did the welding, I did it in short increments and cooled the area immediately with a wet rag to keep the heat affected area below what would potentially damage the J B Weld epoxy. Once it cooled, I did more welding and repeated the procedure until everything was fully welded. My friend has only flown his RV twice since the repair, but so far it's OK. He flies at least 3 - 5 times per week. If it starts to leak again, I'll post something in this thread. He'll likely replace the radiator with the new improved version from Vans once they become available. For now, he's very pleased that he can fly again.
Cheers
Enzo
Click to expand...
How long did this fix last? I am about to attempt it, and am looking for guidance if it worked or not?
 
DanFrazer said:
Are there any differences with the new radiators vs. old? Or are the changes made as part of the SB the only differences?
Click to expand...
Yes the new radiator has the modifications called for in the applicable S/B. But, after installing the new radiator IAW the S/B I still have only a fingernails width of clearance between the cowling and radiator on the upper right side. This is the same place my old radiator had obviously been contacting the cowling. I’m now looking at my options.
 
Jarett.Locklear said:
How long did this fix last? I am about to attempt it, and am looking for guidance if it worked or not?
Click to expand...
My friends repaired radiator is still doing fine. He flies the plane at least 4 times per week, and sometimes more. He bought one of the new upgraded radiators, but it didn't come with the proper brackets, so he reinstalled the one I repaired for him and as of today he has no plans to put the new one back in as long as the repaired one keeps being trouble free. Based on our success, I'd suggest my repair method as being reliable and worth doing, especially if you can weld or you have a friend that can do the welding. I don't know what a welding shop would charge to weld the tank patches on. Once the tanks are opened to gain access to the leaking tube it's an easy process to block that tube or tubes on both ends to keep any water from flowing through it. The important thing is to use the slow cure high temp tolerant JB Weld and not the 5 minute cure version of the product. It's important to do the weld in small sections and to cool the area as you go to keep from overheating the epoxy.
Cheers
Enzo
 
I'm now a member of the leaking radiator club on my 912iS with 141 hrs.
I haven't done the SB and put it off because I was under the impression the cowl hitting the radiator was the culprit and I had added 1/16" more clearance than the KAI calls for. The day I noticed the leak was after a cold morning start and the engine sputtered a few seconds before it smoothed out. Maybe those vibrations caused the leak? I'll never know if I had done the SB if it would have prevented the leak, but for those putting it off I'd go ahead and do it.
I'm going to look into Enzo's fix while I wait for Van's to get them back in stock.
 
CessnaTPA said:
I'll never know if I had done the SB if it would have prevented the leak, but for those putting it off I'd go ahead and do it.
Click to expand...
Tony - congrats on 141 hrs! You're not letting dust accumulate on the surfaces.

My replacement radiator was the original design and I have chosen to not perform the SB. The vibration is the most likely culprit and performing the SB would apply twisting forces and vibration to the radiator possibly accelerating the the arrival of the leak. Most certainly this latest radiator will begin leaking but I will get the most flight hours out of it that I can. I will replace with the new radiator design when this occurs. Before purchasing the new design I will take the radiator to a shop (telling them it is from a lawn mower or a go-cart or something, anything but airplane) and see if it is repairable.

I do recommend dynamic balancing of the propeller to reduce vibration.
 
Amadeus said:
Tony - congrats on 141 hrs! You're not letting dust accumulate on the surfaces.

My replacement radiator was the original design and I have chosen to not perform the SB. The vibration is the most likely culprit and performing the SB would apply twisting forces and vibration to the radiator possibly accelerating the the arrival of the leak. Most certainly this latest radiator will begin leaking but I will get the most flight hours out of it that I can. I will replace with the new radiator design when this occurs. Before purchasing the new design I will take the radiator to a shop (telling them it is from a lawn mower or a go-cart or something, anything but airplane) and see if it is repairable.

I do recommend dynamic balancing of the propeller to reduce vibration.
Click to expand...
I had the prop balanced before 1st flight. It's interesting you feel the SB will do more harm than good, what do you base that on?
So is it confirmed there is a new and improved design in the works?
 
CessnaTPA said:
It's interesting you feel the SB will do more harm than good, what do you base that on?
Click to expand...
The SB involves cutting the radiator frame. This will involve clamping the radiator to a workbench (or wrapped in a rag and put in a vice) or some other method of holding it in place and taking a cutting tool to it. My thought is this would be quite a bit of vibration to complete the task. Could be the amount of vibration of one engine start and shut down or the vibration equivalent of 200 hours flight time, I don't know, but vibration none the less.

The new radiator design has a new frame/mounting design.
 
CessnaTPA said:
I'm now a member of the leaking radiator club on my 912iS with 141 hrs.
I haven't done the SB and put it off because I was under the impression the cowl hitting the radiator was the culprit and I had added 1/16" more clearance than the KAI calls for. The day I noticed the leak was after a cold morning start and the engine sputtered a few seconds before it smoothed out. Maybe those vibrations caused the leak? I'll never know if I had done the SB if it would have prevented the leak, but for those putting it off I'd go ahead and do it.
I'm going to look into Enzo's fix while I wait for Van's to get them back in stock.
Click to expand...
I followed Enzo's repair and feel confident it's going to work. Thanks for sharing your fix. 473155727_580134718234379_528058579220617694_n.jpg
 
As added insurance to mount the radiator more securely, we recently made and installed the aluminum angle brackets designed by CT Cole to my friends RV. The weld repair I did is still doing great, and hopefully it will work as well for others. This forum is a great place for everyone to share their solutions to this radiator problem.
Cheers
Enzo
 
We've ordered our PP kit in May 2023. It arrived in December 2024 without the radiator. Van's tells us they haven't found an "engineering solution" yet and don't know when the radiator will be shipped. I spoke to one of the main Rotax distributor in Europe and was told that this is a know issue with any radiator mounted directly to a Rotax engine. Apparently, there is enough twisting going on when revving the engine to damage the radiator. They recommended detaching the radiator from the engine and mounting it to the cowling (in a detachable way). Just leaving this here, maybe it helps someone who is further along in the build.
 
You must log in or register to reply here.
Back
Top