RV-12is Radiator Leak Advice and Info Pls.

[jackking123]

I went to look at friends RV-12iS and noticed "stain" on radiator, dark area. We had no plan to fly or time to dive deep into it, pull cowl at the time.
Did some research and see the Van's SL and all of that, but still not up to speed. My questions are:

If the radiator is leaking (yet to be determined TBD), what is the tell tale signs. I assume coolant on the ground after ground run? Pls advise.
(I see a dark stain area. This could just be oil or dirt, plan of cleaning the radiator first to remove any oil and dirt.)

If the radiator is cracked, it must be repaired or replaced. I read a new one is about $800 (although reading there are cheaper options apparently). Please advise.

Upgrade SL radiator and oil cooler is about $2500? Is that worth it and does that solve the problem. They attach heat exchangers to cowl? How does that work. Please advise.

Thanks in advance for the education.

 

[jsalley]

Hi Jack - I purchased the cowl-mounted coolers during my build, and have an unused original engine-mounted -12iS radiator still in the box that I’d be happy to part with for less than the Van’s cost. DM if your friend is interested.

 

[Amadeus]

If the radiator is leaking (yet to be determined TBD), what is the tell tale signs. I assume coolant on the ground after ground run?

From the front look where the bottom of the cooling fins attach to the radiator frame. If the radiator is leaking you will see drops of coolant near the corners at the bottom of the fins.

Some have been successful in repairing their leaking radiator. Since the leak originates at the bottom row of fins an opening can be cut on the side of the radiator and the bottom row of cooling lines can be blocked (I believe balsa wood was used, search for the thread here) then replace the opening material on the side of the radiator.

 

[N8DAV8R]

I have not had the leak myself so I don't know from experience but I would be looking for more than a dark spot on the radiator. By coincidence, it's easy to get some oil dripping in the same area when doing an oil change. I have been told by people with leaking radiator that they did have signs of dripping coolant on the floor.

 

[jrtens]

If the radiator is cracked, it must be repaired or replaced. I read a new one is about $800 (although reading there are cheaper options apparently). Please advise.

The replacement radiator is now $550.

RV-12iS Radiator, for kits shipped BEFORE 9/15/2025

Please note that this replacement radiator is only for RV-12iS aircraft kits shipped BEFORE 9/15/2025. Do not order for later kits or for aircraft that have been fitted with the updated radiator and oil cooler outlined in Service Letter 00112.

store.vansaircraft.com

You will also need the SB-00088 KIT if that has not been completed already.

SB-00088 KIT

SB-00088 KIT is the attachment method for installing the new .

store.vansaircraft.com

 

[jackking123]

Hi Jack - I purchased the cowl-mounted coolers during my build, and have an unused original engine-mounted -12iS radiator still in the box that I’d be happy to part with for less than the Van’s cost. DM if your friend is interested.

I am calling for a friends plane and I will PM you and exchange info. Thanks for the offer, that is great.

 

[jackking123]

From the front look where the bottom of the cooling fins attach to the radiator frame. If the radiator is leaking you will see drops of coolant near the corners at the bottom of the fins.

Some have been successful in repairing their leaking radiator. Since the leak originates at the bottom row of fins an opening can be cut on the side of the radiator and the bottom row of cooling lines can be blocked (I believe balsa wood was used, search for the thread here) then replace the opening material on the side of the radiator.

I have not had the leak myself so I don't know from experience but I would be looking for more than a dark spot on the radiator. By coincidence, it's easy to get some oil dripping in the same area when doing an oil change. I have been told by people with leaking radiator that they did have signs of dripping coolant on the floor.

The replacement radiator is now $550.

RV-12iS Radiator, for kits shipped BEFORE 9/15/2025

Please note that this replacement radiator is only for RV-12iS aircraft kits shipped BEFORE 9/15/2025. Do not order for later kits or for aircraft that have been fitted with the updated radiator and oil cooler outlined in Service Letter 00112.

store.vansaircraft.com

You will also need the SB-00088 KIT if that has not been completed already.

SB-00088 KIT

SB-00088 KIT is the attachment method for installing the new .

store.vansaircraft.com

Gentleman. Outstanding!!! Thank you. That is to the point and just the INFO I needed. Again thank you very much...

 

[jackking123]

Update so far it seems to be oil or something, not a leak...

 

[Amadeus]

The Dex coolant is a shade of orange.

The way the radiator is tilted you will get oil on it each time you change the oil filter and it, too, will be found on the bottom row of fins on the radiator frame.