Jump to content
Touring Motor Gliders Association (TMGA)

Rotax Coolant


algee1_73@yahoo.com

Recommended Posts

With 600 hours on my 912 the coolant is now just below the collar in the filler port.  This is the original coolant.

My thought was, why not drain the remaining coolant and refill with something new - my A&P recommends DEX Cool 50/50, which is readily available but a different color (and therefore I assume a different chemical basis).

Two concerns:

1.  Getting the inlet hose off the radiator so I can drain the system would not be an easy task, at least on my airplane.

2.  Depending on what you read and where,  mixing coolants is not a good idea.

Before I put more effort into it has anyone done this operation?  Or as another thought, anyone have experience mixing what came from the Czech Republic with something else?  Topping off the system with DEX 50/50 would take about 1/3 cup, and seem little different than draining the system, which will never get all of the current coolant out based on the geometry of how the radiator is mounted and where the hose inlet sits, and then refilling with DEX.  I'd think that would result in 1/3 of a cup of the original antifreeze remaining in the system, and the rest would then be Dex 50/50.

Jim??

Happy Holiday to you all.

Alan Gurevich/#24

 

Link to comment
Share on other sites

The Phoenix comes with Prestone Dexcool 50/50 prediluted.

A few simple rules of thumb from Rotax expert Roger Lee:

You can not mix a Dex Cool anti freeze with a non compatible Dex Cool anti freeze. It could thicken where it is not usable. Noted on some anti freeze containers is printed Dex Cool compatible. Still don't mix, but if you had a little residual when swapping coolant it shouldn't be an issue and for those engines that use Dex Cool type coolants it should be okay to use that coolant..
If you use Evans you only add or top off with Evans and absolutely no water as it is waterless.
If you use some of the other anti freeze products technically some could be mixed without adverse effects, but it isn't advisable.
You are always better served when using a 50/50 mix to always best top off with either distilled water or the same product that is in the cooling system. It doesn't matter if you use a standard time limited or extended life anti freeze because you should drain and refill every 2 years. It usually only takes approximately 2/3 gal.

Draining and refilling a Rotax cooling system is fairly easy and just takes about 15-20 minutes. No one should be penny pinching about spending $12-$15 for a gallon of coolant every couple of years.

Drain the Evans and while the system is open at a low point blow hard down through the coolant tank on top of the engine. That will just about clear the entire system out. Cover the low point with a rag. It can be messy otherwise. Dump the coolant reservoir. Then fill it up with what ever coolant you are going to use. It simple. It's a little more involved going the other way, but going back to 50/50 is easy. No purging of the coolant like the oil. just fill it up.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...