Plug your coolant overflow hose

[Philip]

According to Alta, the coolant overflow hose is no longer needed and can be plugged.

We validated that the cooling system can be pressurized, even on older models. Feel free to plug the overflow hose so it stops puking everywhere.
One less maintenance item!

I am reposting this and making it a sticky so that this info does not get lost. It will remain relevant for the 2018 and older bikes for quite some time.

 

[Josh402]

Okie dokie then.

 

[ElectroBraap]

Perfect!

 

[Alta_mxr]

You are correct. We validated that the cooling system can be pressurized, even on older models. Feel free to plug the overflow hose so it stops puking everywhere.
One less maintenance item!

So is there a coolant vent on the MxR?

 

[Philip]

My MXR looks to be already plugged up.

 

[Alta_mxr]

My MXR looks to be already plugged up.

So is there a plug visible by the fill port somewhere. I have checked the level a few times since new was down the first time the second time looked to be staying up.

 

[Philip]

2017 MX:


2018 MXR:

 

[Alta_mxr]

Your awesome Phillip. You will need to get the ExR so you can have the real differences shown for the good of the order

 

[Philip]

Your awesome Phillip. You will need to get the ExR so you can have the real differences shown for the good of the order

I agree 100%! Alta should give me an EXR and an SMR for a proper evaluation!

 

[Alta_mxr]

Exactly Someone needs to do a detailed analysis might as well be the forum admin

 

[OneLapper]

Does anyone happen to know the ID of the hose that needs the plug? Just being lazy, headed to the hardware store before I get to the bike.....

 

[Philip]

About 3-4 mm.

 

[Butch]

I guess I need to do this on MX19 and EX6...

 

[effinsiok]

I just finished plugging the cooling system on my 2017 MX and thought I'd share an easy way to do it.

First purchase an M6x1.0mm face seal plug McMaster-Carr.


Pinch the drain tube and remove the plug. Alternatively, you can buy a new one McMaster-Carr.




Remove the seat, the coolant fill port cover, and the deltawing. You can leave the deltawing wires connected and just rotate it off to the left side.


Pull the fill port up/back to get access to the overflow tube, pull the overflow tube out of the frame (it just slides out) and carefully work the fitting out.



Take the fitting you removed from the drain tube (or purchased new), and push it into the overflow port.


Remove the drain tube fitting with a 10mm wrench. I was able to twist an open-end wrench, but you could pull/cut the tube off the fitting and use a 10mm deep socket. With the overflow tube plugged I only lost a few drops of coolant with the drain open.



Clean around the drain hole and install the new M6x1.0mm face seal plug with a 7/16" socket (it's an aluminum plug, so don't go crazy on tightening it).