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Coolant flush for 453?

5.7K views 10 replies 5 participants last post by  khlam  
#1 ·
Hey all,

Looking to change or flush the coolant for my 453. I'm aware Mercedes updated the recommended type, though I'm not sure I want to go for a full flush as it seems a bit far outside my skillset, so I'll be looking to mix with the stuff that came from the factory.

Has anyone found (or can make/explain) a good tutorial for doing this on a Smart? I'm not sure the more general ones apply. I've never done maintenance on a car before so I'd like to fully know what I'm doing here.

Thanks!
 
#3 ·
I think flushes only have value when a cooling system has been very poorly maintained. Drain at the various drain points and refill. If you change it on a regular interval the fluid you are leaving behind during a drain will not be damaging to the new. If you are concerned, run the new fluid for a few weeks and change again.
I use coolant test strips, they are made by WIX (part #24106). The strips are disposable, divided into 3 different reactive areas and tells you the level of Nitrate, PH & Glycol. When one or more of these reading starts to get close to the min I change coolant. That way what is left behind after a drain still has some life in it. I find I can go about 4 years before I see a change is in order. I check the coolant as part for the annual maint. If the stuff left behind were contaminating my new coolant it would show up on the next test as needing to be changed earlier.
As a side note, studies have shown that straight water cools engines better that coolant. In areas where freezing is not an issue it is not uncommon to run water with a rust inhibitor all year. Not recommending this, just say'n.... I use coolant in SoCal.
WIX Test strips
 
#4 ·
I think flushes only have value when a cooling system has been very poorly maintained. Drain at the various drain points and refill. If you change it on a regular interval the fluid you are leaving behind during a drain will not be damaging to the new. If you are concerned, run the new fluid for a few weeks and change again.
I use coolant test strips, they are made by WIX (part #24106). The strips are disposable, divided into 3 different reactive areas and tells you the level of Nitrate, PH & Glycol. When one or more of these reading starts to get close to the min I change coolant. That way what is left behind after a drain still has some life in it. I find I can go about 4 years before I see a change is in order. I check the coolant as part for the annual maint. If the stuff left behind were contaminating my new coolant it would show up on the next test as needing to be changed earlier.
As a side note, studies have shown that straight water cools engines better that coolant. In areas where freezing is not an issue it is not uncommon to run water with a rust inhibitor all year. Not recommending this, just say'n.... I use coolant in SoCal.
WIX Test strips
Good notes. Yeah, another part of why I don't want to flush is just because there's no real need.

Where are the drain points and how does one properly drain the coolant? That's the part I think I'm most confused with.

The only tutorial I found was by a guy who didn't look like he knew what he was doing. He essentially just let the coolant drain into his engine bay and onto the ground which seems extremely dangerous to me. I'm sure evilution has a tutorial, but anything close that I could find was locked behind a paywall.

Also, interesting about the water. Unfortunately where I am it gets sub-freezing a couple months out of the year.

I'm thinking I'll go to Home Depot or something and buy some hoses to attach to the drain so that I can drain the old coolant into a bottle to recycle or dispose of properly. hoping it's not too difficult to find something that works.
 
#11 ·
A while back, someone on this forum suggested this "no mess" method:
  1. warm up the car with reserve tank cap open
  2. pump out coolant, as much as you can, from the reserve tank
  3. fill up with water and let it circulate for a little while
  4. pump out from the reserve tank again
  5. refill with fresh coolant again
  6. repeat the about step 1-5 a few weeks later or as often as you like...