Coolant Flush Notes -- De-Oiling Surprises - PeachParts Mercedes-Benz Forum

EricSilver · #1 09-10-2010, 12:01 AM

I am almost done with a long overdue coolant flush. I did the de-oil using Cascade Complete (dissolved three gel packs in a gallon of water and mixed with a gallon of plain water) then did another de-oil with Dawn detergent, in case the Cascade was too harsh. I am now on my third rinse and may do one more tomorrow before finishing with 50/50 Zerez/Distilled Water.

Made some interesting observations. Thsee are specific to the 95 E320 but may also apply to your car:

1. You do not need to drain the block if your car is on a forward incline. Coolant will flow forward from the block into the radiator. The 95 naturally E320 slopes towards the front, plus my carport is inclined. Each time I drained the coolant, 9 qts came out, the 10th presumably remaining in the heater core. The fluid which came out last (from the block) was much hotter than that which came out initially (from the radiator).

2. It is not necessary to drop the entire belly pan. Remove the front right (passenger side) screw and let that corner hang a bit. The coolant will flow along the channel in the belly pan into whatever low-profile collector you use to collect it.

3. Cascade Complete works MUCH better than Dawn or Tide as a de-oiler. I noticed this when I did the first flush. The Cascade effluent was cloudy beige and contained flakes of rusty scale. The Tide effluent looked like clean, sudsy water.

I noticed again after removing the expansion tank for cleaning – which was full of scummy, oily buildup (15 years worth as the tank had never been replaced).

I used Dawn initially, filling the tank and shaking it, then emptying it out. Not much came out. Then I dissolved one gel pack of Cascade, added some hot water and shook the tank. When I emptied it, a cloudy darker beige/rust water mixed with debris flowed out. Next I tried Tide. What came out was as clean as what I poured it. Finally, I tried a half-bottle of LA Awesome Cleaner (from the dollar store). It worked just as well as the Cascade, and was not sudsy like Dawn.

When I do it again, I will use Cascade Complete (3 gel packs per gal) or LA Awesome (About 1 Qt per gallon) because they actually do work, whereas Dawn and Tide, at least for me, did not.