Coolant flush questions, hopefully not too redundant - PeachParts Mercedes-Benz Forum

BodhiBenz1987 · #1 03-21-2010, 12:33 PM

Well, I just emerged from somewhat of a hibernation from wrenching (house-buying, work and snow kind of put the car stuff on the shelf), and I'm ready to get greasy and sooty again. I already took the driveshaft out of my 300D over the weekend which was extremely satisfying.

Now I'm ready to do a long-needed coolant flush on the 240D. It's been driving quite well all winter, but now that it's getting warm (hot, even) out, I need to make sure the car is properly cooled. And it's full of green stuff of unknown origin. I've got it up on ramps (not that easy to do with a stick, I felt) and have a couple questions. Yes, I have done a search, but still can't decide.
1-Should I just flush, or citrus flush. The car seems a definite candidate for a citrus flush because god knows what's in there and for how long it's been in there. But, I keep reading about people doing citrus flushes and getting leaks everywhere. I have a bottle of GUNK radiator cleaner. Should I just do the citrus flush and accept the fact that I may have to replace a few things? Or should I try a plain flush and see what comes out first?
2-Where and how do you dispose of old coolant? We have a couple stray cats living in our garage, and while they can be a pain in the butt sometimes, they're very sweet and I would feel just terrible if they got into the coolant. I'm afraid to spill any or leave it around. How do you get rid of it?
3-In the DieselGiant writeup, he uses a device to remove vacuum from the system, which I do not have. I know I found a thread here at one point that describes the old-fashioned way of "burping," but I can't find it again. Can someone run me through the burp process?
Any help appreciated. I have the Haynes manual, which is ... you know.

tangofox007 · #2 03-21-2010, 12:53 PM

In my opinion, the citrus flush should be avoided except in situations where rust and scale are known to be a significant problem.

BodhiBenz1987 · #3 03-21-2010, 12:58 PM

Quote:

Originally Posted by tangofox007

In my opinion, the citrus flush should be avoided except in situations where rust and scale are known to be a significant problem.

So if I drain it and the coolant looks clean, and nothing comes out with the water flush, could I consider rust and scale not a significant problem?

tangofox007 · #4 03-21-2010, 01:03 PM

I would use the off-the-shelf flush. If it fails to produce a significant volume of sediment and there is no secondary indication of a cooling problem, I would be happy to leave it at that.

BodhiBenz1987 · #5 03-21-2010, 01:09 PM

Quote:

Originally Posted by tangofox007

I would use the off-the-shelf flush. If it fails to produce a significant volume of sediment and there is no secondary indication of a cooling problem, I would be happy to leave it at that.

The GUNK? It does list citric acid as an ingredient ... is it just less harsh? It says water, citric acid, tetrasodium EDTA, potassium citrate and diethylene glycol butyl ether. I could also get a bottle of the Shout that dieselgiant uses instead.

buffa98 · #6 03-21-2010, 01:18 PM

Before dumping any type of flush in see what the coolant looks like coming out. If there is not a lot of particulates floating in it, I would flush until the water comes out clear and refill with proper coolant.

There is a way to draw a vacumn on the system using the overflow hose but for the life of me I cant remember the specifics.

As far as the disposal do you have a 5 gallon bucket? dump the old into that. The parts store around here take old coolant I would check around where you are at.

tangofox007 · #7 03-21-2010, 04:19 PM

Quote:

Originally Posted by BodhiBenz1987

The GUNK? It does list citric acid as an ingredient ... is it just less harsh? It says water, citric acid, tetrasodium EDTA, potassium citrate and diethylene glycol butyl ether.

What is the exact name of the Gunk product?

BodhiBenz1987 · #8 03-21-2010, 07:56 PM

Quote:

Originally Posted by tangofox007

What is the exact name of the Gunk product?

http://www.amazon.com/Super-Heavy-Duty-Radiator-Cleaner-32/dp/B000ABE942 Gunk Super Heavy Duty Radiator Cleaner. Looks like there are a few milder products I could try.

layback40 · #9 03-21-2010, 08:20 PM

unless you have fluid in your radiator that looks like mud or a problem with overheating, a simple water flush is all I would do. Anything containing any acid has the potential to hole your radiator especially if it has an alloy core.

BodhiBenz1987 · #10 03-21-2010, 08:35 PM

Thanks for the input guys. The coolant that came out of the radiator didn't look muddy or contaminated ... just green. I didn't get a chance to get the block bolt off before heading out to work .. will finish up tomorrow before I go to the dentist ...

raslaje · #11 03-21-2010, 08:53 PM

Quote:

Originally Posted by BodhiBenz1987

2-Where and how do you dispose of old coolant?

My city "dump" takes antifreeze. You have to leave the container there (Guess they don't trust people pouring stuff in their tank and I don't blame them.) Just do a search on your city recycling.
I have no idea where to dispose of old diesel oil as the city only takes conventional oil as does Autozone. If anyone knows please post.

tangofox007 · #12 03-21-2010, 09:15 PM

Quote:

Originally Posted by BodhiBenz1987

http://www.amazon.com/Super-Heavy-Duty-Radiator-Cleaner-32/dp/B000ABE942 Gunk Super Heavy Duty Radiator Cleaner.

I would not use that on a reasonably well-maintained system. Green antifreeze isn't a major issue per se, it just doesn't have as long of a service life as the "proper" HOAT formulation.

dieseldan44 · #13 03-22-2010, 09:25 AM

Please, please don't use the the citric acid flush on our old cars! Look under my username for more in depth discussion about it. Water is fine.

I toasted two radiators, a water pump, and created a ton of work for myself.

For burping: If you take the upper radiator hose off and fill that (fils the head), and then fill the radiator (or expansion tank on a 300D turbo), you don't need to burp neaery as much. I just put the car nose up on a hill, take the radiator cap off, and rev to 3k rpms a few times. Never a problem. And I have way more experience with flushing and filling than Id like :-)

leathermang · #14 03-22-2010, 10:59 AM

I am amazed at the lack of reference to the FACTUAL way to check to see if your current (pun) antifreeze is effective.... or doing damage to your cooling system.
hint: it is clearly spelled out in the FSM....

BodhiBenz1987 · #15 03-23-2010, 10:44 PM

Quote:

Originally Posted by leathermang

I am amazed at the lack of reference to the FACTUAL way to check to see if your current (pun) antifreeze is effective.... or doing damage to your cooling system.
hint: it is clearly spelled out in the FSM....

leathermang ... any chance you could describe it? I don't have the FSM for this car, and only have the chassi/body FSM for the 124. I didn't see it when searching, although I guess I could refine my search after work tonight.