(coolant) Expansion tank plug kit--quick question - PeachParts Mercedes-Benz Forum

JBG · #1 07-18-2008, 02:12 PM

Got my new expansion tank and plug kit for the earlier models (I have an 85 w123 wagon). I can see how the plug and o-ring go in, but can't for the life of me figure out how to secure them in the hole with that ring-type thing that came with it. Can anyone help me out--how do you secure the plug? A pic or instructions would be awesome.

Thanks!!!

Chad300tdt · #2 07-18-2008, 02:24 PM

The ring holds the "wings" of the plug in the slot on the expansion tank:

johnathan1 · #3 07-18-2008, 02:41 PM

The circlip thing is kind of a PITA to install...

JBG · #4 07-18-2008, 03:48 PM

Great pic, thanks so much! I will undertake this operation once I get home tonight.....I can imagine it is not going to be super-easy, but then again, what is? (don't answer that...)

Chad300tdt · #5 07-18-2008, 03:54 PM

The job is super easy if you use a snap ring pliers like I did. If you don't have a pair, use two pairs of pliers and grab both side of the snap ring and pull apart as you slip it over the expansion tank neck while you have the expansion tank secured or held by a helper.

Snap Ring Pliers

JBG · #6 07-18-2008, 04:07 PM

Yes....jobs can become total nightmares or conversely total walks in the park depending on the TOOLS. And yes, I'm sorely lacking in that dept.

But I do think I have two pairs of pliers....we will find out. Thanks for the play-by-play Chad. You are a life saver.

EDIT:

SAVE YOURSELF A BIG HEADACHE/CHIPPED PLASTIC BY USING THE TOOL CHAD RECOMMENDS (SNAP RING PLIERS). Read on for my story.

Two pairs of pliers didn't really work--need the snap ring pliers. Went to Autozone, dude didn't know what to do, but sent me across the street to Meineke to a dude with a toolbox "bigger than your house" (his words). That was pretty accurate. The Meineke mech. said "it probably costs more than your house, too....did your house cost $150,000 dollars?" The toolbox was orange, about 7 feet tall and 5 feet wide (didn't see how deep it was). $150k for tools?!?!?! Wow. Needless to say, he had plenty of snap ring pliers and got the (expletive) circlip on there in about 2 minutes. I'm going to install it once the car cools for 3 hours or so.

In one of my weaker moments this morning, when it became obvious my tool selection was going to fail me yet again, I hurled some objects across the room

(no one was hurt, but I chipped a piece of plastic off the face of my stereo receiver. No big loss. I really need to deal with my frustrations more productively, though).

JBG · #7 07-19-2008, 07:56 PM

OK,

so I replaced the tank no problem, but when I disconnected the two coolant hoses that attach to the tank, I noticed they were still filled with green fluid. I had done a coolant flush about 2 months ago and gotten all the green stuff out, so I thought. Do these hoses not circulate coolant??? I had filled with quite a lot of Zerex G-05 and thought the green stuff was a thing of the past. Any reason green stuff would still be in those two hoses????

Confused,

OldPokey · #8 07-19-2008, 09:25 PM

I removed the thermostat and block plug and disconnected the monovalve. I flushed it all out pretty thoroughly with a garden hose - that got rid of all the ethylene glycol.

JBG · #9 07-20-2008, 11:32 AM

Pokey,

I removed the block plug and drained from the bottom of the radiator. Flushed with a garden hose that I attached right after the water pump. Lots of water came out of both places. Then I filled it with water and a cleaning agent, drove around to get it up to temp, repeated the flushing process, and filled with Zerex from the upper radiator hose and then gradually through the expansion tank.

My understanding was the coolant circulated through all the hoses. This doesn't seem to be the case in my car

Still confused,

Chad300tdt · #10 07-20-2008, 11:41 AM

Did you turn on the heater to circulate that stuff through?

JBG · #11 07-21-2008, 01:06 PM

Chad,

Yeah, I drove to a hill, turned on the heater, removed the cap on the expansion tank, and kept an eye on it for about a week (didn't need much more refilling that week).

That was about 2 months ago, tank has never been low on coolant in all that time, no need to check on things (so I thought).

Still confused,

turbobenz · #12 07-21-2008, 01:10 PM

I found that I had to flush it like 4-5 times with water to get it to run clear

JBG · #13 07-21-2008, 01:28 PM

Yeah, probably should've done that too, but wasn't up for it. Guess that's why I've still got green fluid! Thought a garden hose in the system running for like 5 minutes (two different times) would flush the whole thing out, but I suppose not. Oh well, now I've got green stuff, probably some rust/scale remover, and a bunch of Zerex in there.

This was one of those jobs that, in hindsight, would have been WAY worth it to have a mechanic do. Probably would have taken no more than 1 hour, could've used a machine to evacuate the old coolant, fill with cleaner, circulate, evac again, and fill with the good stuff. Probably would've cost less than $100. In my version of the job, I spent 5 or 6 hours and still (apparently) didn't flush out all the old stuff completely. I particularly enjoyed removing the engine block drain plug and getting showered with coolant/water the two times I removed it. FUN!

You know what they say about hindsight....

300SD81 · #14 07-21-2008, 02:47 PM

DIY snap ring pliers are pretty easy, all you need is:

old/cheap pair of pilers - i found some cheap chinese ones for $1
blowtorch or soldering gun
pipe solder + flux
small nails

simply solder the small nails to the pliers, only thing is you have to pull apart rather than squeeze when your using them.

I'm doing the same job now, its been 2 days and about 10 flushes, still got rust-colored water coming out. If you have ratchet extension of the proper length, its possible to crawl under, attach it, and remove the plug from the top, that way, you don't get showered with 80degC coolant.

JBG · #15 07-22-2008, 03:45 PM

Yes, anything is possible with the right tools.

Most of the time I don't have them, and don't plan to get them. Hence, my life is hard.

I'm much happier getting some help from someone with $150k worth of tools for 5 seconds than to buy a bunch of tools I might use 2 or 3 times total.

Thanks for the help,