Pictorial on how to change the coolant expansion tank. - PeachParts Mercedes-Benz Forum

Diesel Giant · #1 03-30-2006, 07:06 PM

I just finished up the pictorial on how to change the coolant expansion tank on the turbo diesel.

http://dieselgiant.com/mercedescoolantexpansiontank.htm

A quick easy project any one can do!

Enjoy.

Austin85 · #2 03-30-2006, 09:15 PM

That was a "cool" pictorial.
I will check mine in the AM.

btw: I heard you are putting together a pictorial on W123 Dash removal and pod replacement just in time for Spring!!!!!

H-townbenzoboy · #3 03-30-2006, 09:25 PM

Once again, an excellent pictorial by the giant. That's almost too easy to do.

pawoSD · #4 03-30-2006, 09:49 PM

I think I may do mine sometime soon, whenever I fill mine up to the fill line, within a day its down below the seam.

Then it stays there indefinatley. Hmmmm, says I. Also, when I do it I am going to wire up a sensor too.

Then I can be fancy and have a low coolant light too.

pawoSD · #5 04-04-2006, 01:37 AM

Well, I just made a big order to Fastlane....In it are: new expansion tank, plug kit (cheaped out on the sensor idea...) some fuel filters, injector heat shields, some light bulbs, a rubber control arm stop-bumper, and thats it. Came to $100.00 even when I threw in a turn signal bulb (that I don't need) and so I get free shipping.

I determined that my expansion tank has a crack in it in almost the same exact spot as the one in dieselgiant's write up!

Explains why all my coolant "disappears" to below the seam level, then stays there.....

I'm also going to inspect my air cleaner assembly closer on wednesday....as I am paranoid about how well its sealed, and I think one of the mounts broke again.

I have 8 in my trunk, so I am prepared!

If I get too paranoid on the intake seals....dieselgiant may have an $18 order headed his way.....

pawoSD · #6 04-05-2006, 11:25 PM

Replaced my expansion tank today....did it a little differently, I unbolted the bolts....loosened the clamps for the hoses, pulled off the overflow and upper skinny coolant hose, lifted up the tank, pulled off the lower hose, tossed the tank on the ground (yes, with the remaining coolant in it), attached the new tank to the lower hose, mounted it with the bolts, attached other hoses, added coolant, and was done.

Total time spent: ~25 mins, 18 of them were trying to get that stupid plug into the sensor hole on the new tank...

Drove it around to operating temp, all is non-leaking and operating correctly.

Then I took apart half of my interior, and my light bars, to rig up a switch on my lower dash which allows me to turn on my reverse lights manually, since they don't come on from the shifter switch anymore (never have), works great! At least now I can turn them on when I need to....very easy, I just click the switch when backing up, then click it again when I shift back to drive.

It may not be 'the best solution' but it only cost me about $3.60 to implement. The whole process took almost 3 hours though.....

Tom Valdriz · #7 04-06-2006, 12:19 AM

Well done, Diesel Giant, very well done!

Tom Valdriz

Diesel Giant · #8 04-06-2006, 05:25 PM

Thank you very much!

DeltaDave · #9 02-26-2007, 11:45 AM

What is size of the upper hose that runs from the expansion tank to the radiator on a 1985TD ? The Fastlane seems to show a 8 x 15 mm but I'm not so sure .

tarbe · #10 02-26-2007, 12:43 PM

This reminds me, I am about due to place another order with Diesel Giant.

Thanks for all the great tutorials, etc on your website. A big help to MB diesel newcomers like myself. We appreciate you!

Tim

dannym · #11 02-26-2007, 01:13 PM

You had the green stuff in your radiator!!

JK, great job!!

Hey Pawosd, does the new tank hold a level above the seam now??

#12 02-26-2007, 10:50 PM

Wow, talk about a hard repair. Three bolts, two hose clamps and a slip on hose, I don't know how some people manage to complete such an extreme task!

pawoSD · #13 02-26-2007, 11:01 PM

Quote:

Originally Posted by dannym

You had the green stuff in your radiator!!

JK, great job!!

Hey Pawosd, does the new tank hold a level above the seam now??

I think so....but I don't have it filled that high...its about 1" below the seam....has been forever, it never changes....so everything must be fine.

Temps rarely even reach 83C...usually its around 79-80....

1985 300SD Sady · #14 02-26-2007, 11:23 PM

I would love to do this to my car... it really makes the engine compartment look great.

PawoSD, I know this is an older thread, but it sounds to me like your NSS is out of adjustment. Could be a really easy fix, or I guess it could be a bad NSS.

pawoSD · #15 02-26-2007, 11:38 PM

NSS?

My car has been running at 80-81C when its fully warmed up around the city....83C on the highway, and it runs dead-on at 85C when its above 65F outside....never higher. With my old radiator it was 85C with low outside temps, and as high as 105C when it got into the 90's out....the inside of the old radiator (it was the original) was fine, the fins were damaged and filthy though, it was time to replace it before it failed randomly.