1983 240D Coolant Flush - PeachParts Mercedes-Benz Forum

JEBalles · #1 10-04-2009, 03:02 PM

I know there are already a million threads on this topic, but I can't seem to get the jist. Can someone give me explicit, step by step instructions on what to do? I'm not doing citric flush, just getting all the green stuff out and replacing with g-05 and t-stat replace. There are three bolts it seems: radiator, engine block, and block heater bolts from what I read. Which ones do I remove? How do I properly "burp" the system? I was told to run the engine up to operating temp and let cool all the way down with radiator cap off.

snookwhaler · #2 10-04-2009, 06:30 PM

I followed the tutorial over @ Dgiant. The whole procedure went smooth as silk. I recommend doing what he says in regards to removing the hoses and flushing. After running the "Shout" through, lots of orange crap came out. Especially out of the heater core hoses.

I opted NOT to do the citrus flush. I also did a complete fresh water flush 2 times (removing the hoses and flushing with fresh water every time).

I did all the above with my old rad. Then replaced the rad. after the flush was complete.

The job was really easy but a little time consuming. It was a PITA to remove the hose down behind the oil filter and I had a hard time pulling the "block drain" without getting scalded with hot water. If you can get in the right position it is cake, just be careful.

I had no problem with "burping". If you have the problem you can put the car up on ramps or go for a quick drive and re-fill.

You are correct about filling and watching with the cap off. Just watch your engine temp. If the water/coolant starts to lift out... You waited too long.

280EZRider · #3 10-04-2009, 06:45 PM

If you follow the advice of MBZ, you don't need to remove the block plug or disconnect heater hoses: Open heater controls to full heat, drain the system at the radiator drain, remove the thermostat, close up the thermostat housing (2 o-rings to make a good seal during flushing), close the rad drain and fill the system. Let it get to op temp or close to it (about 2500 RPM) - this takes time as the thermostat is out - and continue running for 10 minutes. Drain, refill with engine running, and repeat the process. When finished, replace the thermostat with a new O-ring and fill system.

Burping is done by parking the car nose-high and removing rad cap.

JEBalles · #4 10-04-2009, 07:44 PM

Quote:

Originally Posted by 280EZRider

Burping is done by parking the car nose-high and removing rad cap.

With the engine running?

And I read that the big crap can't get out the radiator plug, only the block plug. I think I might follow the dieselgiant one, unless anyone gives me reason not to.

snookwhaler · #5 10-04-2009, 08:07 PM

Quote:

Originally Posted by 280EZRider

If you follow the advice of MBZ, you don't need to remove the block plug or disconnect heater hoses: Open heater controls to full heat, drain the system at the radiator drain, remove the thermostat, close up the thermostat housing (2 o-rings to make a good seal during flushing), close the rad drain and fill the system. Let it get to op temp or close to it (about 2500 RPM) - this takes time as the thermostat is out - and continue running for 10 minutes. Drain, refill with engine running, and repeat the process. When finished, replace the thermostat with a new O-ring and fill system.

I have to disagree with you..... I did it this way when I first bought mine and did not get any crud out. I actually thought all was well and moved on.

After driving the car a few months, the "expansion hose nipple" on the radiator broke off (common problem). Before I replaced the radiator I followed Dgiant's tutorial. I honestly could not believe all the crud that came out. I'm sure a lot of it had to do with using the pressure from the garden hose. It is worth doing.

Quote:

Originally Posted by JEBalles

With the engine running?

Yes... With the engine running.

tangofox007 · #6 10-04-2009, 09:06 PM

Quote:

Originally Posted by 280EZRider

If you follow the advice of MBZ, you don't need to remove the block plug...

Where did you find this official MBZ "advice?"

I don't have the 616 FSM, but the 617.95 FSM absolutely specifies that the crankcase plug should be removed. Doing so is incredibly beneficial.

Doesn't it seem a bit strange that MB install a drain plug and then recommend that it not be used?

JEBalles · #7 10-05-2009, 04:57 PM

Quote:

Originally Posted by snookwhaler

I followed the tutorial over @ Dgiant. The whole procedure went smooth as silk. I recommend doing what he says in regards to removing the hoses and flushing. After running the "Shout" through, lots of orange crap came out. Especially out of the heater core hoses.

I opted NOT to do the citrus flush. I also did a complete fresh water flush 2 times (removing the hoses and flushing with fresh water every time).

I did all the above with my old rad. Then replaced the rad. after the flush was complete.

The job was really easy but a little time consuming. It was a PITA to remove the hose down behind the oil filter and I had a hard time pulling the "block drain" without getting scalded with hot water. If you can get in the right position it is cake, just be careful.

I had no problem with "burping". If you have the problem you can put the car up on ramps or go for a quick drive and re-fill.

You are correct about filling and watching with the cap off. Just watch your engine temp. If the water/coolant starts to lift out... You waited too long.

Why did you not do the citrus flush? I was advised not to do it unless I'm having cooling issues because it can take out the water pump and radiator. But you were replacing the radiator anyway.

Old300D · #8 10-05-2009, 05:42 PM

Quote:

Originally Posted by tangofox007

Where did you find this official MBZ "advice?"

I don't have the 616 FSM, but the 617.95 FSM absolutely specifies that the crankcase plug should be removed. Doing so is incredibly beneficial.

Doesn't it seem a bit strange that MB install a drain plug and then recommend that it not be used?

It is truly amazing how much crap comes out of that drain. Highly recommended.

JEBalles · #9 10-07-2009, 09:15 PM

Well I drained the green stuff and flushed it 6 times with fresh water, which seemed like a lot. The first couple times I forgot to turn on the heat though. Now, though, I've managed to lose the block bolt washer gasket in the engine compartment because I dropped the whole bolt when taking it out. Solutions?

tangofox007 · #10 10-08-2009, 10:17 AM

Quote:

Originally Posted by JEBalles

Now, though, I've managed to lose the block bolt washer gasket in the engine compartment because I dropped the whole bolt when taking it out. Solutions?

It is probably laying on the top of the crossmember. If you cannot find it, a 14 mm drain plug seal should be easy to find at the typical auto parts store. (Reusing an old seal is not a great idea in the first place.)

brownrice78 · #11 10-08-2009, 12:31 PM

I recently flushed the cooling system on my car and actually found no seal on the drain plug. I reinstalled it as it was. Hopefully, it won't leak but the odds are against me.

JEBalles · #12 10-08-2009, 03:26 PM

Alright, anyone else have input on this? Can I just put it in without one? Can I just get a replacement?