Please Help!!! Coolant Explosion!!! - Page 2 - PeachParts Mercedes-Benz Forum

chazola · #16 09-29-2004, 10:41 PM

I'd second that about the upper radiator hose neck, judging from the amount of coolant splattered in that area. How old is your radiator? These radiators are notorious for cracking and failing there.

lino · #17 09-29-2004, 11:10 PM

Quote:

Originally Posted by pberku

Since your coolant ended-up on top of the air cleaner, then here are some other things to check.

- Long hose betwen the radiator and the expansion coolant tank
- The nipple on the radiator to which the above hose connects
- Monovalve hoses
- Auxiliary water pump hoses
- Heater hoses
- Hoses leading to the heater inside the washer reservoir

More pictures if possible.

By the way, where do you live in Canada. I live in Montreal

Phil

Looks like tomorrow morning I'm going to have to inspect each and every hose very carefully.

Thank you

lino · #18 09-29-2004, 11:12 PM

Quote:

Originally Posted by chazola

I'd second that about the upper radiator hose neck, judging from the amount of coolant splattered in that area. How old is your radiator? These radiators are notorious for cracking and failing there.

Radiator is not that old and if the upper radiator hose neck is the top spout on the driver's side, mine is ok there.

lino · #19 09-29-2004, 11:15 PM

How much coolant will I need to buy to do a flush for my 1989 300ce?

Impala · #20 09-30-2004, 01:41 AM

I don't know how much coolant is needed to 'flush' the system.

But to 'fill' the system, the owner's manual for 1989 W124 says the cooling system capacity is 'approx 10.0 L (10.6 US qt)', with these numbers for the mixing ratio with water

Approx freeze protection: -30C / -22F
MB antifreeze: 4.50 L (4.8 US qt)

Approx freeze protection: -45C / -49F
MB antifreeze: 5.50 L (5.8 US qt)

lino · #21 09-30-2004, 02:57 AM

Quote:

Originally Posted by Impala

I don't know how much coolant is needed to 'flush' the system.

But to 'fill' the system, the owner's manual for 1989 W124 says the cooling system capacity is 'approx 10.0 L (10.6 US qt)', with these numbers for the mixing ratio with water

Approx freeze protection: -30C / -22F
MB antifreeze: 4.50 L (4.8 US qt)

Approx freeze protection: -45C / -49F
MB antifreeze: 5.50 L (5.8 US qt)

Thank You. I will probably have to buy some MB coolant to flush out the green stuff I just put in temporarily. Should I use regular tap water for mix?

mctwin2kman · #22 09-30-2004, 09:04 AM

Easy quick and dirty method to finding the issue is to fill the tank with water, since you do not need to waste coolant yet. Then run the engine and find the leak, but make sure to watch the coolant level and temp. On a cold engine you will not kill anything, but do not let it run forever. You should be able to find the leaking point in a matter of minutes. That coolant is sprayed all over due to the belts and other moving parts throwing it. So the leak is most likely the pump or somewhere near it, where coolant can leak directly onto the belt or pulleys. Could be a pin hole in the radiator as well spraying on the belts or pulleys. Best way to find it though is to top it off and run it for a few minutes til you spot the leak. Then fix the problem and refill.

lino · #23 09-30-2004, 12:16 PM

I squeezed the upper radiator hose and the coolant came out from the radiator plug. Here is what I mean:

This is the BEHR Mercedes radiator

This is the plug that goes from the upper radiator to the hose that connects to the overflow tank

Plug removed from radiator. This iswhere the coolant was coming out of and splashed onto the belt and made the mess.

Plug removed from radiator

Closeup of plug and it's broken

Another pic of the broken plug

Can this be repaired or do I need a new radiator?

donbryce · #24 09-30-2004, 12:49 PM

Glad you found the problem. If I may, I'd like to offer a couple of observations. The tank referred to as the 'overflow' or 'expansion' tank, to which this hose connects (# 6 I believe?) does not function, as I understand it, like a normal overflow tank, as in most cars with crossflow radiators.
The principle behind the tank in the MB design is to act as a pressurized resevoir for trapping air in the coolant. It's mounted so that the level line of the coolant in the tank is about the height of the top of the upper radiator tank. Notice that the filling of the system is from the bottom of the radiator and coolant passages in the engine (hose # 5). This method allows entrapped air to rise up and eventually end up in the top portion of the filling tank, which is under pressure.
The actual overflow, in case of over-expansion from excess pressure, would be out that hose you can see just under the cap. This hose is not under pressure, and from the picture (mine is an 85 380), your turns round and exits just in front of a grommet at the left rear of the tank. I'll bet that it droops down to allow coolant escaping after the cap releases to simply dribble on the ground.
I am only 99% sure of what I'm saying here, it's a longer story where the info came from, and I'd welcome correction if wrong. On my filling tank, though, there are only 2 connected hoses under pressure: #5, for filling, and #6, for air returning from the engine and radiator coolant.

Your picture shows a third hose, right on the top of the tank. Where does this go to? It's also not on the diagram (but then, you don't have a sensor on your tank either (#8), so the diagram doesn't match your car or mine.

That said, it appears you've got a broken plastic spigot thing that the hose fastens to. It looks like it just fits into the radiator tank socket? If so, should be a cheap piece.

lino · #25 09-30-2004, 12:49 PM

I just found out that the plug is sold separately by Mercedes and is called a Radiator fitting and the part number is 000 500 08 94. Price is $5.14 Canadian. Probably $2.99 USD.

Here is a pic of the original radiator that came on the car when it was new:

Here is the original part number:

Maybe someone can confirm this....My local Mercedes dealer says that the part number for the radiator above was replaced by this number:
A124 500 24 02. The original radiator may not have had the fitting that is broken on mine, which makes me think that I may have the newer radiator in my car. I don't have any pictures to verify. Does anyone know for sure?

Thank You

lino · #26 09-30-2004, 01:01 PM

Quote:

Originally Posted by donbryce

Glad you found the problem. If I may, I'd like to offer a couple of observations. The tank referred to as the 'overflow' or 'expansion' tank, to which this hose connects (# 6 I believe?) does not function, as I understand it, like a normal overflow tank, as in most cars with crossflow radiators.
The principle behind the tank in the MB design is to act as a pressurized resevoir for trapping air in the coolant. It's mounted so that the level line of the coolant in the tank is about the height of the top of the upper radiator tank. Notice that the filling of the system is from the bottom of the radiator and coolant passages in the engine (hose # 5). This method allows entrapped air to rise up and eventually end up in the top portion of the filling tank, which is under pressure.
The actual overflow, in case of over-expansion from excess pressure, would be out that hose you can see just under the cap. This hose is not under pressure, and from the picture (mine is an 85 380), your turns round and exits just in front of a grommet at the left rear of the tank. I'll bet that it droops down to allow coolant escaping after the cap releases to simply dribble on the ground.
I am only 99% sure of what I'm saying here, it's a longer story where the info came from, and I'd welcome correction if wrong. On my filling tank, though, there are only 2 connected hoses under pressure: #5, for filling, and #6, for air returning from the engine and radiator coolant.
Your picture shows a third hose, right on the top of the tank. Where does this go to? It's also not on the diagram (but then, you don't have a sensor on your tank either (#8), so the diagram doesn't match your car or mine.

That said, it appears you've got a broken plastic spigot that the hose grommet fastens to. I've seen repairs done very satisfactorily to upper necks using epoxy, so you might want to look into this to avoid the expense of a new radiator.

Thanks for the reply Don. On my W201 the neck snapped like in the picture below:

When I wanted to get it repaired, no radiator shop locally was able or willing to do it. I called a friend of mine from out of town and he had a radiator shop that he dealt with on a regular basis take a used radiator and replace the plastic tank with a new one and even offered a full warranty for a fraction of the price of a new radiator.

Regarding the diagram. That is from ************************. It was the only one I could find yesterday. You can see it clear here:

http://skinnerbox.steaky.org/Service/W124/w124CD1/Program/Engine/103/20-0100.pdf

donbryce · #27 09-30-2004, 01:24 PM

OK, so Mercedes actually calls this an 'expansion' tank, so I will too.

But I'm still wondering where that hose on the top center goes to, on your car, as it isn't shown on the skinnerbox pdf or on the diagram you posted?

MTI · #28 09-30-2004, 03:09 PM

The PDF shows that it's the "supply" (for lack of a better term) to the overflow tank. While it might be possible to reattach the fitting with epoxy, jbweld, etc., my experience has been that repairs to the plastic fittings of Behr and other MB radiators is that it's a short term fix. Plastic neck failures due to vibration/stress seems to be a common fault. I wish they still sold the metal sleeved radiators again.