Thanks to all who listed suggestions regarding what other equipment to replace as long as I am replacing the radiator (on my '89 300TE). My question now is, I assume that I should flush the system after the radiator, hoses, thermostat and water pump are replaced. Am I right? What is the procedure for flushing? How much is the capacity for a refill? That is, how much antifreeze should I buy? Last point, the current antifreeze is not the MB antifreeze. I will be replacing with MB. And someone mentioned adding a bottle of Redline Wetting agent. Do others use this? It makes sense that it would help decrease air bubbles sticking to metal. Where can I buy it? Thanks!

You should only need one gallon of coolant. That mixed with clean (distilled??) water should yeild about a 40-45% coolant/H2O ratio.

If the system had other than MB coolant, and you plan on using the MB coolant now, be sure to flush the system multiple times. I've heard that mixing the two can result in solid participate that could clog up the system.

It is best to pre-mix the coolant and H2O. I usually have an empty coolant jug and I will pour 1/2 gallon of new coolant into the old jug, then top it off with water. Sahke to mix then start filling the system. Do the mix until all coolant is used then top up with straight water. A bottle of Water Wetter can't hurt either.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

Thanks. What flushing proceedure do you folks recommended to ensure a complete removal of prior coolant and any old junk?

The flushing procedure for the 91 M103 calls for 2 flushes with deoiler and 3 flushes with citric acid. I believe you can use diluted dishwashing soap as a deoiler. Citric acid is supposed to be used in a 100g/l solution. If you email me directly, I'll check the manual to be absolutely sure.

Flush with the engine thermstat out and the ACC set to defrost. Run the engine to 80C then allow it to cool to 50C before draining. Run straight water as a rinse between flushes.

Sixto
91 300SE
86 300SDL (due soon)
81 300SD (for sale cheap)

Do you do all of these flushes with distilled water to keep the minerals out?

__________________
D.H.

04 ML500
02 E430

Experience is something you don't get until just after you need it.

I'll have to check the manual on distilled water. I don't remember reading anything specific to water. I can't imagine tap water is harmful, but then I don't hold it in my mouth for 2 years.

I believe the cooling system takes 11-12 liters of coolant depending on the car.

Redline Water Wetter is good stuff. Redline recommends no more than 20% coolant when using Water Wetter. Most folks who write about it say they continue to use 40-50% coolant which by Redline's information makes Water Wetter ineffective. I've had a bottle of Water Wetter in my trunk for 6 months waiting for me to decide which way to go

Sixto
91 300SE
86 300SDL (due soon)
81 300SD (for sale cheap)

I guess I'm still a little confused. I assume that most if not all coolant will drain out as I swap the various parts. Am I then to leave the thermostat out, reattach the thermostat cover, completely fill the system with water and de-oiler, run 'til 80 degrees, let cool, refill with just water, heat, cool, refill to de-oil, heat, cool, refill with water, heat, cool, and so on with the acid wash? Isn't that ten fills before refilling with coolant/water? And what's the best way to achieve a complete evacuation at the end of each flush cycle so that the system is completely drained?

Pulling all the hoses, thermostat and whatnot will only drain a portion of the liquid. Once you have drained down that far, you have to drain the block. There are two block drains located on the side of the block, with the heat in the on position, opening those drains will purge most of the remainder of the coolant.

Each flush and drain requires the block drains be pulled too. This process can be very time consuming. Plan a full day just to do a coolant flush, unless if you have very tough skin on your forearms. Pulling the block drains while the engine is hot will produce burns.

__________________
Mike Tangas
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72

'02 CLK320 Cabriolet - wifey's mid-life crisis

2012 VW Jetta Sportwagon TDI...at least its a diesel

Non illegitemae carborundum.

FWIW, the M103 only has one drain plug. V8s have one on each side.

Sixto
91 300SE
86 300SDL (due soon)
81 300SD (for sale cheap)