coolant system question
 

I realize that mercedes allows for a lot of temperature movement with these cooling system, both of my models move a bit, however the 108 has a recored radiator, big fat electric fan, new thermostat, new belts, and I don't like the way the gauge moves, it gets up there sometimes in the heat, do the water pumps go to **** on these regularly.

In my experience you replace the pump when it leaks or the bearing goes bad, both of which are external cues, will the impeller blades actually corrode and go to ****, if my gauge would stop moving around so much 60 odd for a new pump and an afternoon of turning wrenches seems like a steal.

Any thoughts?

Aftermarket water pumps tend to allow temps to go up more than than original water pumps because the clearance betwen the impellers isn't exactlythe same. I only use rebuilt pumps from the dealer. My cars are always rock solid right at about 82 or so. A bottle of WaterWetter might help to keep temperature fluctuations in check too somewhat.

Len

I had my ACC servro rebuilt, before I reintalled it. I back
 

flushed the heater core, recommended by the repair shop. The anti freeze is new. I replaced the ACC Servo and it works fine, but that was a week ago and I am topping off the tank every day, not much but it is down. I spoke tothe rebulided and he said this is OK, as both of you said these cars use a lot of anti freeze, and flushing the heatcore, took a lot out of the sytems. I did a very detailed checks for leaks and there are none. It is just a matter of letting the servo run and waiting until the engine cools down and top off until the sytem (heater core mostly) is filled again. I top off with distilled water. I also check the anti freeze protection temps every time I top off. It was warm enough yesterday, so the ambient temp allowed the AC to kick in, I turned the dial down to 65 degrees and I do have AC now. I was a little worried, when I got the servo back, it didn't thro a lot of heat, but now that the sytem is fillin with antifreeze and I bleed the system, losing some additional antifreeze, the temperature is getting warmer and warmer inside the car. Di you know tha Chrysler used the exact same Servo and system in the 70's for a couple of years?

Chrysler is the one that designed that monstrosity...in the late 60's Chrysler imperial. Their use predated Benz...

For a bit of history...

http://www.imperialclub.com/Repair/Air/

I think the engineer that designed that spent his final years in a mental ward....or at least should have.

coolant system question
 

Have you checked the operation of the temp sender and the guage?
Doug

Npw we know who to blame it on? the Imperial no
 

less, quite a high end car in its day! Thanks, good information to know

Funny...they would have never guessed they would become part of the same company in a million years back then.............

That's what makes life so interesting, also who
 

would have thought the Communism in Europe would fall, but in China is triving?

righteo, I'll look at the impeller blades once I get home and get it off. I can't think of how a temp sender/gauge unti would go bad, ie read to high a temp, I thought these were hard failure items, i.e. borken means no temp reading, couple of bucks for a used temp sender/gauge is fine,

thanks

Maybe you have air in the system. That happens whenever you open the system. I think that may account for temp extremes. One way to burp it is to park on a steep hill front end up, open the rad and slowly pour in coolant with the engine running. Don't open a hot rad. If that doesn't work there's a devise that gets air out, but I've never seen it nor know how it works.

After installing the repaired servo, I bled the system
 

as the instruction said and top off the antifreez, took two bleedings and top offs to finally get the anti freeze level stable. As I said my 450SLC takes a lot of anti freeze, especially the heater core.

Come to think of it maybe the 250S has a bleeder somewhere. Check the manual. If not and you bleed by the method I described you'll need a tube to fit in the rad filler to pour coolant into so you don't lose it. You should see bubbles come up if there was air in there.