Replacing radiator... anything else?

[300SD90]

Hey everyone,

I'm going to replace the radiator in my 81 300SD. Is there anything that you would recommend replacing while I'm in there?

I will be replacing:

Thermostat, upper and lower coolant hose (Uro Parts... ), Thermostat housing gasket, both cooler hoses, and of course the blue stuff .

I just wanted to see if anyone had found it easier to replace something while replacing the radiator. I just figured if there was, I might as well replace it now. Also, it looks like the previous owner was using conventional green antifreeze. Should I do a "citrus flush?"

Thanks!

[uberwasser]

How old is your water pump? It is only about $50 for a Graf brand pump. I think they are worth replacing every few hundred thousand miles as preventative maintenance.

You could also pull off and inspect your vacuum pump bearing, and check for play in the timing device behind it.

And I suppose if you have a front crank seal leak it would be easier to address with the radiator out.

None of the above are impossible by any means with the radiator in place, but since you asked, having it out would give you more working room.

[Stretch]

If you are not experiencing over heating trouble (you don't say why you are replacing the radiator) I wouldn't do a citrus flush - some people seem to get a bit carried away with citrus flushes (they can cause more trouble than they fix)

[cooljjay]

Agreed.....no flush! and no mention as to why you are replacing all this stuff? If your not experiencing any cooling issues, I would just flush everything out with the water house and refill with zerex G05..

[300SD90]

I am not having any cooling problems. The absolute only reason why I am replacing the radiator is because of the radiator neck failure. Pretty unfortunate, but it seems it happens to the best of us...

[vstech]

Be sure to comletely clean the ac condenser!

[300SD90]

Thanks for all the help! Any proven and effective methods on cleaning the condenser?

[NJ300sdl]

Consider using AC coil cleaner. Worked good on my home's evaporator.

[Skid Row Joe]

Originally Posted by 300SD90

Hey everyone,

I'm going to replace the radiator in my 81 300SD. Is there anything that you would recommend replacing while I'm in there?

I will be replacing:

Thermostat, upper and lower coolant hose (Uro Parts... ), Thermostat housing gasket, both cooler hoses, and of course the blue stuff .

I just wanted to see if anyone had found it easier to replace something while replacing the radiator. I just figured if there was, I might as well replace it now. Also, it looks like the previous owner was using conventional green antifreeze. Should I do a "citrus flush?"

Thanks!

While you're that close to the water pump, I'd replace it too, unless you know that it has been replaced in the last 50K miles or so.

[Skid Row Joe]

Originally Posted by uberwasser

How old is your water pump? It is only about $50 for a Graf brand pump. I think they are worth replacing every few hundred thousand miles as preventative maintenance.

You could also pull off and inspect your vacuum pump bearing, and check for play in the timing device behind it.

And I suppose if you have a front crank seal leak it would be easier to address with the radiator out.

None of the above are impossible by any means with the radiator in place, but since you asked, having it out would give you more working room.

Unless there's a reason not to buy a genuine OEM water pump from an MB dealer, why would you buy that one for 2.5 X more money??

I'd go with an OEM WP from the MB dealer.

Also, where do water pumps last a; "few hundred thousand miles," without showing signs of wear, in the first place?

[crazy4diesel]

Originally Posted by uberwasser

How old is your water pump? It is only about $50 for a Graf brand pump. I think they are worth replacing every few hundred thousand miles as preventative maintenance.

You could also pull off and inspect your vacuum pump bearing, and check for play in the timing device behind it.

And I suppose if you have a front crank seal leak it would be easier to address with the radiator out.

None of the above are impossible by any means with the radiator in place, but since you asked, having it out would give you more working room.

Can you please explain how to inspect the vacuum pump bearing and pay in the timing device behind it?

[uberwasser]

Originally Posted by Skid Row Joe

Unless there's a reason not to buy a genuine OEM water pump from an MB dealer, why would you buy that one for 2.5 X more money??

Sorry, confused. The Graf pump is 2.5x the price of an OEM pump???? Did you add a zero on that wasn't there? An OEM re-manufactured pump is $130-160 depending on where you look, or about 3 X the price of the Graf pump which is available for $43.50 right on this site... and which is brand new. I think you got it backwards.

Graf is a very reputable manufacturer that makes pumps that are often better than OEM. I'm familiar with them from the BMW side of things. It's not like I was suggesting a URO or Meyle pump.

As to your second question, I was not being specific in my mileage, obviously.

Either way, I'm not saying your pump WILL necessarily last you that long, but if it HAS lasted that long (as far as you know, i.e. you have no record of it being done) then it's good preventative maintenance to replace it for the whopping sum of $43.50 for a quality Graf pump.

Anecdotal evidence, however, shows that they can and do last a long time. My 1985 300D didn't have its water pump replaced until 150,000 miles. And my 1979 still had its original pump at 150,000 indicated miles but likely higher (slow odometer when purchased). I replaced it as preventative maintenance, which is all I was suggesting. It was not bad to the point of needing to be replaced, but while the system is drained and the radiator is out it's not much more work. Which is exactly what he was asking about.

[Hit Man X]

How are the hose clamps? Heater system hoses related to aux water pump/monovalve, etc.

[uberwasser]

Originally Posted by crazy4diesel

Can you please explain how to inspect the vacuum pump bearing and pay in the timing device behind it?

You'd inspect the bearing and roller surface for obvious signs of wear visually, and for freedom of movement. You'd also check that the bearing cage is intact, and that the ball bearings are properly held in/spaced out by the cage.

You'd also inspect the surface of the cam plate for excess wear.

And finally, you'd pull/push in and out, left and right on the nut on the end of the timing device (visible when the pump is removed, right in the center of the cam plate). Anything but the slightest play can indicate the brass bushing that the shaft rides in is worn excessively.

It might not be practical to address problems found during this inspection, but at least the issue would then be known and could be addressed when the car can be put up for work again.

[crazy4diesel]

Originally Posted by uberwasser

You'd inspect the bearing and roller surface for obvious signs of wear visually, and for freedom of movement. You'd also check that the bearing cage is intact, and that the ball bearings are properly held in/spaced out by the cage.

You'd also inspect the surface of the cam plate for excess wear.

And finally, you'd pull/push in and out, left and right on the nut on the end of the timing device (visible when the pump is removed, right in the center of the cam plate). Anything but the slightest play can indicate the brass bushing that the shaft rides in is worn excessively.

It might not be practical to address problems found during this inspection, but at least the issue would then be known and could be addressed when the car can be put up for work again.

Got it. Thank you much. Sounds like something I should have done before reinstalling the engine last Sunday. I'd had it on a stand for about 4 months, and had the vacuum pump off...I did fiddle with things, just rub my fingers around them and move them, seemed pretty tight, but didn't know about the timing gear thing, and hope I didn't miss an opportunity there I'll regret.

To the OP about your thread, my limited knowledge is I'd pretty much replace anything that deals with water that might need it. Hoses, clamps, whatever you can think of where the coolant flows...once you drain it, you might as well not do that again for a while.