Radiator Replacement on W123? - PeachParts Mercedes-Benz Forum

jkoebel · #1 04-09-2008, 02:07 PM

How big of a job is it to replace the radiator on a W123, specifically my '83 240D?

I've got a new one which will be arriving soon, as a step in correcting some cooling problems I've been having. The fins on mine are pretty mashed in, and it's overall in dubious shape -- just waiting for a leak to start so I'm preemptively replacing it.

I can't find a guide on it anywhere...what concerns me the most is if I have to remove the oil cooler/oil cooler lines, I've read that they often get ruined, etc. Plus then I'll have oil leaking everywhere, etc etc...

Any advice that can be offered is appreciated.

Moorewr · #2 04-09-2008, 02:47 PM

I replaced my 77 300D radiator last spring, no trouble, drain at bottom, undo hoses, I took the oil cooler loose, just a couple of bolts, top/bottom, undid the shroud, and the 2 clips at the top, pulled it out, replace in reverse, not difficult, about 1 hour. When you fill it up, I put coolant in top hose and then attach to the radiator. Also have a bleed nut on top of thermostat, that I loosen, after start up to let the air push out. I would replace the thermostat while I had that much done, look at water pump, since you have the rad out and most of the tough work done.

I am not a certified mech and it was easy to do.

ron

LUVMBDiesels · #3 04-09-2008, 03:06 PM

Should be a drop in replacement. Remove the fan shroud by pulling the clips at the top. Undo the transmission cooler lines (if you have an automatic) Becareful not to damage the lines or the connector fittings. Remove the coolant hoses and give it a yank. It should just pull out. (on the 300SD W126 the radiator is not bolted in and I am assuming it is the same on a W123. Don't shoot me if I am wrong)

Put the new radiator in place and reverse the removal procedure. I would take the time to replace the radiator hoses and any drive belts that are worn. One hose to look out for on the 617 is the little one that runs from the thermostat housing to the waterpump. I am not sure if the 616 has this hose, but now is the time to replace it. I would also do the thermostat if it is old.

When you fill the system, fill it from the upper radiator hose until the block is full, then connect the hose and fill the rest of the way from the expansion tank.

Make sure you burp the system as well... put the car on an incline with the radiator higher than the rest of the car. turn the heat on to full hot and then gun it to 3000RPM a few times. This should get the air out of the system.

Good Luck!

JWJ · #4 04-09-2008, 04:20 PM

It's an easy job. I've even done it.