PragB

Ended up with a pinhole leak in my radiator. Quoted 4 hour job at independent shop. Figured at that price I should just do it myself. I did a search and found a DIY, but not certain the DIY is for the C55 as well, seems just to be a generic w203 DIY. I was told by a friend that the front bumper has to be removed and from what I can tell the DIY doesn't mention this step. Can someone with some insight chime in, or that has a link to a C55 specific DIY share it. I would definitely appreciate it.

kbob999

I've done this on a C32 (basically the same as C55 radiator), and without a lift it takes about 4-6 hours.
You don't need to remove the front bumper, but it would make life easier to nestle the parts together (In my case - intercooler radiator, cooling radiator, oil cooler, etc.).

Hardest parts is removing the radiator from the car, which is very tight, and uses a plastic clip buried way down low to support the radiator. You can't see the clip, and can't figure out how to un-clip the radiator. Once you do it goes smoothly. Having the replacement radiator helps to see how it clips in place.

I removed the lower grill, and the top radiator support metal bracket to make it easy to work on and gain access. And the lower cover body tray of course.

Prepare to make a mess as you need to drain coolant, and disconnect the transmission cooler lines and get trans fluid everywhere.

Sorry I don't have a link to the DIY, and did not log my progress. Any W203 will be basically the same.

PragB

Thanks for the tips, appreciate it.

Do you by any chance remember how much ATF to have on hand to replace what is lost?

kbob999

If you plug ATF the lines coming from trans as soon as you pull them, you will only lose what is in the cooler, which is 8-12 ounces. Probably lost twice that much coolant from spills and what is left in the radiator.

insame1

Pulling the bumper is not hard. Also you have to remember that that from the front fenders forward you are basically working on a clk.

PragB

Thanks for all the tips, I'm going to tackle it this weekend.

kjb55

The bumper does not need to be removed. I don't remember the steps exactly - but it's a very straight forward job. Very little if any trans fluid is lost. Good thing is that you can top off the trans from the dipstick tube.

kjb55

Attached are the work instructions. C55s are 203.076. Bumper removed is for 203.065.