Mercedes-Benz W203 C-Class Radiator Hose Replacement

Описание

There are not a lot of radiator hoses on the Mercedes-Benz W203 and a fair amount of room to work on them, which makes inspecting and replacing them an easy DIY job. I recommend inspecting your rubber hoses every two years or so. As they age, they have a tendency to get hard and brittle. When you gently squeeze a hose, it should be relatively soft and easy to indent with your hand. It shouldn't feel like it is brittle or crunching when you squeeze it. It should spring back to its original shape pretty quickly after being compressed. If it feels very hard, then it might be time to replace it. If there is a bulge in the hose, or any type of crack in the surface of the hose, then you should replace it as well. Also check for leaks around where the hoses create their connections; that is a sign that the hose should be replaced.

To replace the hoses you will need to remove the two air inlet ducts and the front engine cover.

Remove each duct by compressing them towards the engine and slipping them off the air inlet.

With the ducts off, remove the front engine cover. It pulls up and away from the engine. The cover is held on by five clips and will easily come off with hand pressure.

Next, safely jack up and support your car. With the car safely off the ground, you will need to remove the engine tray. There are six 8mm bolts holding the tray on, the rear two also help hold the transmission tray. If you are going to leave the transmission tray on, remove the rear two bolts first, lower the engine tray, reattach the transmission tray bolts, then remove the remaining four bolts on the engine tray.

With the tray removed you will see radiator drain plug on the lower left front of the car. Place a catch bucket or tray under the plug and use a large flat head screw driver to open the drain plug.

The fluid will come out slowly at first so open the tank cap to break the vacuum and help speed things up. The fluid drains out a small spigot facing rearward and not through the red plug.

Remove the upper radiator to coolant pump hose. Mercedes-Benz uses quick disconnect attaching points where the hose meets the radiator, but sometimes the wire clip you need to pull out is facing something that does not allow it to be pulled straight out. If this is the case just unclip it from the radiator and then pull the hose out. You will need to reinstall it before reattaching the hose.

The other end of the hose is attached to the thermostat by a traditional hose clamp. Use a flat head screw driver, loosen the clamp and remove the hose. In the middle of this hose there is a smaller overflow hose that attaches and branches off to the reservoir. Use a flathead screwdriver and remove the clamp and hose from the reservoir.

Underneath the overflow hose is the auxiliary coolant pump. There is a hose that runs from the auxiliary coolant pump to the coolant pump on the engine, use a set of pliers and disconnect this hose from the auxiliary pump.

On the lower right part of the radiator remove the quick disconnect coolant hose, this hose is lower than the radiator drain plug so fluid will come out of it when you remove it, be prepared to catch and dispose of the fluid properly. This is also a quick disconnect fitting that is at an odd angle, I just unclipped it and separated the hose from the radiator. Remember to reinstall it before install the new hose.

There are two hoses that connect to the lower part of the coolant pump on the engine: one from the auxiliary coolant pump and one from the lower right radiator. Both are held on by traditional hose clamps, use a flat head screw driver and remove both clamps and hoses. You may have to run a small screw driver between the hose and pump to break the seal or if you are replacing them any way just cut them off.

Installation is the reverse of removal. Make sure you reset the quick disconnect clips before refilling the system with coolant.

Read the Full Article: https://www.pelicanparts.com/techarticles/Mercedes-W203/WATER-Replacing_Your_Radiator_Hoses/WATER-Replacing_Your_Radiator_Hoses.htm

Time: 2 hours
Tab: $100
Tools: Flat head screw driver, pliers,
Parts Required: New hoses
Hot Tip: Work on a cool car
Performance Gain: Proper operating temperature
Complementary Modification: Flush the radiator

Applicable Models:
Mercedes-Benz C230 (2006-07)
Mercedes-Benz C240 (2001-05)
Mercedes-Benz C280 (2006-07)
Mercedes-Benz C32 AMG (2002-04)
Mercedes-Benz C320 (2001-05)
Mercedes-Benz C350 (2006-07)