benzingtherules

Is there a separate part number for the elbow that is on the engine bay side?
I replaced the connector last year (thanks @Khan 55 but yesterday the elbow cracked.

BMWDR

And here we are in 2021 and this exact problem showed itself under the exact same circumstances! I love the torque these cars make and ran it pretty good through 2nd and 3rd gear and the coolant light comes on. As with most of the responses I was a half mile from home so no problem! Thank you for saving me a few hours looking for it!

benzingtherules

part# 2038300596
Its the elbow with hose.

Khan 55

Gentlemen I am afraid we cannot get this separately. My cousin called me last week to inform me that my coolant signal came up on the cluster. I don't recall ever seeing it mention coolant low. I hope my fitting didn't go out either. I was thinking of maybe getting a local one made if this is my issue again as my car is currently on 260 000km. I just replaced battery the other week. If this is the culprit for the coolant warning again, I will try and get an aluminum one made up locally but thats IF mine has failed.
Sorry for late responses gents as I don't always log on here.

benzingtherules

My previous post shows the image and part number for the 90° elbow on the engine bay side. I purchased the other day.

Khan 55

Thanks benzingtherules. I will save this for if and when I may need it again. As mentioned above, I seem to have some issue but since my car no longer stays with me, I can only get to it on weekends or after work.

Khan 55

Managed to have a look at it around this time and somehow my return hose or top radiator hose has ruptured. I have ordered the new hose and a new thermostat along with a new expansion cap to repair this issue but will also change the anti freeze as I did at the time of this above thread having been created.

BMWDR

My car is a 2004 CLK55 and has the washer tank heater that circulates through a coil in the washer tank. The part number for the inside the firewall hose and passthrough with the additional smaller connection is 2038300396-64. The motor to firewall hose with fitting is the same 2038300596.

icyjay

I have the exact same problem. Thanks for the pictures.

I usually buy parts from "pelicanparts.com". In this case, this website did not have any pics of these parts so it was a bit harder to find part numbers.

• 203-830-05-96: Heater Hose - Connection Point to Engine
• 203-830-03-96: Heater Hose - From Connection Tube to Heater Core

I also found the part numbers from Mercedes Dealer's part shop. See the picture blow. I am buying these parts to make it a weekend project. woot woot !
Do I really need to replace the water hose? I was planning to replace the hose fittings only cuz it it hard to disconnect one of the hose from the engine.
However, it seems like they sell fittings with water hose. What parts have you guys actually replaced?

Mountain_Benz

Renewed my membership here after a long absence with the same issue. 2002 CLK500 with 268,000 on the clock.

Exact same story.

Accelerating briskly from a standstill onto the motorway. *BANG*, "Check Coolant Level" message and the much coolant bleeding out from the firewall area down through the battery box to the ground. Stopped it safely in the emergency bay........ temp was still at 90 degrees C.

Towed home as there were no other options available.

Pulled out the covers, wipers, drain tray & windshield wiper assembly. The wiper assembly was loose on the LHS. Both the wiper assembly 13mm bolt and drainage tray T25 Torx screw were finger tight. So it seems the LHS of wiper assembly was rattling around gradually wearing away the plastic elbow. RHS bolts & T25 Torx were tight.

Indications of this have been going for years. There's been a small unwiped patch on the LHS windscreen. New wipers would fix it for a month or two but it would reappear.

So not sure if this a long term issue with body flex, wiper flex or the LHS wiper assembly screws not being Loctit-ed in, probably a bit of both. Anyway, I'll Loctite them in this time.I note later series C classes have support brackets from the firewall to the inner fenders to stiffen things up.

Unfortunately happened on a Friday evening so I'll have to wait until Monday for the MB parts dept to open.


Still on the firewall. Worn away by the windscreen wiper mechanism

Got the cursed thing out.

Close up of the wear

Mountain_Benz

Update: Got it out. Mongrel thing. Thanks @Khan 55 for an excellent guide.

I'll throw in a couple more protips!

*Wire clamp locking the coolant couplings pulls straight up.

*The couplings seemed very tight and one has to pull them out dead straight. Easier said than done. Any angled force will make them seem stuck. Wedged a large screwdriver underneath the motor side elbow and pushed the top of the elbow with my finger and voila! It popped off. This was after much swearing and just using the screwdriver from underneath, which would wedge the coolant coupling at an angle.

Khan 55

I am glad this write up is helping many of my fellow CLK owners.
Thanks for the tip Mountain Benz. Almost reminds me of when I changed my coolant pipe from engine to radiator hot side last year. Removed the spring clamp and I pulled my life's wit ends to get the hose off. Think due to all the years it never being touched just makes it harder for these things to come off. Glad your tip helped. Hopefully it helps other owners like us in the future.

I may have failed to mention or rather not done it at the time but I remember someone on this topic posted asking about the windshield scuttle panel. I do recall mine being flush with the windscreen. Since I removed it, up until today, I have a gap. I don't know if its due to the removal or was it because I left it to rest in the boot the whole time and with some heat it may have distorted a bit? Find it weird if so. None the less, I think once everyone conducts this repair, its best to apply a thin line of some sealer, maybe clear or the black sealer used for windscreen repairs just to ensure this panel sits flush against the windscreen. Having not done this, I now suffer with leaves and other dust getting under there. Will have to tackle this when I get down to conducting a "major" service on my car.

Khan 55

I am glad other owners with this issue have updated this post with their information, experiences and part numbers. Sadly as shown by Benzing the Rules above, both the plastic connectors are on separate hoses. Another post by Icyjay depicted above that there are two hoses for this. Each having a separate connector piece. I didn't replace my engine side 90' elbow and till today, Thank the Good Lord, I don't have any coolant issues.
I may have forgotten to mention, or perhaps not, but I see Benzing the Rules asked how to remove the "flange plate" that holds the connector in the mid section between engine and firewall or where the wiper arms and motor are located. That plastic plate has tabs that can be pushed inward or gently pry it with a tiny flat screw driver covered with tape to get it out as it needs to be used with the new hose and connection.
Regardless of this design flaw of Mercedez Benz, as mentioned above, getting aluminum or brass connections would put a worry like this to bed for many years. Then again ensuring coolant services are maintained and inspection every B or A service won't do harm and I am sure these plastic guys will be happy then for many miles again. Only failed on my vehicle at 240 000km - 250 000km for me.
Choice is yours gentlemen.

Thank you to all who updated this post with their experiences and part numbers as well as tips or ideas.

Mikeoxlodge

I just had this problem in my 2005 CLK500. Thank you all for your help on this post!

I had to cut out the old elbow on the engine side and I ordered both pieces from Mercedes.

I will post here if I have any questions once I start installing the new parts.

Mike