Auto transmission fluid leak

[C250TD_1999_Auto]

Hi all, I have a 1999 C250TD Auto (Saloon) which I was cleaning last night when I noticed an oil leak from the front of the car (i had taken off the underbody cover). The leak was only present when the car was idling - when the engine was off no leak, when driving (reversing up the driveway, very slowly) resulted in no traceable leak on the driveway - having jackeded the car up i've taced the oil leak to a pipe thats under the radiator and runs down the side of the sump and goes to the auto transmission. It appears it comes from the auto transmission down the passsenger side of the engine to the radiator and then comes out at the bottom of the drivers side of the radiator. Therefore I am assuming it's a pipe that the auto transmission fluid travels down to cool the transmission fluid? The pipe is rather corroded which wont help. I've tried looking in the Haynes but no real joy on what the pipe would be? Question is am I right and is this a straight forward fix?? Assumption would be raditator out and replace the pipe around the radiator area (assuming this can be done?) - or should I just take it to a garage?

Attached are two pictures that show the pipe from beneath the car - one close up

 

[Cole@MBS]

Looks like its just a gearbox oil cooler pipe, shouldnt be to hard to replace,!

 

[television]

http://www.detali.ru/cat/oem_mb2.as...M=717.460&CT=GA&cat=23V&SID=27&SGR=230&SGN=12

All of the pipes can be changed, just keep the joints clean when changing, the correct the fluid level.

I would get an aerosol of engine cleaner and clean it down the you will see exactly where the leak is

 

[C250TD_1999_Auto]

ok, thanks guys - i'm assuming i'd need to remove the radiator and the fans first - but where would I buy the pipes? is this a merc only job? also - had a look at the diagrams (thanks for the link) - am i correct in thinking the pipes are not connected, my assumption was fluid would be circulated thru the pipes from one side of the gearbox to the other and be cooled as it travelled thru the pipe?

 

[Cole@MBS]

No need to remove the rad, all the pipes disconnect from under the car, one side is feed to the rad and the other side is return (cooled oil)!

 

[C250TD_1999_Auto]

Cheers fella - i'll have a closer look tonight - would i need to get the pipes from mercedes?

 

[television]

Yes, MB only parts

 

[Parrot of Doom]

I think you may find that the union on the radiator is corroded, and you'll have trouble sealing it. The pipes will be fine. At least that's what happened on my car.

There should be access ports to each pipe union at the radiator, you'll need to check to see which one the fluid is leaking from, and then check the condition of the radiator at that point. If its worn and corroded, you can rectify it by sanding it down (make sure you block the hole with a rag), but if cleaning it up doesn't work it'll be a new radiator.

 

[turbopete]

for wha its worth the oil cooler pipes corroded through on my car. replacements were about £50 for the pair.

 

[C250TD_1999_Auto]

Found it!

Well, I found the leak - a tiny pinhole! god knows how long that's been there (Ive only just got the car and last weekend was the drive from staines to Northants) - went to merc dealer today to get ATF - fixed the leak (it's not leaking now) but i'm gonna wait until tomorrow until I start her up and see what happens - if all is well and it holds (fingers crossed) i'll get the dip stick tool from merc next weekend and check the levels and top us as required. Am I correct in thinking I pour the ATF down the ATF level tube?

 

[C250TD_1999_Auto]

Bugger!

ok, does anyone know what I cud use to seal it? I've tried liquid metal were you mix two separate tubes put it on the pipe an leave to harden - but the fluid manages to squeeze past it at some point - tried three different versions of that stuff and no joy - i've now tried another product but the same is happening! Any suggestions greatly received

 

[Parrot of Doom]

Either sleeve it with rubber pipe and two jubilee clips, or just buy a new pipe.

 

[C250TD_1999_Auto]

finally!

well, I've managed to sort it (last night) bought some tape (http://www.halfords.com/webapp/wcs/..._productId_243317_langId_-1_categoryId_165691) and once covered I attached a jubilee clip over the tape where the hole is - compressing the clip to max stopped the leak in its tracks - left the car running for 20mins and still no leak! Merc now want £41.20 for the ATF dip stick tool so I can top it up!! still means I can drive it to Merc for new pipes without worrying - but that'll have to wait until pay day now!!!

thanks for the replies chaps -

 

[C250TD_1999_Auto]

update

went to merc and they wanted an hours labour to see where the leak was an then do a quote - hmmm - took the car home jacked up on axle stands, had a good look and stripped the wheel arch covers, under covers and then the bumper - the pipe going into the top was a little corroded in places so I decided it would need replacing too - might as well! anyway, got the pipes off (in radiator and out radiator) as well as the flexible return pipe which was stuck on! £112 quid later I had my three new pipes! had to remove the radiator (coolant needed changing anyway) - short is all back together no leaks, topped up with merc ATF and new coolant - saved a bit of wedge too! seems sweet but now I get an intermittent knocking noise - back on the stands then!