ATF leak, W210 - PeachParts Mercedes-Benz Forum

Parrot of Doom · #1 05-17-2007, 01:40 PM

Well somewhere behind the front bumper I have an ATF leak. Presumably a pipe or the cooler.

Anyone done this job before? Is everything accessible from underneath, or does the bumper have to come off?

Any idea on prices for parts? Not that it matters, whatever is leaking will very likely have to be replaced!

vstech · #2 05-17-2007, 01:56 PM

up there my guess would be a hose.
it's flexible, and it could have gotten hit by something.
look it over well, you will find the leak.
John

TMAllison · #3 05-17-2007, 02:17 PM

Tom - Make sure you clean everyting really well before cracking open any lines...you dont want any grit inadvertently getting in that trans.

I think you will need to remove the front lower sound panel and the internal grill cover to get to all the lines AND the cooler.

F18 · #4 05-17-2007, 04:02 PM

Once you pull the front and center splash pans/sound panels off you will have a pretty good view of just about everything from underneath.......oil cooler lines, intercooler hoses est. I'd say leave the panels off until it drips on a piece of cardboard so you can isolate where the leak is originating from.

I have had all that stuff pulled apart at one time to replace the radiator on my 98 E300.

Good Luck!

Parrot of Doom · #5 05-17-2007, 06:36 PM

So the lines in there are rubberised? Cool, that makes them repairable

TMAllison · #6 05-17-2007, 06:47 PM

Most of the lines are going to be metal with metal fittings/connectors. Be careful cracking them open, they can be a bear to get sealed again.

F18 · #7 05-17-2007, 06:49 PM

Quote:

Originally Posted by Parrot of Doom

So the lines in there are rubberised? Cool, that makes them repairable

I think the ATF lines (if I remember correctly) start up front at the cooler as threaded screw on flexible steel lines then transition to black rubber lines toward the transmission.

Parrot of Doom · #8 05-18-2007, 07:13 AM

Found the leak. There are two pencil thin pipes running along the bottom of the radiator from flexible hoses, and they're clamped together at one point, before they head off separately to the bottom and the top of the main radiator.

For some reason, the dealer couldn't find the correct parts on his system. Hes going to phone me later once hes contacted their main office.

At the clamp, one or both is leaking. I presume its been rubbing for years, and has finally had enough.

Heres the front of the car, you can see the pipes running along, with the clamp and leak near the top:

And yes I will be taking care of all that rust at the same time, fortunately its surface rust, the paint is shot. I'll kill the rust and POR15 the lot.

Heres the clamp where I reckon the leak is - its certainly the wettest and dirtiest part of the area:

I'm pretty sure its at that clamp, theres no oil on the pipes once they run vertically up to the radiator, and nothing near the flexible hoses. Just at that clamp. The clamp doesn't look quite right to me anyway, for some reason the threaded end rubs against the chassis. I'm sure its not supposed to do that - perhaps its supposed to thread through the chassis on an eyelet, that for some reason is missing?

The undertray had caught this - does anyone know what it is?

Parrot of Doom · #9 05-22-2007, 12:21 PM

It was the bottom pipe, the smaller of the two. The fluid was weeping from the seal between the pipe and the radiator. Its a banjo bolt with 2 copper washers.

I replaced both pipes, might as well anyway, and put new copper washers on. The connections to the flexible hoses do not require seals.

The top pipe is accessed from the front of the radiator, pop the bonnet and look just underneath the air intake duct - theres a large circular plastic plug. Remove that plug and the bolt is visible. Its around 19-20mm (don't know exact size, I just found a socket that fit). You need a socket, can't do it with a spanner.

The bottom pipe is trickier to reach. In the pics above you can see the large rusty bit of metal - on the near end of that is a small bolt that holds the oil cooler in place. Remove that bolt and pull the oil cooler down (you'll have to force it down, its tight but it will come). This reveals the bolt for the bottom pipe.

Everything is tightened and back to as it should be (the design of the top pipe has changed slightly, it takes a better route to the radiator now). I'll wait to see if there are any more leaks before putting the undertrays back together.

F18 · #10 05-22-2007, 01:17 PM

Quote:

Originally Posted by Parrot of Doom

Everything is tightened and back to as it should be (the design of the top pipe has changed slightly, it takes a better route to the radiator now). I'll wait to see if there are any more leaks before putting the undertrays back together.

Sometimes our discriptive differences of the same thing from opposite sides of the Atlantic Pond make me laugh.... ie. undertrays or splash guards or sound panels....... bonnets or hoods!

Parrot of Doom · #11 05-25-2007, 12:23 PM

Fingers crossed its finally sorted. You can't get the 'face' off the radiator, the nut was as tight as a tight thing and I didn't want to risk breaking anything, so we cleaned it in-situ. We then found some copper washers with a built-in rubber inner that looked a good option. Fastened them together, took it for a drive, not a drop or hint of a leak.

Of course I won't know for certain until I check the car tomorrow morning, and look for drips.

Heres the connection:

Heres how you get to it - one bolt secures that cooler, remove the bolt and you can drag the cooler down out of the way. You can see the eyelet for the bolt.

Heres the connection exposed, you can see the poor surface. That was cleaned up with sandpaper to give a better seal (we blocked the pipe into the radiator, no debris got in).

New washers with banjo bolt:

All fastened up:

Oh and if you ever wondered what a 722.6 gearbox dipstick looked like, here it is:

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