Well like most of the 722s, I have the typical slow leak. I lose about a quart a month, not huge but irritating.

It's not the drain plug or the pan/gasket there...

Can I assume it's probably the front or rear seal?

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Is it really leaking? If there is no evidence on the ground or underneath the car somewhere, it could be the diaphram (spelling?) in the vacuum modulator has ruptured & the vacuum line going to it is sucking the fluid into the car's system. I would say the worst place you would want it to leak is at the front pump/seal area. That requires trans removal. Paul.

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1984 300CD red/blk 290,000 partial resto
1980 240D 4 sp Brn/palomino gone
1997 Mazda Miata STO edition wife's baby
1988 Lincoln Mark VII LSC next resto
1986 Subaru GL wagon daily
1993 Isuzu pickup field beater
2008 Honda Civic EX-L 5sp wife's new car
1978 Honda XL350
1974 Honda XL70 my Calif. ride in HS

I have a similar leak and think it is from the front tranny seal. Classic symptom is that it leaks only after it sits for a while. From what I have read the torque converter sags when sitting and applies extra force to the bottom side of the front tranny seal thus creating a gap at the top side of the seal and thereby leaking slighly.

Fix requires pulling the tranny, so I'll live with it for now, and I'm contemplating building a small drip pan just for the tranny leak to stop the annoying spots on the dirveway.

Hope that helps.

BTW, why is it that we all drive on a parkway and park on a driveway??

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Stable Mates:
1987 300TD 310K mi (Hans)
2008 Jeep Grand Cherokee OM642 165k mi (Benzrokee)

Pretty sure the main leak on my '83 300D is the front seal in the transmission. Not going to worry too much about it, although it is playing heck with our new blacktop street. Old pavement was concrete, but this new blacktop is "better". Just trying to keep car running long enough for youngest to begin his driving life on it next fall. I figure it is slow and strong. He's probably gonna run into something so I'd rather he do it in this car. Going to be a race though. Rust is pretty bad. It may kill the car before kid can. Really a shame the transmission leaks since it really shifts and runs nice. Maybe before the kid starts driving, he and I will make a project of pulling the transmission and changing the seal. That would be good experience for him.

mine shifts like sh** and i am unsure as to where the leak is coming from, but there is definitely a lot lost.

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1980 240D, 197580 miles - "The Stuttgart Stomper"

The SDL leaks worse than the SD (others are inop ).

Didn't know the mod would allow for loss into the motor. Could I just pull the line from there and check it?

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

i'm actually thinking of going to the manual... if i can find one.

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1980 240D, 197580 miles - "The Stuttgart Stomper"

I know someone with a complete 240D setup, drop me a line.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

Possibly the o-ring on the bottom of the oil filler tube?

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Sam

84 300SD 350K+ miles ( Blue Belle )

after 125k mls these trans would leak from the front pump seal.[unless the fluid had been changed every 30k or so.it still requires pulling trans but it is not the shaft seal that you see once the torque converter is off.if you want to do it yourself hit man give me a call i'm not far away.214-9567007 david poole european performance dallas tx.

Hrm... I may as well replace that, can't hurt.

__________________
I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

My 1980 300D leaks at the banjo bold holding the oil cooler line.

Torqued it down according to spec with fresh washers on both sides of bolt.
Cleaned off and made sure no dirt particles.

I probably stayed under torque spec because it feels too tight.
Maybe need to go a little further.

Does not leak much.

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80 300D 340K Owned 30 yrs
83 300SD 440K Owned 9 yrs - Daily Driver 150mi/day
02 Z71 Suburban 117,000
15 Toyota Prius 2600 miles
00 Harley Sportster 24k
09 Yamaha R6
03 Ninja 250

Could the vacuum modulator be the source of a leak? I have a leak in that area. Im sure its not the banjo bolt to the cooler line. Its not the pan gasket either. I know there is an o-ring on the modulator. Could a bad o-ring be the cause of the leak. I still have the original modulator. there is an update for this, right? Tranny is 722.4.

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'85 300D Cal 280,000 miles
'14 GLK 350 60000 miles

used to leak from the drivers side cooling line that sat in the meal bracket.. cut out the offending section and put in some rubber fuel line.. its doing good for 2 months.. and a lil drip every now and then from the transmission lower bell housing.. its probably the front seal.... and i need to adjust the vac to the tranny.. it flares a tad bit.. i want crisp shifts.......... CRISPY