300TDT Transmission leak - PeachParts Mercedes-Benz Forum

dieseldaddy · #1 07-12-2002, 09:43 AM

1981 300TDT / 153K miles:
I noticed that I was leaking a considerable amount of tranny fluid and found that the trans cooler line connected on the passenger side of the oil pan had lost its rubber gasket and was crimped which caused the line to crack open. Now I need to replace it but I have a couple questions:

1. Where can I find this small section of line? I cannot find it on Fastlane, PerformanceProducts or anywhere else...didn't try the dealer yet...only if I have to.

2. Is the connection to the oil pan supposed to be "tight"? I can spin the allen screw and it doesn't seem to get tighter...This appears to be one of the scres holding the oil pan toghether or is its sole purpose to hold the trans cooler line?

3. I did a search and found one way to kinda "patch" the line...is this reccommended or should I just figure on replacing it?

4. I have a real hard time telling where my tranny fluid level is at! For some reason I cannot get a good reading from the dipstick. No matter how long I let it idle, I get strange readings, even when I KNOW it is full. (Just drained and replaced...) Dipstick looks like it is about 1/2" over the MAX line at the edges of the stick, but almost 1/2" below the MIN in the middle! What the heck?

5. What does it mean when I pull the dipstick out and there are bubbles at the very end of the stick but nowhere else?

Thanks in advance!
- Brian

leathermang · #2 07-12-2002, 10:53 AM

It means you have been petting the sweaty things..

or you need to be more specific about the "3. I did a search and found one way to kinda "patch" the line...is this
reccommended or should I just figure on replacing it?

before we can give an opinion of the reliability of the method....

dieseldaddy · #3 07-12-2002, 11:27 AM

leathermang,

Here is what I was referring to:

"The fix for that if you cant replace the line is take it loose at the cooler line and at the transmission. Clean inside of the line very well with carb or brake cleaner and air pressure. Expose rub in line and get a micro torch , some acid core solder and heat it up ,add the solder to the hole and wham back on the road. Use a small diameter rubber hose between it and the clamp so it wont happen again. ( Had to do this on side of road for a friend one day )"

Sorry. I just assumed that in addition to knowing everything there is to know about MB's, I assumed everyone around here reads minds as well!

Ken300D · #4 07-12-2002, 12:14 PM

Regarding item #4.

The fluid measurement is taken at the center of the stick. The side of the dipstick can show splashed fluid that is clinging to the side of the dipstick tube - also happens when you pour some fluid down the tube and then take a measurement.

So, the real measurement is the line at the lowest dry point on the stick - usually in the middle.

Ken300D

leathermang · #5 07-12-2002, 12:25 PM

I would never suggest using the solder itself to seal any hole which will be under pressure.. however you could do a close fitting patch with something like brass shim stock.. and sweat solder that to it... maybe use silver solder for important stuff... Greg

dieseldaddy · #6 07-13-2002, 11:17 PM

Thanks for the input!
I did some calling around here to find the steel cooler lines and got nothing. A couple places said to use rubber trans line or fuel line if I couldn't fine trans line.
So, I went to NAPA and bought a small section of rubber trans line and replaced the section of steel line (after very carefully using a pipe cutter as to not get any shavings or anything in the line) and double-clamped it at each end and I have NO leaks on my 300tdt!

Topped-off the tranny fluid and she is good to go.
Another DIY job for the books. (Before I got this car in February, the most DIY I ever did was change the oil on my motorcycle...sad but true.

)

Here she is so you know who you helped:

autozen · #7 07-15-2002, 04:27 PM

You may need to replace those rubber protectors that go around the line at the clamp on the other line. You could end up with the same problem. The part#
is 112-997-02-81.

Peter

dieseldaddy · #8 07-16-2002, 06:58 AM

Thanks Peter!
You know, I was so excited to actually locate the leak and repair it (I am relatively new to this DIY stuff) that I didn't even check the other side.

Your reminder is much appreciated!

-Brian