Oil leak from transmission banjo bolt

[mikembman]

Hi,
I'd be grateful of some advice. In the process of fixing my 2006 C180K for another problem I noticed there is oil leaking from one of the banjo bolts on the side of the transmission - the one about half way up on the driver's side so it looks like I need to replace the sealing washers. My question is, do I need to drain the transmission fluid first before I remove the banjo bolt - I've only just had the fluid the changed - or will I be able to change the washers without losing too much fluid?
Thanks,
mike

 

[Wighty]

Is the leak because you have just had the ATF oil changed and that banjo bolt was removed to drain the radiator and Torque converter ?
Maybe try just tightening slightly incase it wasn't done up correctly after the recent work .

 

[mikembman]

Is the leak because you have just had the ATF oil changed and that banjo bolt was removed to drain the radiator and Torque converter ?
Maybe try just tightening slightly incase it wasn't done up correctly after the recent work .

Hi Wighty, thanks for the reply. I tried tightening the bolt slightly but that seems to have made the leak worse so I'm thinking the bolt is going to have to come out and the sealing rings replaced.

 

[Wighty]

I'm not expert but I think you will be looking at a substantial amount of ATF loss , maybe up to 3L ??? Depending on how quick you are . It would be much easier on a ramp . Hopefully someone else who has done it will chime in soon .
If someone else disconnected it recently could they do it ?

 

[mikembman]

I'm not expert but I think you will be looking at a substantial amount of ATF loss , maybe up to 3L ??? Depending on how quick you are . It would be much easier on a ramp . Hopefully someone else who has done it will chime in soon .
If someone else disconnected it recently could they do it ?

You're probably right and I should take this up with the garage that did the fluid change.

 

[umblecumbuz]

I think you'll find that you will lose hardly any fluid if you undo the banjo and replace the two washers.
If you jack up the car on the banjo bolt side before undoing it, this will help to limit any losses.

 

[star]

No need to drain, I suspect the ally washer/s have corroded. No need to touch this one when doing a fluid change, so don't go in guns blazing to the garage, it may not be their fault. You will only loose a dribble from the pipe, just check level after.

 

[mikembman]

Thanks for the response star. I thought the garage may have undone the pipe as they did a full flush of the system. If I'll only lose a dribble it's no problem to sort it myself.

 

[Wighty]

Thanks for the response star. I thought the garage may have undone the pipe as they did a full flush of the system. If I'll only lose a dribble it's no problem to sort it myself.

Let us know how you get on , I'm interested because anything I ever undo looses 110% of anything in there in under a second , normally over me

 

[mikembman]

I'll prepare for a flood and hope for a dribble . Will let you know how I get on - it might be a few days now before I get round to this job.

 

[Wighty]

I'll prepare for a flood and hope for a dribble . Will let you know how I get on - it might be a few days now before I get round to this job.

That's how I plan when I'm having a few beers in light coloured trousers

 

[mikembman]

Finally got around to doing this little job and the result is that only a few drops of fluid were lost while replacing the sealing rings. If it's important I had the front wheels on ramps and the o/s rear jacked up for a bit more space. I'm not sure how conclusive this is since I can't tell how much fluid there is in the transmission. I bought a transmission dipstick off a well auction site but it seems impossible to tell when it is inserted the correct distance - I've either got next to no fluid or it's up to the max when the fluids hot when the car is cold!

 

[Wighty]

Good update thanks , the no fluid loss with the car jacked up was worth knowing .
With the dipstick , you need one with the 20 degree and 80 degree (cold/hot) markings to make life easier . I bourght one a couple of years ago from eBay that works a treat .
Is your dipstick 722.6 specific ?

 

[mikembman]

The description of the dipstick claims it is for 722.6 transmission although it is much longer than the dipstick tube. I thought the top of the plastic bit on the end was supposed to stop the dipstick being pushed in too far but I seem to be able to push it in so the fluid level is up to the top of the plastic bit!

 

[mikembman]

Did you buy the more common type with the flat plastic measuring strip on the end? I see there is another type with a round measuring end which looks sturdier although its got to get round the bends in the dipstick tube.

 

[Wighty]

The picture isn't that clear but you can clearly see the graduated marks that show the cold and hot readings , on the other side of the black plastic part there are some graduated readings and the ones that match the hot (80deg) readings show 10-12 .

 

[mikembman]

This looks like the one I bought. I'll have to have another go at taking a measurement. Should it be obvious when the dipstick is in as far as it should be?

 

[Wighty]

This looks like the one I bought. I'll have to have another go at taking a measurement. Should it be obvious when the dipstick is in as far as it should be?

Yes there is an obvious stop when it goes as far as it can . Remember measure it hot after 15-20 min drive , on the flat , engine running and in Park .

 

[mikembman]

Thanks. Will have another go when it stops raining.

 

[umblecumbuz]

The atf dipstick you're referring to is designed so that, when the measuring tip reaches the 'stop' point in the gearbox sump, there will still be a short length remaining above the fill tube. Don't confuse its use with the engine oil dipstick which has to sit firmly with its grip handle snug with the top of the tube.

Initially the dipstick is inserted in the tube and pushed down. After much of its length has been inserted a resistance will be felt. Push a little firmer and it will move down a further few inches and come to an obvious 'stop'. This is the point at which measurement should be taken.

Ideally, the fluid should be at operating temperature (15 minute run around the block), the car should be on level ground, the gear lever in 'Park', and the engine ticking over.

Although there are 'cold' level reading marks, these are not as accurate. One reason for this is that the normal operating temperature (as mentioned above) is a constant, whereas 'cold' trmperature is entirely dependant on the ambient temperature at the time, which is a variable. A difference of a few degrees can give a large variation on the dipstick readings.