I had an interesting problem develop last week. My audi 100 (K reg) started
overheating & when I
examined the coolant in the overflow box it was a brown colour and the
texture of liquid mud.
Thinking it was rust from the radiator I flushed it all out & re-filled with
anti-freeze.
2 days later the auto started slipping & jerking so I checked the auto fluid
level to find the fluid was a brown liquid mud type substance and had gone
up by a cm on the dipstick.

You've gussed it, the auto-fluid is mixing with the radiator water - how?
Well, the auto fluid is cooled by running the pipes through the radiator,
and a small split has resulted in the mixing of the two.
I now need a new radiator & potentially a new auto-box: unless the box can
be cleaned of the liquid mud & got working again.

I beleive this is the design on all Audi's with auto transmisson - so watch
out it could be an expensive repair.
Audi main dealer quoted 2800 pounds for a new auto box - car is only worth
1500 pounds.
Anyone know if there is a flushing fluid for an auto-box which could clean
it out before new auto-fluid is put in?
Any guidance is appreciated
Mike

 

FYI: Just about all automatic transmissions use the same feature.

 

Mike C wrote:
> I had an interesting problem develop last week. My audi 100 (K reg) started
> overheating & when I
> examined the coolant in the overflow box it was a brown colour and the
> texture of liquid mud.
> Thinking it was rust from the radiator I flushed it all out & re-filled with
> anti-freeze.
> 2 days later the auto started slipping & jerking so I checked the auto fluid
> level to find the fluid was a brown liquid mud type substance and had gone
> up by a cm on the dipstick.
>
> You've gussed it, the auto-fluid is mixing with the radiator water - how?
> Well, the auto fluid is cooled by running the pipes through the radiator,
> and a small split has resulted in the mixing of the two.
> I now need a new radiator & potentially a new auto-box: unless the box can
> be cleaned of the liquid mud & got working again.
>
> I beleive this is the design on all Audi's with auto transmisson - so watch
> out it could be an expensive repair.
> Audi main dealer quoted 2800 pounds for a new auto box - car is only worth
> 1500 pounds.
> Anyone know if there is a flushing fluid for an auto-box which could clean
> it out before new auto-fluid is put in?
> Any guidance is appreciated
> Mike
>
>
>
I've read somwhere that there are water-soluble adhesives used in a lot
of autoboxes to glue the brake band friction surfaces to the bands
themselves. This means very bad news, I'm afraid.