Water contaminated ATF - How to stop this?

[bv2991]

Greetings fellas,

It's been raining pretty heavy recently with the monsoon coming over here in Malaysia. 'Been driving in heavy rain, too.

Based on my experience last year, driving through deep puddles and standing water on road (plus a really serious wading!) water had got into my auto gearbox, contaminating the ATF. The 'box went bust and I replaced it with a used unit given the mileage on the original box was already about 200K kms.

So, after driving through heavy rain and spots of standing water (not that deep, probably 3 to 5 cm) I feared that the same might happen again. Sure enough, when I got home, pulled out the ATF dipstick and I could see some change in the ATF colour. See here:



Did the normal drain and refill (2.5 lit) today. Will probably repeat after a week (what you guys think?).

My only concern is: how could this happen? Is the car designed only to be driven on sunny days? Where could the water get in through? Here?


I suspect that the vent holes on the bellhousing may have let water in. Any solution to this problem? Help really appreciated!

[wheeler]

I wouldnt have thought the vent holes would let in water, if water could get into the oil through there then i would imagine you would get fluid coming out ?
What about the oil cooler ? its not allowing the oil/water to mix is it ? is the car using coolant ?

[AndersDK]

I wouldnt have thought the vent holes would let in water, if water could get into the oil through there then i would imagine you would get fluid coming out ?
What about the oil cooler ? its not allowing the oil/water to mix is it ? is the car using coolant ?

Agree -

Check the coolant for ATF contamination.
It might not be a wading problem at all even first off.

There is a (small) vent on top of the box somewhere which protrudes the box. The vent should have a small cap.
This is only there to cater for normal temperature related fluid volume changes.
Only if the engine bay has been truly flooded you will get water in here - in small amounts.
It is very easy to modify this for wading/fording : simply clamp a length of tube over the vent and lead the tube to a hole in the air filter box.
Same approach with the dipstick/filler hole.

Finally the air filter box intake duct should be modified to sit as high as possible.

Might be a good future investment - on all cars you have - or get.
Extreme rainstorms are to be expected these years ...

[bv2991]

Hi fellas,

thanks for the reply.

I'm really sure it's not water from the coolant. I've changed the ATF about 3000 km ago and there's no water contamination, only normal dark-colour dirty ATF. After heavy-storm driving, the ATF turned cloudy....and that was the first time this year I've driven it through noticeably deep standing water (okay...3-5 cm).

The vent tube is right up on the 'box and given that it's covered and the aperture was only small (1 cm?) it couldn't be the culprit.

But this was like water got scooped in (looking at the ATF)....I'm pretty positive it's the bellhousing vent holes. (Also given that it's location and position is very good to take in water, facing forward like brake cooling ducts).

I'll probably try to patch a duct tape there temporarily and see the result...
In the meantime, I'll have to drain and refill more ATF till it's clear again.

Cheers.

[bv2991]

Hello all,

drained and refilled another 2 litres ATF over 2 days, the colour is much improved. Although the shifting performance was not noticeably affected after the storm-driving, I changed it anyway.

I had a good chance to have a look at a Cit Picasso and a Pug 307 yesterday. Peeked under the bumper and I noticed that there were no vent holes on the AL4 'boxes. Hmm...makes you wonder isn't it?

Now another problem cropped up....should I take a Picasso or a 307?

[AndersDK]

There is no way that the ATF can be contaminated through the vent holes.
As Wheeler already pointed out, if that was the case, you would as well lose ATF out from the same place.
And thats not going to happen.

Unless a major gearbox fault has occurred.

[bv2991]

Honestly, I'm at a lost myself.

But, just to check the position of the breather tube, refer below:




It's way up on the gearbox and I'd say well protected from road splash. Now I'm really frowning whenever it's raining heavily......