Mazda 6 - ATF fluid

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Mon 9 Jan 2012 21:37
Mazda 6 - ATF fluid - balleballe

I have an 02 plate mazda 6, with a 4 speed autobox.

I last checked the ATF dipstick approx 4 months ago (used to check every fortnight but it always stayed the same). and the level was around 1cm higher on the dipstick than it is now;

I was curious to see if I had a leak so every day for the last week, before leaving for work - as soon as I've started the engine i've popped the hood and measured the ATF fluid level (parked in the same spot every time) and its always at the exact same place.

So - either I have a very slow leak, or the temperature is to blame for the low reading (as ATF's volume increases with temperature)

Which is it likely to be?

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Wed 18 Jan 2012 22:24
Mazda 6 - ATF fluid - balleballe

Well, its definately a slow 'leak'

The car's only worth around 1.2-1.3k so I don't think theres any use in 'repairing' the problem as it seems an expensive one - and mazda want £60 an hour to diagnose the problem.

Would using something like "wynn's automatic transmission & power steering stop leak" be a wise move?

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Thu 19 Jan 2012 08:04
Mazda 6 - ATF fluid - RT

Automatic gearboxes should have their flud level checked when the transmission is fully warmed up, say 10-20 miles after startup - so I'm not sure you can tell anything by checking cold.

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Thu 19 Jan 2012 21:45
Mazda 6 - ATF fluid - balleballe

The mechanic at mazda told me that as long as the transmission is in park - I can check it 'cold' as long I use the 20 degree markings and not the 60 degree marking. The fact that it has been decreasing using the same check method suggests a leak.

I just realised that the 'sympoms' started around the same time I had a new radiator put in.

Googling reveals that it's common for an ATF leak to manifest after a radiator has been installed due to leaking fluid lines around the transmission fluid cooler (within the radiator) if incorrectly installed

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Thu 19 Jan 2012 22:08
Mazda 6 - ATF fluid - RT

I don't know about Mazda but there have been some autobox failures caused by corrosion in the radiator which allows coolant to get into the ATF.

As you suspect a leak, add an accurate check to the engine coolant level.

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Thu 19 Jan 2012 22:25
Mazda 6 - ATF fluid - balleballe

if coolant was being 'added' to the atf - shouldnt the value rise on the dipstick? Or am I missing something here

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Fri 20 Jan 2012 07:51
Mazda 6 - ATF fluid - RT

The net flow of fluid could be either way - the important thing is that coolant in the ATF will wreck the transmission - whereas ATF in the coolant won't do that much harm.

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Fri 20 Jan 2012 10:37
Mazda 6 - ATF fluid - balleballe

So took it to my trusty local mechanic who fitted the radiator - took off the underside engine cover and had a look around

There's a lean in one of my driveshafts - ATF is leaking from around the seal (looks and smells like ATF)- no other leaks anywhere else

Problem solved - ordering in near side replacement and all is well

One thing I mentioned is that the car revs but does not quite pick up speed like it used to, a massive lack in response compared to what it used to be. Sometimes I have to take my foot off the throttle for it to change gear otherwise it will hold the gear it's in far too long

He mentioned it sounds a little like clutch slippage. I'm hoping that things return to 'normal' after the leak is fixed

When I checked my ATF a few weeks ago it was well below the required amount on the dipstick - around an inch or so below minimum. I just hope it hasnt done any permanent damage

Edited by balleballe on 20/01/2012 at 10:38

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Fri 20 Jan 2012 11:12
Mazda 6 - ATF fluid - RT
One thing I mentioned is that the car revs but does not quite pick up speed like it used to, a massive lack in response compared to what it used to be. Sometimes I have to take my foot off the throttle for it to change gear otherwise it will hold the gear it's in far too long

He mentioned it sounds a little like clutch slippage. I'm hoping that things return to 'normal' after the leak is fixed

For myself, I'd get the ATF changed on a 10 year old car - as it deteriorates it can cause just those problems.

If you've got the owner's manual check what ATF it needs - there are many, Dexron isn't completely universal - otherwise check with Mazda UK or Opie Oil.

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Fri 20 Jan 2012 21:55
Mazda 6 - ATF fluid - balleballe

I changed the ATF at 88k and also just changed it at 100k (500 miles ago) when I noticed the leak - hoping it would solve the problem

Yep - takes mazda's own, mot dextron 3 or 5. specification m-v

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