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Omega Help Area => Omega General Help => Topic started by: rds on 08 November 2019, 01:25:54

Title: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: rds on 08 November 2019, 01:25:54
Hello all

I know this has been asked before but i want to ask it my way!!....and hopefully get views from those who have actually done the full flush with transmission cleaning fluid rather  than just theorising, please.

Popped down to local auto trans garage to get a quote today. After 75k I think the car deserves the job anyway.

The garage would prefer just to drop the sumps and re-fill the amount of trans fluid they drained from there, but as we know that will leave a lot of the old fluid in the torque converter and cooler. I don't really want to do this several times just to get the old stuff out.

They also repeat what i see a lot of people saying on the web regarding full flushes which is that the trans cleaner fluid which they pump through is quite aggressive and will loosen muck/material shed from the bands and cause slipping or blockages when the new fluid goes in.

However, I cannot see what the point of a part-change is.

Also, if you were to just drop the sumps, fill back up and do the same a few more times, I cannot see how will that differ from flushing out the whole lot but without using the transmission cleaner. fluid

So, in relation to this 2.2 with 75k om the clock, all gentle usage with no towing/racing, always in neutral (ie not in-gear against the brake) at standstill, what is the general feeling about the full flush with trans cleaner as opposed to a mere full (or as near as can be done) change of fluid?

Thanks in advance

RDS



Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Kevin Wood on 08 November 2019, 04:44:25
It's worth dropping the sumps anyway so you can clean out the sumps and remove any swarf from the magnet in the sump, and also replace or clean out (with paraffin) the filter.

I'd say at 75k you shouldn't worry about any debris getting flushed out. In any case, that's what the filter's there to catch. Such stories are @rse covering by garages on the whole, IMHO. That said, I'd only flush with clean ATF, not any other agent.

We've always recommended just dropping the sumps and then refilling and checking the level with engine running after a short drive. Yes, there's a litre or two of fluid you can't get to but as long as you haven't left it until it's minging that doesn't really matter.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Diamond Black Geezer on 08 November 2019, 08:49:42
I'd second that. The 'box is a 'sealed for life' unit, and only recommends fluid change if a certain number of miles is exceeded in the first year or whatever of driving. That was a looong time ago now! So of course a full fluid change would be the ideal, however at 75k yours is the condition of gearbox many on here would love to get their hands on!

My car's done 209k now, and didn't get it's (partial) fluid change until about 190k, car ran a touch better but wasn't 'bad' even before the change.

Changing the oil at 75k is preventative maintenance, be it full or 'partial'.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Andy B on 08 November 2019, 17:59:11
Does selecting neutral instead of leaving drive actually gain anything? I always leave an auto in Drive and had no problems in any car.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Doctor Gollum on 08 November 2019, 18:01:01
Presumably it reduces strain on the brake band surfaces  :-\
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Kevin Wood on 08 November 2019, 18:27:58
Presumably it reduces strain on the brake band surfaces  :-\

All the friction surfaces are fully engaged / disengaged except when changing, so it just means the torque converter isn't heating up the fluid as much (and saves a little fuel).
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Andy B on 08 November 2019, 19:03:39
Presumably it reduces strain on the brake band surfaces  :-\

All the friction surfaces are fully engaged / disengaged except when changing, so it just means the torque converter isn't heating up the fluid as much (and saves a little fuel).

I'll get 'HOLD'  deleted from my Merc then  ::)
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Doctor Gollum on 08 November 2019, 19:04:33
That presumably works via the ABS, not the GB ;)

Also, you'll probably find that it unholds after about 30 seconds. If you're stopped longer the parking brake and neutral being more appropriate...
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Diamond Black Geezer on 08 November 2019, 19:04:59
Ive often wondered this, it 'feels' like you're wearing out something by having your foot on brake, in D, feels 'bad practice', but good to know.  :y
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: biggriffin on 08 November 2019, 19:05:12
Abridged version.
 Go to BnQ buy fence sprayer.
 Buy some shower gel, chose some clothes you want to throw away.
 Get 9L of Dex3.
 Axle standsx4
Trolley jack,
Various hand tools.
 Old piece of carpet.
Empty 10L drum cut in half Top to bottom
Milk crate.

Jack car up, place axle stands, put carpet under car, putmilk crate under,put drum on milk crate, undo level plug, small amount oilcomes out the nto drum, undo front sump,  whoosh, ,oil in drum and over you, repeat for rear sump,,  then remove filter, clean in parrafin, sumps too, undo cooler pipes, blow thro, reconnect,,  clean and dry parts, smear sumps with goo of choice, refit filter n sumps... Fill spraery with 6-7L oil, put hose into filler hole pump away till it dribbles out, fit level plug,,,, start car,, cycle gears, remove level plug fill again untill drips out.  When you finish, you will see the reason for shower gel and throw away clothes,,, It's easier if you have access to a pit or ramp.

Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Andy B on 08 November 2019, 19:06:03
That presumably works via the ABS, not the GB ;)

It does.....  but leaves the car in gear  ;)
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Andy B on 08 November 2019, 19:09:11
.....
Also, you'll probably find that it unholds after about 30 seconds. If you're stopped longer the parking brake and neutral being more appropriate...

I'll try it but don't think it does. I know it selects Park if you open the driver's door while being held.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Doctor Gollum on 08 November 2019, 19:18:58
Ostensibly there to stop roll back as you engage gear and pull away :y

Applying Park when the door is opened makes sense as it will stop the car driving off or worse ;)
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Andy B on 08 November 2019, 19:27:44
Ostensibly there to stop roll back as you engage gear and pull away :y

.....

That what your left foot is for  ;)
The R Class had hill start assist to do that but it only held the brakes on for 'a short time  :)
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Andy B on 08 November 2019, 19:29:12
....
 

Applying Park when the door is opened makes sense as it will stop the car driving off or worse ;)

But .... you can engage Drive with the door opened
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Doctor Gollum on 08 November 2019, 19:32:35
....
 

Applying Park when the door is opened makes sense as it will stop the car driving off or worse ;)

But .... you can engage Drive with the door opened
Not sure if that's a German thing or an Alabama one :D
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: robson on 09 November 2019, 09:32:27
biggriffins write up is very comprehensive but I would not be very happy working  under a car on 4 axle stands.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Nick W on 09 November 2019, 10:25:21
biggriffins write up is very comprehensive but I would not be very happy working  under a car on 4 axle stands.


why not? ???
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Doctor Gollum on 09 November 2019, 10:52:06
The important bit is that you're working on solid, level ground.

Working on a tarmac drive with a slight slope is probably less than ideal, so I tend to have one end/side on ramps. Tother end can then be safely lifted as high as you need it  :y
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: robson on 09 November 2019, 15:38:42
Yes Doc you have explained exactly what was on my mind quite recently a young man in this area   was killed when the support for the car moved and he was trapped underneath.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: BazaJT on 10 November 2019, 19:19:31
I know it's a lot more of a faff about but I'd go for partial changes[500 to 1000mls between changes] over a "one hit" full flush through.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: rds on 17 November 2019, 21:38:33
Hello All

I'd just like to thank everyone for their input and apologise for my silence: a computer "upgrade" has kept me offline for ages!!

Anyway, the items about a level drive are very pertinent as mine is not and I had toyed with using the slope to my advantage. However we also know of a person killed by improper jacking/securing procedures and I have therefore been prevaricating.

I am going for a full flush with trans fluid, not the cleaner, hopefully this week. I will report back....good or bad!!

Cheers

RDS
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: Nick W on 19 November 2019, 12:18:53
I know it's a lot more of a faff about but I'd go for partial changes[500 to 1000mls between changes] over a "one hit" full flush through.


you could tap into the trans cooler hoses and use one bucket full of fresh ATF and another for the old. Once you get clean new fluid in the old bucket, reconnect the hoses and call it done.


This doesn't check the level though, so you'll still have to do that. Nor does it clean the filter if that's a concern.
Title: Re: Auto trans fluid full change with or without full flush with trans cleaner?
Post by: rds on 21 November 2019, 12:57:15
Yes, i am going to change the filter and gaskets AND fit two drain-able sumps.

RDS