Thread: Transmission drop and drain volume on L322?

It’s hard to predict as the capacity is split between the TC and sump and cooler and pipe work.

About 5 +/- litres is what you get in a drop from a ZF6.

Here’s two ideas;

1. Pump out on the tranny oil cooler line to the radiator exactly (or slightly less) 5 litres. This method is quite quick clean and easy if you have an assistant. Use a graduated container to catch it using a hose extension. Be ready to turn off engine as it pumps fast.

Advantage is you don’t need to remove the sump.

2. When draining the sump catch a litre or two of old fluid. You can run this through some coffee filter paper but at least you have some spare to put back if you need more than 5 litres. Since you are only replacing a % of the total capacity putting a bit back in makes no difference.

In this method you usually remove the sump and replace the gasket, filter and mechatronics seal with associated hardship and swear words. Replace the rubber seals above the mechatronics plate also while you are there.

Originally Posted by PerthDisco

It’s hard to predict as the capacity is split between the TC and sump and cooler and pipe work.

About 5 +/- litres is what you get in a drop from a ZF6.

Here’s two ideas;

1. Pump out on the tranny oil cooler line to the radiator exactly (or slightly less) 5 litres. This method is quite quick clean and easy if you have an assistant. Use a graduated container to catch it using a hose extension. Be ready to turn off engine as it pumps fast.

Advantage is you don’t need to remove the sump.

2. When draining the sump catch a litre or two of old fluid. You can run this through some coffee filter paper but at least you have some spare to put back if you need more than 5 litres. Since you are only replacing a % of the total capacity putting a bit back in makes no difference.

In this method you usually remove the sump and replace the gasket, filter and mechatronics seal with associated hardship and swear words. Replace the rubber seals above the mechatronics plate also while you are there.

Many thanks for info and options.
QUERY??
If I were to keep pumping clean fluid through the tranny cooler line, does that circulate freely through the transmission and the torque convertor?
I have been looking for a way to flush the old fluid from the torque convertor when I do a full service.
Have seen various "pumps" shown in online vids, that LR owners have made to "flush" out the transmission of the oil that remains when you change filter etc.
And I hear terms like "power flush", but imagine that to be a pump that runs in sync with the running vehicle, inserting clean fluid into the trans while collecting old outgoing fluid.

My concern was that manually pumping fluid in through cooler line might work against some valve or seals that might be there to only work when vehicle is running,
OR that the returning fluid from the cooler might be going to the sump on return (so it would just run out if I was pumping it in via the trans return line).

I don't have a flow diagram for the returning fluid, but have usually disconnected the cooler outlet pipe and run the engine briefly to allow it to pump out some of the oil that remains after dropping sump oil. (This is after I have replaced pan and new filter and fresh fluid in sump.)
The fluid that flows out looks to be old fluid (by colour), so I assumed it was coming from torque convertor.
I pump out a litre, then top up sump and pump out another litre. After about 4 litres it does appear to be pumping cleaner fluid.

I have always wondered if i could just hook up my pump, and pump directly through the return line into the transmission and that would simply flush the TC of remaining old fluid??

Originally Posted by vbrab

Many thanks for info and options.
QUERY??
If I were to keep pumping clean fluid through the tranny cooler line, does that circulate freely through the transmission and the torque convertor?
I have been looking for a way to flush the old fluid from the torque convertor when I do a full service.
Have seen various "pumps" shown in online vids, that LR owners have made to "flush" out the transmission of the oil that remains when you change filter etc.
And I hear terms like "power flush", but imagine that to be a pump that runs in sync with the running vehicle, inserting clean fluid into the trans while collecting old outgoing fluid.

My concern was that manually pumping fluid in through cooler line might work against some valve or seals that might be there to only work when vehicle is running,
OR that the returning fluid from the cooler might be going to the sump on return (so it would just run out if I was pumping it in via the trans return line).

I don't have a flow diagram for the returning fluid, but have usually disconnected the cooler outlet pipe and run the engine briefly to allow it to pump out some of the oil that remains after dropping sump oil. (This is after I have replaced pan and new filter and fresh fluid in sump.)
The fluid that flows out looks to be old fluid (by colour), so I assumed it was coming from torque convertor.
I pump out a litre, then top up sump and pump out another litre. After about 4 litres it does appear to be pumping cleaner fluid.

I have always wondered if i could just hook up my pump, and pump directly through the return line into the transmission and that would simply flush the TC of remaining old fluid??

Don’t know for sure.

People do pressure pump an equivalent amount in equal to that pumped out at the radiator cooler. The system won’t draw in fluid while pumping out. I’ve not heard this causing trouble.

The magic flush systems must automate this to some degree.

I’d suggest to use the system to pump out with motor running then add that amount via the filler at the sump if the intent is to introduce new fluid.

At least with the latter you are checking and setting the level right.

Originally Posted by PerthDisco

Don’t know for sure.

People do pressure pump an equivalent amount in equal to that pumped out at the radiator cooler. The system won’t draw in fluid while pumping out. I’ve not heard this causing trouble.

The magic flush systems must automate this to some degree.

I’d suggest to use the system to pump out with motor running then add that amount via the filler at the sump if the intent is to introduce new fluid.

At least with the latter you are checking and setting the level right.

I have tried doing the pump out some through the trans cooler and then top it up again with fresh routine, but problem was that new oil still mixing with old oil, so really uses much oil to get it flushed clean (er).
However, have just asked transmission place for a quote on full service with, filter, mechatronic unit and power flush, so that entire system cleaned. They reckon $1100 (ouch!) and they use 15 litres flushing, so it appears they use a lot of oil washing TC clean as well.
I figure I will get trans cleaned out when I get to the city. as still not happy with the colour despite adding fresh fluid to improve what is in there.
Transmission has had fluid changes every 40k since new, and still it looks dark, so a full flush might be what is needed.
Did a fluid change on a D3 that had done 200k with nil service ever (dealer giving the "sealed for life" routine), and that looked jet black (see pic), at least current fluid colour is just brown.
DSC_3571.jpg

My understanding is the pump in the transmission sucks up the oil from the sump and pumps it through the system including the TC to the oil cooler and then back to the sump.

To minimise mixing of old and new oil I first drain the sump and fill with fresh fluid and then disconnect the in line to the oil cooler and at an extension to catch oil as it is pumped out later. On the oil cooler in side I connect an extension to which I can pump in fresh oil as the dirty oil goes out.

I then start the engine and as fluid comes out the oil cooler line I pump in fresh oil into the oil cooler which then goes back to the sump.

The theory is that as the fresh oil is sucked up in the sump it forces the dirty oil out into your bucket while fresh oil is going back in. The reality works with the fine passages but where there large pools like in the TC there will be some mixing but overall using about 10 litres does a pretty good job of getting fresh oil into the system with the least amount of mixing of old and new oils.

The only other alternatives are a mega flush which will use a lot more oil with only a marginally better job.

You can also just do a basic drain of the sump and refill every second service of the car which also works pretty well.

Garry

Thanks for flow info, I was thinking that if the fluid came through cooler direct from TC, then as long as I could feed new oil back into the sump at same rate as it pumped out then it would be possible to perhaps change out all the dirty fluid.
It does appear to have a pretty good flow rate out of the cooler.
I just didn't want to be somehow depriving system of fluid.
I may attempt it next time with an extra pair of hands.

Originally Posted by 101RRS

My understanding is the pump in the transmission sucks up the oil from the sump and pumps it through the system including the TC to the oil cooler and then back to the sump.

To minimise mixing of old and new oil I first drain the sump and fill with fresh fluid and then disconnect the in line to the oil cooler and at an extension to catch oil as it is pumped out later. On the oil cooler in side I connect an extension to which I can pump in fresh oil as the dirty oil goes out.

I then start the engine and as fluid comes out the oil cooler line I pump in fresh oil into the oil cooler which then goes back to the sump.

The theory is that as the fresh oil is sucked up in the sump it forces the dirty oil out into your bucket while fresh oil is going back in. The reality works with the fine passages but where there large pools like in the TC there will be some mixing but overall using about 10 litres does a pretty good job of getting fresh oil into the system with the least amount of mixing of old and new oils.

The only other alternatives are a mega flush which will use a lot more oil with only a marginally better job.

You can also just do a basic drain of the sump and refill every second service of the car which also works pretty well.

Garry