Trans filter change
Thread Starter
Junior Member
Joined: Mar 2022
Posts: 47
Likes: 10
From: Florida
2013 C63
Trans filter change
Good afternoon
I have a question out of curiosity. I just performed the simple trans filter swap on my 2013 C63. All went well as far as I can tell. But the process isn't 100% clear. When the drain plug is first removed, you get x amount of fluid to drain out, popping the overflow plug, the rest comes out. No problem. But to refill, you add 3 liters or so, warm trans, add another liter or two, let drain and replace drain plug. So the question, how is this considered full when the initial removal of the drain plug lets out about 1/2 liter? Just want to be sure it's topped off correctly.
Thanks!
I have a question out of curiosity. I just performed the simple trans filter swap on my 2013 C63. All went well as far as I can tell. But the process isn't 100% clear. When the drain plug is first removed, you get x amount of fluid to drain out, popping the overflow plug, the rest comes out. No problem. But to refill, you add 3 liters or so, warm trans, add another liter or two, let drain and replace drain plug. So the question, how is this considered full when the initial removal of the drain plug lets out about 1/2 liter? Just want to be sure it's topped off correctly.
Thanks!
Thread Starter
Junior Member
Joined: Mar 2022
Posts: 47
Likes: 10
From: Florida
2013 C63
True, not an issue there. The question is why does fluid come out when draining prior to popping the overflow plug. But when adding fluid back in, you let the excess fluid drain to the level of the overflow plug. The short answer is, it's just how it's done. But if this is the proper way to fill, then in theory you could remove the drain plug, let the 1/2 liter or so out, replace the drain plug, and the level would be correct. Seems like you'd be short. Anyway, not a big deal, just a question.
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2010 C63 AMG
It's because when it's running some of the fluid is in the pump when it's not running the pump is empty. If you started your drain process while it's running nine or very little would come out
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Joined: Feb 2010
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2014 C63
At one point the dealer "overfilled my trans fluid". I was tearing down the highway in the Florida heat then all the sudden I see a TON of white smoke coming out the rear of the car. Freaked me out at first, but no check engine lights and the car was running fine. I took it in, and they said MB had released a bulletin since to add less fluid. The pressure had built up too high and it blew the trans seal and vented the excess fluid. It hit the exhaust pipes and boom... Steam
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From: Texas
10 C six trizzle
At one point the dealer "overfilled my trans fluid". I was tearing down the highway in the Florida heat then all the sudden I see a TON of white smoke coming out the rear of the car. Freaked me out at first, but no check engine lights and the car was running fine. I took it in, and they said MB had released a bulletin since to add less fluid. The pressure had built up too high and it blew the trans seal and vented the excess fluid. It hit the exhaust pipes and boom... Steam
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Joined: Sep 2009
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From: Houston, TX
2014 E63 AMGs, 2015 F-150 Lariat, 2010 Porsche C4S
Good afternoon
I have a question out of curiosity. I just performed the simple trans filter swap on my 2013 C63. All went well as far as I can tell. But the process isn't 100% clear. When the drain plug is first removed, you get x amount of fluid to drain out, popping the overflow plug, the rest comes out. No problem. But to refill, you add 3 liters or so, warm trans, add another liter or two, let drain and replace drain plug. So the question, how is this considered full when the initial removal of the drain plug lets out about 1/2 liter? Just want to be sure it's topped off correctly.
Thanks!
I have a question out of curiosity. I just performed the simple trans filter swap on my 2013 C63. All went well as far as I can tell. But the process isn't 100% clear. When the drain plug is first removed, you get x amount of fluid to drain out, popping the overflow plug, the rest comes out. No problem. But to refill, you add 3 liters or so, warm trans, add another liter or two, let drain and replace drain plug. So the question, how is this considered full when the initial removal of the drain plug lets out about 1/2 liter? Just want to be sure it's topped off correctly.
Thanks!
Note, the attached is appropriate for a 2010, not sure what version of the trans is, but the procedure is pretty much the same. I can provide you with appropriate docs if you post your VIN.
Regards,
Joe
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Joined: Apr 2013
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From: Culver City, CA
F10 M5 Comp, 2012 Ford Raptor
At one point the dealer "overfilled my trans fluid". I was tearing down the highway in the Florida heat then all the sudden I see a TON of white smoke coming out the rear of the car. Freaked me out at first, but no check engine lights and the car was running fine. I took it in, and they said MB had released a bulletin since to add less fluid. The pressure had built up too high and it blew the trans seal and vented the excess fluid. It hit the exhaust pipes and boom... Steam
Senior Member
Joined: Jan 2018
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From: Whitehouse Station, NJ
2012 C63 P31 Sedan
Out of curiosity, does anyone know why the level is set as a specific temperature? Is there a thermostatic valve that sends fluid through the cooling loop, or is it always being actively pumped?
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2013 c63 AMG P30 Coupe
Oil takes up more volume as the temperature rises. You need it at the right temperature in order to fill the proper amount of oil when using the overflow drain. If you fill it cold you will end up overfilling; and if you fill it when too hot, it will be underfilled.
Thread Starter
Junior Member
Joined: Mar 2022
Posts: 47
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From: Florida
2013 C63
I landed on the logic that when cold, the fluid settled back to the pan, hence the extra fluid. When warm, and running, the fluid is circulating through other parts of the loop therefore allowing the fluid to be considered topped off once it stops draining from the plug. I’m sure someone knows the actual answer.
Thread Starter
Junior Member
Joined: Mar 2022
Posts: 47
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From: Florida
2013 C63
Yes, drained with engine off. Refilled with engine running, as directed. Once up to temp, add an additional liter or so. Pull fill tube, let fluid drain and cap.
Senior Member
Joined: Jan 2018
Posts: 415
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From: Whitehouse Station, NJ
2012 C63 P31 Sedan
From everything I've looked at regarding oil, it has a very low thermal expansion rate. Something below 0.1% per degree C, so the expansion thing really seems like splitting hairs, unless I'm missing something. However, anytime there's a thermostat involved, you always want to reach a temperature that would open the thermostat to ensure everything is filled properly (like with coolant for example).
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Joined: Dec 2005
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From: NJ
2009 SL63 AMG
Drain cold, fill cold...then start the engine and begin the level-setting procedure.
It's a bit of an oddball filling procedure, frankly. First time I serviced a 722.9, I used a 3L capacity pump and it was a PITA, especially with the larger Weistec pan.
There's a 6L capacity transmission fill pump out there that will make the job a lot easier.
Last edited by HLG600; Apr 9, 2022 at 08:58 AM.
Thread Starter
Junior Member
Joined: Mar 2022
Posts: 47
Likes: 10
From: Florida
2013 C63
I hope not for the initial fill.
Drain cold, fill cold...then start the engine and begin the level-setting procedure.
It's a bit of an oddball filling procedure, frankly. First time I serviced a 722.9, I used a 3L capacity pump and it was a PITA, especially with the larger Weistec pan.
There's a 6L capacity transmission fill pump out there that will make the job a lot easier.
Drain cold, fill cold...then start the engine and begin the level-setting procedure.
It's a bit of an oddball filling procedure, frankly. First time I serviced a 722.9, I used a 3L capacity pump and it was a PITA, especially with the larger Weistec pan.
There's a 6L capacity transmission fill pump out there that will make the job a lot easier.
Member
Joined: Apr 2021
Posts: 147
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2013 c63 AMG P30 Coupe
I think you have to start to fill before turning on the engine because otherwise the transmission oil pump will be running dry, since it turns on when you start the car. The pump probably uses the oil to cool itself and could be damaged if run for long without oil. Then you need to start the car because the oil level is set based on how much oil is remaining in the pan after oil gets circulated through the pump, transmission, etc.
Thread Starter
Junior Member
Joined: Mar 2022
Posts: 47
Likes: 10
From: Florida
2013 C63
I think you have to start to fill before turning on the engine because otherwise the transmission oil pump will be running dry, since it turns on when you start the car. The pump probably uses the oil to cool itself and could be damaged if run for long without oil. Then you need to start the car because the oil level is set based on how much oil is remaining in the pan after oil gets circulated through the pump, transmission, etc.
