DCT replace fluid and filter question
Thread Starter
Pro
Joined: Oct 2019
Posts: 748
Likes: 661
From: San Jose CA
DCT replace fluid and filter question
I know this topic has been beaten like a horse that's been dead for 6 years but....
I have watched YouTube vids of guys showing how and where the plugs are for changing the DCT fluid. All good. I've also seen the vids showing just replacing the filter. That it is just the filter replacement with minimum fluid loss.
And I usually watch the Rick Conti Tech Tuesday Vids to get direct advice from his Service Tech, Chuck. Well on this one dropped this week. He explains that some guys ask about the fluid 'flush' during a filter only replacement. He says it isn't a flush out and replacement of fluid but a running of the fluid through the filter prior to filter replacement.
at 02:17 of the vid (I'm not concerned about the rest of his comments about the 'extra DCT fluid asked for for other circumstances.
My question...A DYI filter & or full fluid replacement process does not do this procedure. So is it worth taking the chance of not doing it? Or just suck it up and pay GM for the service?
Let the flood gates open!
I have watched YouTube vids of guys showing how and where the plugs are for changing the DCT fluid. All good. I've also seen the vids showing just replacing the filter. That it is just the filter replacement with minimum fluid loss.
And I usually watch the Rick Conti Tech Tuesday Vids to get direct advice from his Service Tech, Chuck. Well on this one dropped this week. He explains that some guys ask about the fluid 'flush' during a filter only replacement. He says it isn't a flush out and replacement of fluid but a running of the fluid through the filter prior to filter replacement.
My question...A DYI filter & or full fluid replacement process does not do this procedure. So is it worth taking the chance of not doing it? Or just suck it up and pay GM for the service?
Let the flood gates open!
Melting Slicks
Joined: Nov 2017
Posts: 3,136
Likes: 672
i know I think I understand then somebody asks a question and the answer is changed here's one one: of those procedures is free but it has to be done in 2 years but GM says the fluid doesn't have to be changed for 3 years. How wrong is that statement or is it that the first oil change is free within the first 2 years along with tire rotation and a fluid check
CF Community Team
Joined: Nov 2005
Posts: 5,262
Likes: 2,897
From: Charlotte N.C.
Depends on the year for what you get free and the time period for the free services. None of that effects the required maintenance and when it’s due either by time or mileage.
For the required maintenance read your manual or the letter everyone has been sent.
For the required maintenance read your manual or the letter everyone has been sent.
i know I think I understand then somebody asks a question and the answer is changed here's one one: of those procedures is free but it has to be done in 2 years but GM says the fluid doesn't have to be changed for 3 years. How wrong is that statement or is it that the first oil change is free within the first 2 years along with tire rotation and a fluid check
Instructor
Joined: Nov 2014
Posts: 203
Likes: 88
From: South Hadley/Boca Raton MA/FL
I'm not sure GM could make this any more complicated if they tried. True story...this just happened to me Monday. I stopped in to our Club sponsor last week and asked for an estimate for the tranny fluid replacement + the additional 2 qts. for the track fill as my '22 has been in service for 34 months.. After them having to do some research I was quoted $745 for 13 qts. and 1.3 hours labor ($180/hr) after our Club discount the next day. OK fast forward to Monday.
I drop off at 8:30AM, around 3:00 I call to check status. I'm told there was a small wrinkle, even though the order explicitly stated the 3 yr fluid replacement, somehow the tech managed to do the tranny flush and filter replacement instead. Fortunately my service advisor caught it and they had to send it back in for the fluid replacement. So I'm all set now, but the filter was replaced at 7500, then again at 22,500 and now a 3rd time at 26,600. Granted they are not a huge dealer, but even they don't understand the maintenance schedule. You really need to be proactive with these cars.
Merry Christmas!
Steve
I drop off at 8:30AM, around 3:00 I call to check status. I'm told there was a small wrinkle, even though the order explicitly stated the 3 yr fluid replacement, somehow the tech managed to do the tranny flush and filter replacement instead. Fortunately my service advisor caught it and they had to send it back in for the fluid replacement. So I'm all set now, but the filter was replaced at 7500, then again at 22,500 and now a 3rd time at 26,600. Granted they are not a huge dealer, but even they don't understand the maintenance schedule. You really need to be proactive with these cars.
Merry Christmas!
Steve
Race Director
Joined: Sep 2016
Posts: 13,180
Likes: 10,528
i know I think I understand then somebody asks a question and the answer is changed here's one one: of those procedures is free but it has to be done in 2 years but GM says the fluid doesn't have to be changed for 3 years. How wrong is that statement or is it that the first oil change is free within the first 2 years along with tire rotation and a fluid check
Race Director
Joined: Sep 2016
Posts: 13,180
Likes: 10,528
I'm not sure GM could make this any more complicated if they tried. True story...this just happened to me Monday. I stopped in to our Club sponsor last week and asked for an estimate for the tranny fluid replacement + the additional 2 qts. for the track fill as my '22 has been in service for 34 months.. After them having to do some research I was quoted $745 for 13 qts. and 1.3 hours labor ($180/hr) after our Club discount the next day. OK fast forward to Monday.
I drop off at 8:30AM, around 3:00 I call to check status. I'm told there was a small wrinkle, even though the order explicitly stated the 3 yr fluid replacement, somehow the tech managed to do the tranny flush and filter replacement instead. Fortunately my service advisor caught it and they had to send it back in for the fluid replacement. So I'm all set now, but the filter was replaced at 7500, then again at 22,500 and now a 3rd time at 26,600. Granted they are not a huge dealer, but even they don't understand the maintenance schedule. You really need to be proactive with these cars.
Merry Christmas!
Steve
I drop off at 8:30AM, around 3:00 I call to check status. I'm told there was a small wrinkle, even though the order explicitly stated the 3 yr fluid replacement, somehow the tech managed to do the tranny flush and filter replacement instead. Fortunately my service advisor caught it and they had to send it back in for the fluid replacement. So I'm all set now, but the filter was replaced at 7500, then again at 22,500 and now a 3rd time at 26,600. Granted they are not a huge dealer, but even they don't understand the maintenance schedule. You really need to be proactive with these cars.
Merry Christmas!
Steve
I don't think your case has anything to do with GM not being clear. It's just a tech who didn't bother the read the service order.
Pro
Joined: Oct 2016
Posts: 709
Likes: 515
From: SoCal
Hydraulic System Flush (HSF) can be done via DIY:
https://www.corvetteforum.com/forums...d-gm-gds2.html
For '23 and later C8s:
https://www.corvetteforum.com/forums...scan-tool.html
Or "just drive" it per these GM engineers:
https://www.corvetteforum.com/forums...d-gm-gds2.html
For '23 and later C8s:
https://www.corvetteforum.com/forums...scan-tool.html
Or "just drive" it per these GM engineers:
Last edited by kromdom; Dec 12, 2024 at 02:21 PM.
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Race Director
Joined: Sep 2016
Posts: 13,180
Likes: 10,528
I know this topic has been beaten like a horse that's been dead for 6 years but....
I have watched YouTube vids of guys showing how and where the plugs are for changing the DCT fluid. All good. I've also seen the vids showing just replacing the filter. That it is just the filter replacement with minimum fluid loss.
And I usually watch the Rick Conti Tech Tuesday Vids to get direct advice from his Service Tech, Chuck. Well on this one dropped this week. He explains that some guys ask about the fluid 'flush' during a filter only replacement. He says it isn't a flush out and replacement of fluid but a running of the fluid through the filter prior to filter replacement.
CORVETTE CONFUSION C8 DCT TRANSMISSION SERVICING at 02:17 of the vid (I'm not concerned about the rest of his comments about the 'extra DCT fluid asked for for other circumstances.
My question...A DYI filter & or full fluid replacement process does not do this procedure. So is it worth taking the chance of not doing it? Or just suck it up and pay GM for the service?
Let the flood gates open!
I have watched YouTube vids of guys showing how and where the plugs are for changing the DCT fluid. All good. I've also seen the vids showing just replacing the filter. That it is just the filter replacement with minimum fluid loss.
And I usually watch the Rick Conti Tech Tuesday Vids to get direct advice from his Service Tech, Chuck. Well on this one dropped this week. He explains that some guys ask about the fluid 'flush' during a filter only replacement. He says it isn't a flush out and replacement of fluid but a running of the fluid through the filter prior to filter replacement.
CORVETTE CONFUSION C8 DCT TRANSMISSION SERVICING at 02:17 of the vid (I'm not concerned about the rest of his comments about the 'extra DCT fluid asked for for other circumstances.
My question...A DYI filter & or full fluid replacement process does not do this procedure. So is it worth taking the chance of not doing it? Or just suck it up and pay GM for the service?
Let the flood gates open!
The service manual lists the hydraulic system flush as step 1 of the DCT filter change procedure. Every time, not just the first time.
OTOH, during a recorded video session at the Bash last April, Tadge and Josh Holder said for do it yourselfers the flush procedure isn't really necessary. They said it's an extra step they have the dealers do because they can. Hmmm.
Not sure I really see GM requiring dealers to do something that has no real value. And there's nothing in writing to fall back on if you don't have that procedure done and have a DCT failure. Show the video to GM and they'll just show you the service manual procedure. Is that a serious risk? Probably not, but...
One more wrinkle: What year is your C8? 2023 and newer have the software to run the flush built into the car, and there are aftermarket scan tools than can execute it. Pre 2023 cars need the GM scan tool.
You pays your money and takes your chances. The choice is up to you.
Safety Car
Joined: Sep 2000
Posts: 3,604
Likes: 396
From: Austin, TX
Hydraulic System Flush (HSF) can be done via DIY:
https://www.corvetteforum.com/forums...d-gm-gds2.html
For '23 and later C8s:
https://www.corvetteforum.com/forums...scan-tool.html
Or "just drive" it per these GM engineers:
https://youtu.be/J_2P4oVQRrM?si=atn6_SJX-WRpreG-
https://www.corvetteforum.com/forums...d-gm-gds2.html
For '23 and later C8s:
https://www.corvetteforum.com/forums...scan-tool.html
Or "just drive" it per these GM engineers:
https://youtu.be/J_2P4oVQRrM?si=atn6_SJX-WRpreG-
Racer
Joined: Aug 2020
Posts: 412
Likes: 219
From: San Diego, CA
Oops!
Looks like the Foxwell will run the “flush” as well!
https://youtu.be/jqyUOgG1UVY?si=WdXGIjR13cRj7yWN
https://youtu.be/jqyUOgG1UVY?si=WdXGIjR13cRj7yWN
Safety Car
Joined: Sep 2000
Posts: 3,604
Likes: 396
From: Austin, TX
Race Director
Joined: Feb 2011
Posts: 14,741
Likes: 5,605
From: AZ
First, there's no requirement or recommendation to do the flush during a fluid replacement. ONLY during the filter change.
The service manual lists the hydraulic system flush as step 1 of the DCT filter change procedure. Every time, not just the first time.
OTOH, during a recorded video session at the Bash last April, Tadge and Josh Holder said for do it yourselfers the flush procedure isn't really necessary. They said it's an extra step they have the dealers do because they can. Hmmm.
Not sure I really see GM requiring dealers to do something that has no real value. And there's nothing in writing to fall back on if you don't have that procedure done and have a DCT failure. Show the video to GM and they'll just show you the service manual procedure. Is that a serious risk? Probably not, but...
One more wrinkle: What year is your C8? 2023 and newer have the software to run the flush built into the car, and there are aftermarket scan tools than can execute it. Pre 2023 cars need the GM scan tool.
You pays your money and takes your chances. The choice is up to you.
The service manual lists the hydraulic system flush as step 1 of the DCT filter change procedure. Every time, not just the first time.
OTOH, during a recorded video session at the Bash last April, Tadge and Josh Holder said for do it yourselfers the flush procedure isn't really necessary. They said it's an extra step they have the dealers do because they can. Hmmm.
Not sure I really see GM requiring dealers to do something that has no real value. And there's nothing in writing to fall back on if you don't have that procedure done and have a DCT failure. Show the video to GM and they'll just show you the service manual procedure. Is that a serious risk? Probably not, but...
One more wrinkle: What year is your C8? 2023 and newer have the software to run the flush built into the car, and there are aftermarket scan tools than can execute it. Pre 2023 cars need the GM scan tool.
You pays your money and takes your chances. The choice is up to you.
Race Director
Joined: Aug 2016
Posts: 12,844
Likes: 10,254
From: Garden Valley CA
I have never heard of this before and no one on the Forum has posted how the cars '23 and newer run the Hydraulic system flush (no fluid involved. I understand at the Bash Sr. Engineers said the car does the "flush" during normal driving. Please provide more info on how to get the '23 and newer cars to run the HSF.
Race Director
Joined: Feb 2011
Posts: 14,741
Likes: 5,605
From: AZ
I know there are scan tools that will do this but Red Mist said the '23 and newer had the software built into them to be able to do the HSF. Buying an aftermarket tool to do it is not "built into" the car. That is why I asked the question.
Last edited by AzDave47; Dec 13, 2024 at 11:50 PM.
Race Director
Joined: Aug 2016
Posts: 12,844
Likes: 10,254
From: Garden Valley CA
The firmware to perform the HSF is built into the C8 DCT modules on 2023 and newer cars. The earlier cars need to have the algorithm temporarily loaded and executed. My understanding is the aftermarket tools don't have the ability temporarily write and execute the algorithm on the earlier cars.
Racer
Joined: Apr 2024
Posts: 353
Likes: 180
From: Michigan
Even the dealerships HAVE TO USE a tool plugged into the vehicle to execute the commands, 2020-2022 and 2023+ models.
Melting Slicks
Joined: Nov 2017
Posts: 3,136
Likes: 672
mrclean1 Look around and read my MUST READ post and I fully support you in dealing with a dealership that doesn't know what they are doing at least you got something done. In a small town if you need a dealership you're almost stuck
Some dealer sell them and that's IT.
Some dealer sell them and that's IT.