Great news !!! What did you heat up the DCT fluid temp to before running the Flush procedure? I believe someone said the tools states to raise the temp to 160 F. Did you take it up to 160 degrees F ?

 

Waiting to hear if someone has a successful outcome with a 2022. Fingers crossed...

 

Looking forward to making use of this Foxwell NT710 unit... Quick question: Does a Foxwell NT710 perform both a hydraulic system flush AND the required leak test?

 

Nope, just tried to do the leak test an it didn't work. I got the "Request rejected by the control module - Request out of range"

In my case, In 2023 I did a DIY 3yr. DCT fluid drain/refill, dropped the pan & replaced the internal filter and canaster filter. I took my car to the dealer to do the flush procedure before swapping the canaster filter. But now I’m wondering if we should be stressing over the flush procedure related to normal maintenance.

I’m a believer in following the service manual instructions but based on this video, I think we can all relax some.

Interesting video

(jump to 1:08). I believe @Andybump actually submitted the question to Corvette today podcast #215. The engineer did say the routine runs during normal driving anyway....

 

He said "a" routine runs during normal highway driving. He did not say it was the Hydraulic System Flush procedure. And, I do not believe it can be the same. As has been discussed at length, the earlier models do not have the software built in to the module so support the HSF. Later models do. Its been cited as the reason most aftermarket tools can't run the HSF on earlier models - though now some can, apparently. So, if the so called highway routine is the same as the HSF, then it would mean it is not running on earlier models. On the other hand, if the highway routine is a different routine, then maybe it runs on all cars. I think the latter is the case. The are different.

In any case, Josh did say if DIYing, then you do not need to run the HSF. Perhaps a nitpick, but he never specifically addressed its affect on the warranty. And he gave very little detail on exactly what it does.

 

Just checking once again to see if anyone has used the Foxwell NT710 and successfully done both the hydraulic system flush AND the required leak test on an 2020, 2021 or 2022 C8 ?

As I looked at the Amazon listing for the tool this afternoon, I see they have a $60 coupon at the moment...... I'm still holding out until I know that it will perform both the HSF and leak test for my 2020...... ANYONE ????

Obviously, GM sees some value in doing the HSF and leak test, although their senior Engineering Mgmt says it's not necessary for DIY'ers..... BUT if I can buy a tool that WILL work for less than $300 it's worth it to me ....

thanks !

 

Any reason you're not willing to purchase and return if it doesn't work? I did, to see if it worked for me (and it didn't) on my 2021. I've seen only one person state it works, but nothing else.

 

^^^ Yes, I can certainly do that and have made plenty of returns to Amazon over the years. It would just be nice to know if others have used it successfully and could post about their experience.

Part of the issue is that I won't need to perform a HSF and leak test until late August or early fall when I'm at 22,500 miles. There is a time limit for returns to Amazon. If I was certain that this tool would work for my 2020 then I would buy it now to get the $60 coupon..... but if it's still a coin toss, then I guess I will wait until I need to actually use the tool and buy it then....... and return it if it won't do the task.

 

Thank you for posting the video and glad to see someone is using some common sense. Makes perfect sense, it is doing the exact same thing when you are driving it.

 

I agree that fine filtering happens all the time when we are driving - all fluid that goes through the lines, valves, and actuators goes through both the the internal coarse filter and the external canister "fine" filter - but it would appear that the Hydraulic System Flush does a bit more than just pump fluid through the fine filter.

The Hydraulic System Flush is procedure that was added to the Service Manual procedures sometime after the 2020 model year was introduced. It appeared in service bulletins as a procedure that attempted to remedy certain transmission related problems indicate by certain diagnostic trouble codes (DTCs). It was added to the manual as a service procedure, and it was also added as step 1 to the procedure for changing the DTC external canister filter - in addition to being called for in various diagnostic and repair procedures. In a 2021 Service Manual, dated 2023, it is described this way: " This test executes a procedure in the TCM software to actuate the solenoids in a specific manner to flush debris from the system." My sense tell me that something described like that, and called for by multiple service procedures, must not be doing the same thing as simply driving down the highway.

While Josh did say (in that 2024 Bash response) the Hydraulic System Flush procedure "forces transmission fluid through the fine filter", he did not mention that it "executes a procedure in the TCM software to actuate the solenoids in a specific manner to flush debris from the system", although that description appears in the service procedures. And he did not say the HSF executes while driving down the highway. What he said was "when you’re driving steady state like say down the highway, we run a routine in the transmission that will force more of that fluid through the fine filter. " He did not say that the "routine" is the same as the Hydraulic System Flush procedure. He did say that if you are DIYing the DCT filter change, you don't have to run the Hydraulic System Flush - not disputing that.

Here is Josh's complete response during the 2024 Bash:
""The hydraulic system flush does kind’a the way its described. It forces transmission fluid through the fine filter that you replace. So, at a dealership they can hook up the dealer service tool to the and run a routine that will tell the trans control module to do this fluid filter flush. And because the car is already hoisted on the rack, the technician’s already got the panels off, there’s some other work he’s doing, this kinda happens in parallel in the background. So we’re doing it at a dealer visit because we can. And we can take the last bit whatever contamination might be in the oil and get it into the filter before the technician replaces it. Do it yourselfers have become nervous that hey now I can’t do it myself, I don’t have a service tool, I can’t force this routine. You don’t have to do the routine. Like I said we do it because we can, but the fine filtering routine happens during normal driving anyway. In fact, when you’re driving steady state like say down the highway, we run a routine in the transmission that will force more of that fluid through the fine filter. So normal driving is doing this. If you are a do-it-yourselfer, you don’t want anyone else touching your car, you can change the trans filter without running this routine."

 

Just checking once again on whether or not the Foxwell NT710 and successfully done both the hydraulic system flush AND the required leak test on an 2020, 2021 or 2022 C8 ?

Amazon has a coupon for $60 off that ends April 1......

Has anyone else tried this out in the past few weeks? Unfortunately, some folks say it works, and others say no, it doesn't. Just trying to collect data prior to purchasing.

thanks,
Richard

 

The 'Flush' procedure went well (maybe ??) though it only took 5 minutes rather than the mentioned 10 minutes before being stated as 'process complete' on the screen. The engine reached & was held @ 2000 RPM for the entirety of that procedure. It's hard to confirm what actually went on inside the DCT which is the reason for my concern. Should I trust the NT710?
But when attempting the 'Leak Test' (a mentioned 30 second process) the screen posted a note stating that the car's ECU had rejected the request and the leak test was thus cancelled.
So yes to a hydraulic system fluid flush procedure but no to a leak test when using a Foxwell NT710 on my 2020 Corvette C8 Z51.

 

^^^ Thanks for the follow through reply !!!

Richard

 

Did you have to download software/program to do the flush or was it already pre programed in the Foxwell NT710?

 

After purchase, I charged the NT710 internal battery, set-up it's wi-fi feature to my home's wireless Internet, updated the unit's software to a current version and once all of that was completed.... I plugged it into my Corvette's OBD port and performed the processes request on the scanner unit screen to finally accomplish the 'hydraulic system flush'. No other external program / software was downloaded or used.

 

Thank you

 

Here’s an eMail dialogue w/Foxwell customer service.
I asked:
"Using a Foxwell NT710 scanner - I'm looking to perform a transmission hydraulic system flush procedure on my 2020 Corvette C8 Z51"

Foxwell answers:
"...We have confirmed that the NT710 is compatible with your vehicle and supports the functions you need...."

 

Has anybody asked Foxwell customer service about performing the leakage test on early models?

 

On 2023 and later cars the flush program is coded in the TCM (Transmission Control Module). So the Foxwell doesn't need the software on the device, it just needs to know how to tell the TCM to execute the program.

On 20 - 22 MY cars the flush program is NOT coded in the TCM, and the Foxwell can't perform it.

Mjultiple people have reported the Foxwell failed on early MY cars.

 

@Jacques Albrecht has peported in this thread that the Foxwell NT710 performed the hydraulic system flush on his 2020 C8 however couldn't perform the post filter replacement leak check.