MM 0 1 7 Brake Fluid Change

[MrFixit]

I noticed that also, I am guessing they are just letting you know that when the fluid level gets low during draining the brake warning light will come on, but that this is expected, and it will go away as soon as brake pressure is applied.

Pay special attention to Posts # 56, 61, 64 in this thread. The warning lights illuminated as expected, but they do NOT go away with the application of brake pressure. In my case, clearing a code solved the problem. In @NorCalPete 's case, he could not find a code, but the lights eventually went away. I don't know if mine would have cleard on it's own eventually, but it does not work as described in the procedure.

 

[gedwin]

I did my MM 7 brake bleeding this past weekend (2019 base). I wanted first and foremost to thank previous posters in this thread! It was so very helpful to know 1) that two rounds of bleeding are required and 2) that error codes may appear afterward that must be cleared. Knowing both of these facts in advance saved me a lot of worry and helped ensure I did the job correctly.

The bleeding was mostly straightforward and conventional; I use the old school method of having a partner (i.e., son) press and release the pedal on command as I operate the bleed stems (10 mm wrench for the front, 11 mm on the rear). I chose to be in the "Ready" mode as my interpretation of "On" from the service manual. The first round of bleeding in this mode went fine until I was almost done with the final wheel, back left. During one of the presses, my son reported that the display screen lit up like a Christmas tree with 8 or so warning about systems failings and also he said that the brake pedal feel changed noticeably for his future presses. (No reason for this to have triggered at that particular point; I had been careful to keep the reservoir topped off, so that wasn't an issue.) Since I had already felt I was done at that final wheel (clear fluid), I had him do one or two more presses for good measure, then considered the first phase done. We turned the power off, waited as instructed, and then did the power off bleeds without event.

When I had everything back together, I powered on and noted all the systems-are-off warnings and dash lights remained activated. Press and hold brake pedal did nothing. I attempted to drive (backing out of the garage), and braking was bizarre: weird pulsing, soft pedal and significant, unusual noises. This is where I was so glad to have read previous posts here, otherwise I would have been panicking that I had ruined my car! But, armed with that foreknowledge, I plugged in my OBDII scanner and read codes P1E52 and P25A2. I cleared these codes, powered down the car, and then powered on again. Everything thankfully appeared normal on the dash, and a test drive verified normal braking.

I'm concluding that some specific event/condition during the system-on phase of bleeding triggered the errors. So, I imagine it is possible to complete the system-on bleeding without triggering the error codes, either through luck or by eventually figuring out exactly what type of brake press motion can trigger the sensor involved. But, in any event, I think this explains why it can be a hit-or-miss experience; I expect some people could bleed successfully without having any trouble at all. I am not sure if my DTC codes (P1E52 and P25A2) are the same/equivalent to what others have had.

 

[gedwin]

Also, I think the time frame for this service is pretty well established earlier in this thread, but for the record: I cleared MM 7 (via the dashboard interface) yesterday after completing the brake fluid change. Today, when I read the car by OBDII (checking battery capacity for kicks), I noticed that Maintenance Item 7 is listed as due in 1094 days. Exactly 3 years from yesterday.

 

[megreyhair]

My fluid was quite clear at the 3 year mark. So I waited another year to do my fluid change and did it yesterdy. I didn't any of the warning lights some of you were having. The posted instruction said the brake pedal will sink when bleeding in the "on" phase. But my wife said she didn't feel the pedal sinking in while it was being bleed. Is that normal ? The pedal did sink during the 'off' phase bleed. I also noticed that the fluid in 2nd reservoir, the one by the passenger side is darker then few fluid. Seems like the fluid in there didn't get change. I might try to bleed it this weekend with the bleed valve under that reservoir.

 

[MrFixit]

The posted instruction said the brake pedal will sink when bleeding in the "on" phase. But my wife said she didn't feel the pedal sinking in while it was being bleed. Is that normal ?

I assume fluid was coming out even though your wife did not perceive the sinking pedal?

If a lot of fluid came out during both of these phases, then I would declare victory.
I see no reason to bleed again from a different spot than what is called for in the procedure assuming fluid was coming out readily.

I utilized a total of 36 ounces of new fluid from start to finish.

 

[megreyhair]

I assume fluid was coming out even though your wife did not perceive the sinking pedal?

If a lot of fluid came out during both of these phases, then I would declare victory.
I see no reason to bleed again from a different spot than what is called for in the procedure assuming fluid was coming out readily.

I utilized a total of 36 ounces of new fluid from start to finish.

Of course fluid was coming out. I would have sounded the alarm if nothing was coming out. I used 3/4 of a 32oz bottle.

 

[geokilla]

Hey guys, my Honda Clarity is due for a brake fluid change. I've had the car for 4 years and almost 60k km in mainly city traffic. How much brake fluid did you guys use? I'm looking to upgrade from the Honda DOT3 fluid. Looking at getting some ATE TYP 200 or Pentosin DOT4. Sounds like 1L is a safe bet given the abnormal brake fluid change instructions as per Honda?

 

[MrFixit]

The manual for the Clarity (and other Honda vehicles) is specific about using Honda brand DOT3 fluid. There is a caveat about using other DOT3 or DOT4 fluids on a temporary basis if the specified fluid is not available...

Is this just sales hype, or is there some validity to this? You can find some discussions about this topic in the Honda forums, and it seems that Honda does have some proprietary corrosion preventative additives in their fluid. Here is a snip from the manual where the fluid is specified:



I used genuine Honda DOT3 fluid for a couple of reasons. First, this comment in the Honda owners manuals. Second, this brake system is substantially more complicated than others, and I felt like there may be more of the old fluid left behind than when a conventional system is flushed. This would result in an unavoidable mixture of the old and new fluid.

You may be fine with another brand of DOT3, or even DOT4, but it is not clear that a different fluid would represent an "upgrade" and it carries some risk.

I used three 12-oz bottles, and felt it was barely enough. It all depends on how much you flush out during the process. After only 3 years, it was not perfectly obvious when the fluid color changed from old to new when bleeding it out, so I may have bled more than necessary. I found it useful to measure the volume of fluid that I bled out each time to avoid running dry and also to make sure I had enough overall.

 

[Frankwell]

The manual for the Clarity (and other Honda vehicles) is specific about using Honda brand DOT3 fluid. There is a caveat about using other DOT3 or DOT4 fluids on a temporary basis if the specified fluid is not available...

Is this just sales hype, or is there some validity to this? You can find some discussions about this topic in the Honda forums, and it seems that Honda does have some proprietary corrosion preventative additives in their fluid. Here is a snip from the manual where the fluid is specified:

View attachment 16375

I used genuine Honda DOT3 fluid for a couple of reasons. First, this comment in the Honda owners manuals. Second, this brake system is substantially more complicated than others, and I felt like there may be more of the old fluid left behind than when a conventional system is flushed. This would result in an unavoidable mixture of the old and new fluid.

You may be fine with another brand of DOT3, or even DOT4, but it is not clear that a different fluid would represent an "upgrade" and it carries some risk.

I used three 12-oz bottles, and felt it was barely enough. It all depends on how much you flush out during the process. After only 3 years, it was not perfectly obvious when the fluid color changed from old to new when bleeding it out, so I may have bled more than necessary. I found it useful to measure the volume of fluid that I bled out each time to avoid running dry and also to make sure I had enough overall.

I think I would go with the OEM brake fluid also. Of course it's typical for manufacturers to recommend using their products, but in this case it specifically states there could be problems using something else, so whatever the cost savings might be using a different brand doesn't seem to be worth the risk.

 

[Roen]

The manual for the Clarity (and other Honda vehicles) is specific about using Honda brand DOT3 fluid. There is a caveat about using other DOT3 or DOT4 fluids on a temporary basis if the specified fluid is not available...

Is this just sales hype, or is there some validity to this? You can find some discussions about this topic in the Honda forums, and it seems that Honda does have some proprietary corrosion preventative additives in their fluid. Here is a snip from the manual where the fluid is specified:

View attachment 16375

I used genuine Honda DOT3 fluid for a couple of reasons. First, this comment in the Honda owners manuals. Second, this brake system is substantially more complicated than others, and I felt like there may be more of the old fluid left behind than when a conventional system is flushed. This would result in an unavoidable mixture of the old and new fluid.

You may be fine with another brand of DOT3, or even DOT4, but it is not clear that a different fluid would represent an "upgrade" and it carries some risk.

I used three 12-oz bottles, and felt it was barely enough. It all depends on how much you flush out during the process. After only 3 years, it was not perfectly obvious when the fluid color changed from old to new when bleeding it out, so I may have bled more than necessary. I found it useful to measure the volume of fluid that I bled out each time to avoid running dry and also to make sure I had enough overall.

Honda says the same thing about coolant right?

I think the only thing I know I must use OEM is the transmission fluid. Other than that, I fail to see what's special about OEM engine oil, oil filter, coolant, brake fluid or windshield washer fluid.

EDIT: After doing some further reading, apparently Honda Coolant is actually different? Who knew. I suppose you can always use Honda DOT 4 if you wanted higher boiling points and also stay on the good side of warranty claims.

 

[Landshark]

Honda says the same thing about coolant right?

I think the only thing I know I must use OEM is the transmission fluid. Other than that, I fail to see what's special about OEM engine oil, oil filter, coolant, brake fluid or windshield washer fluid.

EDIT: After doing some further reading, apparently Honda Coolant is actually different? Who knew.

Honda knew.

There is quite a variety of chemistries available in modern coolants. Choosing the wrong one, or using the wrong concentration, can be costly mistakes.

 

[megreyhair]

I would use the OEM coolant. You dont want to mix and match since they could be different between different brand even though 3rd party coolant from prestone,etc said they are compatible. My brother had to replace a radiator because he put in the wrong stuff to top off the reservoir and the radiator rusted and leaked.

 

[crvinva]

Did a brake fluid change with my friend in his 2021 Honda Clarity PHEV. We didn't know about the double-flush procedure (first with car ON and then again with the car OFF) at that time, so the car was off the whole time. Side note: why would Honda switch to rear 11 mm bleeder screws and put them in an awkward position facing up where they are harder to access (need a small wrench) and cause a bit of fluid spillage (just wipe it) is beyond me! When the car was turned on the dash lit up with a list of trouble indicators (just as other posters reported): Road Departure Mitigation System (RDM) problem, Adaptive Cruise Control (ACC) problem, Collision Mitigation Braking System (CBMS) problem, Hill Start Assist problem, Braking System problem, etc. Tried to read OBDII codes with one scanner I have and it couldn't see any. Driving the car was very sketchy: pulsating brake pedal, long stops, etc. Later in the day tried two other scanners (cheap ELM327 Bluetooth). Each one reported different/bogus error codes (ignition coil, glow plugs, etc.) but we tried erasing them anyway. Although it appeared that erasing the codes failed (we could read them again) when the car was turned off and on again a few things happened: the trunk popped opened, the fuel fill door popped opened, and all the problem indicators on the dashboard cluster display went away!
Main takeaway: expect all those errors when doing brake fluid replacement and using a basic OBDII scanner should be able to clear them. But you may need to find one which will be able to read/erase them. Also, be sure to turn the car off and on after erasing the codes.
Big thanks to everyone here who was brave to do this themselves and for helping others (including @MrFixit, @NorCalPete, and @gedwin). Especially to @gedwin, for describing "bizarre, weird pulsing, soft pedal and significant, unusual noises".
Knowing all of this doing brake fluid change in this car isn't very difficult and very glad we did it. I've been changing brake fluid every 3 years in all my cars anyway. And now we know how to do it in this car as well. Hope others will find this helpful.

 

[MrFixit]

Also, be sure to turn the car off and on after erasing the codes

Thanks for elaborating on your experience with this bizarre behavior. This particular thought has me wondering about codes / clearing, etc. Is it possible that looking for codes and clearing them (even though they seem irrelevant) is just a red herring? Maybe all that is required is multiple on/off cycles, Maybe the next brave person who does a fluid change could try to see if they can get these messages to clear without fiddling around with OBD codes...

 

[crvinva]

Is it possible that looking for codes and clearing them (even though they seem irrelevant) is just a red herring?.

I was thinking the same thing, and here's why: the next day (when all the problem messages on the dash were still gone and the brakes were working fine again) we used the same three scanners and results were identical to when problem messages were displayed. The ELM327 Bluetooth scanners were producing the same bogus trouble codes while another scanner reported no trouble codes at all again. I wonder if a fancier (Honda or aftermarket) scanner would be able to read and clear these (Honda-specific?) trouble codes sooner than waiting for some time or some number of car on/off cycles.
I didn't mention this in my earlier post but we used a two-person method of bleeding brake fluid, as described in the official Honda procedure.
Another thought: even though we had the car off during the entire brake fluid bleed process maybe the monitor system was still detecting abnormal pressures or low fluid level (in the master cylinder) during that time. And similarly, after the bleed procedure was done and the trouble codes we active, it took some time for the brake system to determine that everything is OK again, even while the car was turned off.

 

[JeffISU]

Did our brake flush today using the instructions posted here from the service manual (thank you!). First used a turkey baster (ok not really, a $6 syringe thing from Amazon) to suck out most of the fluid in the reservoir then fill with fresh. Started by doing the standard bleed at each wheel with car ON, driver->passenger->rear right->rear left. Then turned car off and left door closed for 3+ mins. Proceeded with pumping brakes to build pressure then bleed pushing pedal to the floor - did this 3x on each wheel and fluid was still clean coming out. Finished using just a hair under the 32oz Prestone DOT3 bottle, and had no codes/alarms on the dash.

 

[TC1782]

I did my 017 service yesterday and followed the same procedure as @MrFixit. Everything went as expected and the brakes work fine. But, like @MrFixit, the "Brake System" indicator was illuminated and didn't clear when I put the car in "On" mode and held the brake pedal for 3 seconds. I used both Vgate and Autel to check for error codes, including in the ABS/VSA and Electric Servo Brake System modules, but none were triggered. I turned the car off and on multiple times, drove it, and checked for error codes multiple times. I decided to wait a day to see if the indicator would clear. Today, the "Brake System" indicator was no longer illuminated. I think it's odd that the indicator was triggered without any error codes being recorded but, at this point, the job is done and everything seems to be fine. BTW, my tires seem to be holding up well: 25K miles with at least 5.5/32 of tread remaining on each one.

If I had to guess it was probably caused by the computer sensing an excessive amount of fluid consumption (basically that it has to move more to get the same braking effect). I've experienced a brake light too when taking my car on the track, when the brakes get stinking hot the pads get less effective, and the car will throw a brake light, but *not* a DTC. Cleared itself after the brakes cooled back down.

 

[NorCalPete]

Last month I did my second brake fluid change. This time I used Harbor Freight's "Pittsburgh Pneumatic Brake Fluid Bleeder with Auto-refill Kit" so I could do the job without needing someone to pump the brakes (which, last time, resulted in the "Brake System" indicator illuminating for a day or two). I had four 24-ounce bottles of Honda DOT 3 brake fluid, and used approximately a half-bottle for each caliper cycle. As indicated by Honda, I bled the calipers in order (DSF, PSF, PSR, DSR), first with the car "On" and then again with the car "Off" (and after letting the car sit for at least 3 minutes after turning it off). Using the pneumatic bleeder worked great, resulting in nice firm brakes without the "Brake System" illuminating afterwards. It was hard to see the fluid in the hose (the brake fluid wasn't that dirty), and the hose setup wasn't air-tight (there were lots of bubble), but it still was able to pull fluid through the system. As long as the master cylinder doesn't run dry, there is no chance of introducing air into the brake lines using this pneumatic bleeder. The kit's holder clip for the auto-refill bottle couldn't be used due to the overhanging cowl, but a bungee cord worked to hold the bottle in place. I set my air line regulator to 100 psi. As I discovered the last time I bled the brakes, the rear wheel fittings need to be unscrewed multiple turns before any fluid will be released. Overall, this process was much easier and quicker compared to the first time that I changed the brake fluid, so this will be my preferred method going forward.

 

[gedwin]

I did my MM 7 brake bleeding this past weekend (2019 base). I wanted first and foremost to thank previous posters in this thread! It was so very helpful to know 1) that two rounds of bleeding are required and 2) that error codes may appear afterward that must be cleared. Knowing both of these facts in advance saved me a lot of worry and helped ensure I did the job correctly.

The bleeding was mostly straightforward and conventional; I use the old school method of having a partner (i.e., son) press and release the pedal on command as I operate the bleed stems (10 mm wrench for the front, 11 mm on the rear). I chose to be in the "Ready" mode as my interpretation of "On" from the service manual. The first round of bleeding in this mode went fine until I was almost done with the final wheel, back left. During one of the presses, my son reported that the display screen lit up like a Christmas tree with 8 or so warning about systems failings and also he said that the brake pedal feel changed noticeably for his future presses. (No reason for this to have triggered at that particular point; I had been careful to keep the reservoir topped off, so that wasn't an issue.) Since I had already felt I was done at that final wheel (clear fluid), I had him do one or two more presses for good measure, then considered the first phase done. We turned the power off, waited as instructed, and then did the power off bleeds without event.

When I had everything back together, I powered on and noted all the systems-are-off warnings and dash lights remained activated. Press and hold brake pedal did nothing. I attempted to drive (backing out of the garage), and braking was bizarre: weird pulsing, soft pedal and significant, unusual noises. This is where I was so glad to have read previous posts here, otherwise I would have been panicking that I had ruined my car! But, armed with that foreknowledge, I plugged in my OBDII scanner and read codes P1E52 and P25A2. I cleared these codes, powered down the car, and then powered on again. Everything thankfully appeared normal on the dash, and a test drive verified normal braking.

I'm concluding that some specific event/condition during the system-on phase of bleeding triggered the errors. So, I imagine it is possible to complete the system-on bleeding without triggering the error codes, either through luck or by eventually figuring out exactly what type of brake press motion can trigger the sensor involved. But, in any event, I think this explains why it can be a hit-or-miss experience; I expect some people could bleed successfully without having any trouble at all. I am not sure if my DTC codes (P1E52 and P25A2) are the same/equivalent to what others have had.

3 years later, I did the brake bleeding again yesterday. This time everything went smoothly, no issues whatsoever.