Front brake master cylinder recall

[Cmeadows270]

Had the recall done on 2022 busa for the front brake master cylinder this past Saturday… the lever still feels spongy the shop said they bled it and bled it and that I need to take the cover off to the resivoir and pull the lever in and zip tie it and let it sit for 24 hours and whatever air that is left in the system will make its way out… anyone heard of this? Any suggestions?

 

[Dustin02]

Yes, that happens sometimes. I always bleed my clutch side like that.

 

[sixpack577]

Yes, I always do that too...but the lever is not spongey before hand either.
I would question if they know how to properly bleed ABS brakes.
Both exit line bolts on the ABS pump need to be opened/closed and bled like bleeder screws, if they did not actuate it with Suzuki software.
The zip-tie trick Does get all of the air out, but as said, you should still have good brake pressure before hand.
Something isn't right.

 

[Hayabusa Wannabe]

The zip-tie trick Does get all of the air out, but as said, you should still have good brake pressure before hand.

@sixpack577 would not pressurizing the system via tying the controls dissolve the air in the ABS and allow it to be purged at a bleeder? Or why not?

 

[sixpack577]

@sixpack577 would not pressurizing the system via tying the controls dissolve the air in the ABS and allow it to be purged at a bleeder? Or why not?

When you tie the lever or weigh down the pedal for an extended period of time, the constant pressure causes any air in the lines to move to the ends of the lines/the bleeders, and then opening/closing the bleeders gets the rest of the air out.
If you do this on an ABS system, and have not bled the ABS pump, then you will still have air trapped in the line inside the pump, which is why the both of the ABS pump's exit lines must be bled like they were bleeder screws, then bleed the master cylinders, then bleed the calipers.
Otherwise you cannot get all of the air out.
If you bleed the front calipers, then the front MC, and the fluid level in the resivor drops, as it should...but then rises again when you release the lever, that is air in the line between the front MC and the ABS pump.
So, to the OP, bleed each front caliper once, you should have minimal to no air, then bleed the front MC(it has it's own bleeder screw, but MC's that do not can again simply use the line bolt, and open and close it as a bleeder).
The MC should bleed with minimal to no air(the very tiny pinhead size bubbles that are always present are from air sucking past the threads on the bleeder screws, and are normal), but if the fluid level in the MC resivor rises when you release the lever, you have found the problem...air in the ABS module, as it is pushing the fluid in the exit line from the ABS pump back to the MC.
For ABS brakes, I bleed the calipers first, the MC's next, and the ABS pump exits last, so that the lines get full of fluid.
Then I reverse that order, and bleed at the exit lines at the ABS pump first, then the MC's, then the calipers, to move all the air out.
Then I zip-tie the lever, hang a weight from the pedal, wait a couple hours or overnight, then bleed the calipers again.
Assuming it was bled correctly the first time, each caliper may or will have the smallest amount of air left, close the bleeders, and it's done.
You shouldn't even have to add fluid to the resivors either.

 

[sixpack577]

@sixpack577 would not pressurizing the system via tying the controls dissolve the air in the ABS and allow it to be purged at a bleeder? Or why not?

And the air cannot disolve, as it is in a closed hydraulic system with nowhere to go, as well as the fluid will absorb the moisture that was in that air, which is why the air must be bled out from the end points of the system, which is the calipers, but again, if air is trapped at the ABS module, it has nowhere to go.
Air also compresses, which is where the 'spongey' feeling comes from, vs hydraulic/brake fluid/a liquid, which cannot be compressed.

 

[Cmeadows270]

Yes, I always do that too...but the lever is not spongey before hand either.
I would question if they know how to properly bleed ABS brakes.
Both exit line bolts on the ABS pump need to be opened/closed and bled like bleeder screws, if they did not actuate it with Suzuki software.
The zip-tie trick Does get all of the air out, but as said, you should still have good brake pressure before hand.
Something isn't right.

So assuming they didn’t do this.. would I have to start the process of bleeding the front brakes and if so in what order would the abs pump be ?

 

[MonkeyButtRides]

You probably already know this but for the record, the master cylinder recall was to fix a brake malfunction not the 'spongey' feel. I had numerous instances where the lever completely blew through all the way to the grip with no resistance at all. Post recall, I haven't had that issue. All that said, the overall feel of the lever is about the same before and after the recall for what it's worth.

 

[sixpack577]

So assuming they didn’t do this.. would I have to start the process of bleeding the front brakes and if so in what order would the abs pump be ?

Personally, since you have brakes and know that the lines are full of fluid, I would still bleed each front caliper once, and expect little to no air to come out.
I would then bleed the front MC, and not be suprised to see the resivor level rise when you release the lever.
If the fluid level does not rise, great, but that doesn't mean that the line between the pump and mc are air free, but that it isn't a huge air bubble.
Then bleed the exit line bolt going to the front MC, by opening and closing it like it were a bleeder screw.
Wrap a rag around it to prevent brake fluid from leaking into the bike.
You should hear a small spit of air when you loosen the line bolt(as the lever is pumped and held closed just like you were bleeding a caliper).
Then bleed the MC normally, and then bleed both front calipers.
Next you can bleed the rear in the same order.
Even though the ABS braking is linked, the front and rear do not share hydraulic lines, and get bled independently of one another.
So air in the front lines cannot get into the rear lines, and vice versa.

 

[Cmeadows270]

Yes, I always do that too...but the lever is not spongey before hand either.
I would question if they know how to properly bleed ABS brakes.
Both exit line bolts on the ABS pump need to be opened/closed and bled like bleeder screws, if they did not actuate it with Suzuki software.
The zip-tie trick Does get all of the air out, but as said, you should still have good brake pressure before hand.
Something isn't right.

Nevermind I see the answer to my question in you other reply .. thanks man

 

[sixpack577]

Nevermind I see the answer to my question in you other reply .. thanks man

Yes sir
Good luck with it, and let us know how it turns out.

 

[sixpack577]

Had the recall done on 2022 busa for the front brake master cylinder this past Saturday… the lever still feels spongy the shop said they bled it and bled it and that I need to take the cover off to the resivoir and pull the lever in and zip tie it and let it sit for 24 hours and whatever air that is left in the system will make its way out… anyone heard of this? Any suggestions?

I also just caught this part where they say to "take the cover off the resivor" while you zip-tie it...which is not only completely unesacerry...but stupid advice, as brake fluid will absorb moisture from the air...which leads to air in the brake fluid.
These guys clearly do Not know what they are doing.