So from what ive read around the forums pertaining to the mushy brake pedal everyone has been having especially with the 2nd gen tl and lots of people seem to be having this problem as well as me, and after almost a gallon of dot 4 brake fluid flushes and bleeding lmao it didn't go away, well the brake pedal would firm up right after the bleeding but slowly come back, so now from what i gather after eliminating almost all other sources of leaks etc. i stumbled upon what could some people have said could be the culprit being the abs modulator leaking air back into the brake system, and it seems as tho air is some how getting in, so after 15 mins of looking around for more leak around the abs modulator i thought hmmm you know these little holes on the abs modulator body are plugged up by little bbs and some kind of plastic seal, so i thought to myself maybe the air is leaking in through them, i know that the holes themselves were drilled in order to have galley ways in the production of these things and then plugged back up with usually bb's or hex plug machine screws, but in this case acura chose bb's so i went ahead and cleaned up all the little sand and dirt debris from them the best i could with brake cleaner and a toothbrush, after that i plugged up the face of the bb holes with some gasket sealant, then i proceeded with bleeding the brakes one more time front driver/pass/left/right rear, and in a nut shell walla!!! no more squishy soft brake pedal action, so for those who dont want to spend lots of molla on a new abs unit from the stealership this is a great, and easy fix. Dont forget the ones on the sides on both sides, And also on another note it seems as if lots of people are having alot of dull knocking noises from there engines, so i ask has anyone suspected wrist pin noise as the culprit? i know it's not my rod bearings cause i just installed new ones with proper plastigauge clearances, the noise is soo disconcerting.

 

Although that isn't an issue on all 2nd gens, Type-S don't share the same ABS modulator with the TL-p so they don't have this issue.
But that's nice to know! Congrats on fixing your issue.

 

did I read you did the bleed as: LF RF then you did Left rear then right?

Its driver front then clockwise around the car LF RF RR LR
Important to do it only in that order

NOTE: if you disconnect a brake line to replace the line or caliper,
you MUST do 2 ABS active full stops from 45 mph, if the 2nd time had firmer pedal you had air in the ABS and now its in the regular system waiting to be bled out
It happens~

Rebleed LF RF RR LR and it should be good to go!

note2: Acura says flush the brake fluid EVERY year- max between flushes is 3 years!
It may look ok but the bad stuff -ie: moisture has been compressed and moved down to the caliper = bad news for brake pressure and parts life

 

Caution on bleeding using a 2 man pump and hold pedal method- do NOT allow the brake pedal to go all the way to the floor when bleeder is opened!!

Past its design limits for the critical seal inside, will ruin a good master cyl simply by bleeding wrong!

It takes about 1.5 qts to do a great job flushing the TL brake fluid