took my car to a local shop to have new front tires mounted, and next day my brake pedal is "soft" and goes straight to the floor with minimum brake response.

since this happened i have: inspect level of brake fluid, full. visualy inspect brake line for any leaks, light sheen of brake fluid on/around "proportioning valve". after this i proceed to remove all 4 tires and bleed the hydraulic system. i bleed the corners rr, lf, lr, rf, as outlined in the manual as well as numerous threads.

from the first "bleed cycle" i get solid pressure on rr and lf with a good amount of fluid moving through, while having almost no pressure/very little fluid moving through on lr and rf.

anyone had similar issues? thanks

 

clif notes: half my brakes work. im stumped. search option exhausted

 

Given that the brake pedal fell to the floor and specific brakes don't pressurize, I think you master cylinder has an internal failure. There are two brakes lines that run from the master cylinder to the dual proportioning valve. One line serves the left rear and right front brakes (your problem). The other line serves the right rear and left front brakes.

 

thank you RonJ!

just the info/diagrams i was looking for. i will inspect/remove/replace as necessary and post results. yes!

there was a lot of debris coming out during the initial bleeding, could be blocking up my m.c.?

 

update: i siphoned off the remaining fluid in the m.c.. 1-3mm pieces of debris were coming through the tube.

pic 1: filthy fluid reservoir

pic 2: i hooked up a small vacuum attachment and sucks all remaining fluid and debris out of m.c.

pic 3: so clean

the goal is to get my brakes working and not drop hundreds on new parts

 

another update:

re-bleed brakes. still no pressure to RL and FR brakes.

so the master cylinder is bad i guess. before i go buy one though, any chance it could be the proportioning valve?

 

Is the pedal still soft or spongy?

 

try cracking the lines at the master if there's pressure then look at the prop valve (never seen a honda valve fail) but i think you need a new master all that junk proably wreaked a seal

 

RonJ - yes, still as spongy as when i began troubleshooting

canadaek - i think you're right. i was under the impression that anything in the brake fluid would wreck something and i had a ton of stuff.

back to the auto parts store i suppose

 

Buy a new master cylinder.

 

final update:

bought a new(not remanufactured) master cylinder 47.99. bench(lap) bled it in my driveway. installed as the sun was going down.

also picked up a 5.99 bleed-o-matic from harbor freight. bled all 4 corners in the dark.... 5.99 for a bleed bottle, and bleeding hydraulics becomes fast and easy even in the dark

PROBLEM SOLVED, for about $60.

picture: fresh master cylinder.