Mushy Brakes
 

So I recently replaced my pads (winmax w2), rotors (centric premiums), and flushed the fluid (Motul 660). The brake pedal felt great after. Except 2 weeks later, my brake pedal definitely got softer.

It doesn't have the bite it did at the same pedal travel like when I first replaced them. I did the brake refresh a few months after a track day. During the track day I was using the oem pads (36k miles) and Motul 660. The brakes were really mushy after that day and they never firmed up much after. It still stopped the car fine but I had to push the pedal a lot more than normal. When I was flushing the fluid, I think the rear right caliper had a lot of air in it but it was hard to tell through the hose I was using to bleed. I was unable to bed them in properly as well so that might be an issue.

I cleaned and lubed the caliper pins, clean the caliper mounts, pad hardware, and around the caliper piston (did not use any chemicals on the piston, just wiped up the built-up dirt with a rag as best I can). Did not notice any leaking from the piston when I was retracting them.

Possibly I have a leak somewhere like the lines or the piston seals. The fluid level in my reservoir is still solid at the full line however. I'm going to bleed the brakes again this weekend and check over my brake system to see any damage, leaking, or uneven pad wear.

What are your guys take on this?

Same issue. Subbed


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Now that sounds like a good plan to me - :)


humfrz

Air in the system...

For me, I did that. Went to a PDX. Brakes were soft and mushy afterwards.
Next step for me is to put the W3’s back on and flush my brake fluid.
Now, when I bled the brakes, I did note that not a lot of fluid was pushing thru. Ill make a point to have clear tuning and such to see how much air may be in the lines.



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Change to a better brake fluid. Project Mu Gfour-355, Castrol SRF or Endless RF650. Motul degrades quickly and does not recover. It will feel good at the beginning and eventually lose pedal feel.

Socal 86Cup members use Project Mu Gfour-355 with no issues the whole season. Members who used Motul always complained of pedal going mushy and bleeds after couple of trackdays.

Also, if you do trackdays, Winmax W5 would be minimum pad recommendation :)

Feels like it but not sure how. These are my daily pads and only drove on the streets normally for the 2 weeks since I changed them.


Agreed. These are just my daily pads though. Not sure if my pedal going really mushy after the track day with my old brakes setup is related to my current brakes going a bit soft. Small leak letting air in and never recovering? I doubt I overheated the fluid. People say it should firm up after a few days but mine never firmed up much. Or it could just be the nature of the fluid like you described. It sounds similar but it happened after one track day for me.

That’s the way I was going. The Motul 600 has been in all year, AX at least once a month. I’m running G Loc pad, the R6. I’m not a heavy track guy, one of the slower ones so not that hard on the brake, yet. Planning on some more track specific pads. Waiting on a rotor/BBK change. Probably go back to Ferrodo or stick with the Winmax.


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I went over my brake system and there doesn't seem to be any leaks. I rebled using the two man method and noticed after the first pump and release of fluid, with the subsequent pump, the brake pedal was hard like the booster was pressurized. Basically, after the first pump and release of bleeder, I close the bleeder, then release the brake pedal, I push down on the pedal to pump pedal but it is hard with little to no travel. Is this normal or a symptoms of a problem? I've only used a vacuum bleeder recently and can't recall if this was how it was with other cars I've bled using the two man method years ago.

Other than that, maybe it's all in my head at this point or the pads as I was unable to bed properly. I'll see what happens to my fluid level and pedal feel in a few weeks.

Well, I think I figured it out. I over torqued the bleeder screw so it had a slight leak in it. I bled the fluid and bought new bleeder screws and it feels like it used to. Hopefully, I only damaged the bleeder screw and didn't mess up the calipers. I guess I'll find out in a week if it holds.

Just realized I drove on the track like this lol. That explains the terrible brakes that never firmed up after.