Brake firmness/pedal feel

[DarkSunrise]

Just before track days, I swap pads and do a full brake fluid flush. The pedal is nice and firm on the street after that.

Since those are pretty cheap/simple changes, I'd start there.

[CSG David]

Is there a reason why you would not want to change to the appropriate brake pads and brake fluid for your driving application? Dust? Noise? Zero babygurl factor?

[yomny]

OP- i have the same situation, is not horrible or drastic but i do feel that after the first pump it stiffens up. This is weird and normally this would indicate some sort of issue but being that my car is fairly new i left it alone. I bleed the brakes almost every two months, i find it it helps but maybe its all in my head. Maybe its got something to do with the engine vacuum or something around those woods. I've started to wonder if SS lines would help or maybe even upgrading the fluid but being that you get this with all stock components and i get it with upgraded ones, it seems as if its a car issues(not a problem).

I even removed the speed bleeders i had and went back to stock thinking those guys had something do with it. Odd but i think there's nothing wrong, just something related to engine vacuum or something being that the power brakes work with the brake booster.
@Hyper4mance2k

[wheelhaus]

I also notice the first pump feels a little soft, second pump feels really firm and responsive.. I am inclined to blame brake booster, but that's only because I can't figure what else might cause it. I have the Grimmspeed MC brace, and I still notice it.

[Hyper4mance2k]

Originally Posted by CSG David

Is there a reason why you would not want to change to the appropriate brake pads and brake fluid for your driving application? Dust? Noise? Zero babygurl factor?

LOL! Itz da babygurl.
Kidding, but to be honest. If there is a problem, I want it warranty fixed, and replacing fluid or swapping pads could void the brake warranty if the dealer decides that they were the cause of the issue.

I'm was also thinking the booster could have a slight leak.

[wheelhaus]

Originally Posted by Hyper4mance2k

LOL! Itz da babygurl.
Kidding, but to be honest. If there is a problem, I want it warranty fixed, and replacing fluid or swapping pads could void the brake warranty if the dealer decides that they were the cause of the issue.

I'm was also thinking the booster could have a slight leak.

Pads are pads, for the most part, if you took it in with some cooked racing pads or something they might have an argument. Even still, the problem is a soft pedal, not a leaking caliper seal. And fluid, as long as it's rated the same or better as OEM fluid they'd have no basis to deny it. Good Dot 4 fluid is all relatively the same amber color anyways, some a little darker (like motul is kinda dark IIRC).

The difficulty is proving that there's a problem in the first place. "Does the car come to a stop and can you activate ABS?" "Um, yeah, but it just doesn't feel ri.." "Then there's no problem. Kthxbye."

[CSG Mike]

Originally Posted by Hyper4mance2k

LOL! Itz da babygurl.
Kidding, but to be honest. If there is a problem, I want it warranty fixed, and replacing fluid or swapping pads could void the brake warranty if the dealer decides that they were the cause of the issue.

I'm was also thinking the booster could have a slight leak.

I've never heard of warranty being voided because you bled your brakes.

Since you've experienced brake fade in the car, it's probably safe to assume you've degraded your brake fluid, especially since the symptoms you describe exactly describe air in your brake system.

I'd recommend you bleed your brakes with a quality DOT4 once a year, and call it a day. You've been around race cars long enough; this should take you under an hour.

[Hyper4mance2k]

Originally Posted by CSG Mike

I've never heard of warranty being voided because you bled your brakes.

Since you've experienced brake fade in the car, it's probably safe to assume you've degraded your brake fluid, especially since the symptoms you describe exactly describe air in your brake system.

I'd recommend you bleed your brakes with a quality DOT4 once a year, and call it a day. You've been around race cars long enough; this should take you under an hour.

Ugh, but I'm old now and I have a broken baaaccckkk. I don't wanna do any work.

Thanks everyone. I think I'm going to bleed it this weekend and replace my fluid with some Torque RT700 and see how it goes.

[Metabrz]

Originally Posted by aegisdrgn

Was it really hot or did the track have lots of straights followed by braking zones/hard turns? You might have experienced expansion of the stock rubber brake hoses due to the heat in your brake system. Might want to try braided steel lines - you've improved almost everything else about your brakes, shouldn't leave out the communication lines between the driver and the brakes.

Hmmmmm, maybe I should invest in those SS brake lines. Yes it was hot, we've had one of the best summers ever here in NZ, unless you're a farmer and suffering from the drought then its a shit summer.

Hampton Downs has two long straights and also two hard braking zones into hairpins. Turn one is a 3rd gear 70mph corner coming out of 5th gear at 105mph. Turns four and five are hard braking into tight hairpins, one flat but the second one falling after a crest.

I first took instruction from a professional and his advice on these corners was "put the nose on the deck!!". I've taken that advice to heart at every track day I've been to since.

The car has an aftermarket MC booster.

I just noticed my right rear caliper has a dirty greasy residue on it after the track day (Toyota Festival 2015 BTW). I've just noticed it today. I'm still not driving the car as I blew up the rear right shock coming out of turn 3 and ran out of rumble strip - dropped it into a hole at 75mph.

I've attached a photo - its the black crescent shaped mark on the bottom of the caliper. Any thoughts from the experts? I'm thinking this might be brake fluid.

[wparsons]

Impossible to tell from the picture, but unless there is A LOT more of that on the inside of the caliper, it's not break fluid.

The pistons are on the inboard side of the caliper, so fluid would have to travel a long way to get to that part of the caliper carrier.

[Tgionet]

You say you blew up your right rear shock, I'd assume that and the fluid are related.

[Metabrz]

Originally Posted by Tgionet

You say you blew up your right rear shock, I'd assume that and the fluid are related.

I was thinking the same thing 10 minutes after posting.


Thanks for the input people.

[Tbird232ci]

Pedal feel is typically determined by rear brakes. With a floating caliper, the biggest cause of this issue is called pad kickback. Basically, while you're driving, the small amount the rotor moves, and the motion of the caliper while you're driving actually pushes the piston back in a small amount. Once your pads wear to say 60% or less, it's easier for the caliper to "walk" and push the piston in. That's what gives you that dead space.

In my experience, toss a set of pads on it, and you'll be good to go.

[donoman]

Brakes on my car are pretty good. Not Porsche good (I drive a 964) but not squishy like you're describing at all.