underrated99si

Ran my ITR at Laguna seca this weekend and faught a spongy peddle and lack of feel/ bite that I'm used to in the car.

Brake set up
- OEM calipers
- carbotech xp12 F. Xp 8 R
- brembo 600 fluid
- stoptech cryo treated slotted rotors
- SS lines up front
- OEM lines out back ( I know. fixing this week)

Bled the brakes prior to event. After day one I had a HT member Jackson help me bleed again thinking I had air in system. Prob did not resolve granted we didn't completely drain the system maybe a oz or 2 per caliper and tapped calipers to see if we had some air. Didn't see any bubbles.

Went out for three more sessions and 3rd session it for worse to the point where I called it a weekend after a close call braking for the corkscrew.

Today unloading at the house I decide to drive down the street brakes still crap and makes noise like metal to metal but not that race pad squeak.

Pulled front calipers pads have a lot of life left but did notice that rubber seal around the piston on one caliper to not be flush about 1/4 of it. It looked as though it was not ripped and could easily be put back.

Looked at brake master cylinder and where it meets the booster something at one point leaked a little but no fresh and very very little definetly not from the weekend.

So I'm stumped. Thinking of bleeding the brakes and making sure buddy is not on facebook when he is working the peddle and seeing if its just air. If not gonna replace master cylinder and booster.

Sorry for long post any help would be great thanks

- chris

RacerZook

iTrader: (1)

Have you ran the xp12s at laguna before? Thats quite a high temp pad. They might not of gotten to operating temp. I run the xp10s because my style and weight of the car never got enough heat into them to feel good.

underrated99si

Never run Laguna before. But its kinda like California speedway a couple of hard braking spots and the rest is point and shoot.

The pedel feel was off even off the trailor just felt spongy. Not the stiff pedel I'm used to with lots of feedback. Kinda like a truck pulling a trailor and your brake controller was set to light and u have to apply brakes a lot more. Best way I can describe it

RacerZook

iTrader: (1)

I wanted to try something different next time i bled my brakes. Maybe others can confirm or deny this trick.

I was helping my brother bleed the brakes on his yamaha r6. When i thought we were done, he zip tied the brake lever to the grip as much as he could, then left it overnight. The theory is that it would leave the ports in the mc open so air could escape back into the resivior. There was a considerable amount more pressure the next morning.

I wanted to try this on my civic, but not sure how to keep pressure on the pedal overnight. Maybe one of those anti theft devices that actuate off the brake pedal? Might be worth a shot.

CW-ITR

iTrader: (11)

I haven't gone to track this year. But, my brake acted similar to your on the street. It turned out that the master leak fluid from the cabin side. New one is on the way.

underrated99si

So the master cylinder not the big giant brake booster it attaches to? I priced them both out hoping its just the master that's $200 the booster is almost $700

RacerZook

iTrader: (1)

Maybe check the one way valve on the booster. Could be leaking vaccuum or failing there.

red0

I have all of this if you want it cheap. I recently bought an ITR front clip just for the engine + trans.

$225 for the booster assembly and the brake master assembly?

Honda Type R

Underrated, I had a similar issue with the clutch system on my car. No matter how much I bled it, the pedal never got stiff. Ended up being a blown slave. The slave was letting air in little by little. When you change the rear lines give it a good thorough bleed. Also, for the master, check out Importrp.com They sell the OE master for 115ish.

Honda Type R

If your calipers are all dry, pull the master off of the booster and see if it's wet at all. If there's even a drop of fluid, replace the master asap

underrated99si

Honda R: ya replaced my cluch master last year it dripped fluid on the inside of the fire wall.

Thanks for the brake master deal that's a smoking price.

Lo-Buck EF

underrated99si- if you are sure you got all the air out and your pedal is still spongy (not firewall flex), you need a master. when they leak, they leak fluid down the booster and it usually shows itself by a rust trail down the front of the booster.
if the booster were bad, you would have a hard pedal because the booster wouldn't be adding boosted brake pressure (via the vacuum) and you would be closer to manual brakes.

underrated99si

Good info lowbuck. That's makes me feel better. Pretty sure all the air is out and there is a small small dry residue kinda like hard water stain that looks like a small leak at one point was present at the master and booster connection. Gonna put on new SS lines and new master when I come back from my fire assignment.

sxysweed

I see no reason why this would work.

Ports in the master are open when the pedal is released, that's why the brakes release and why you can gravity bleed brakes. Pinning the pedal to the floor will close the intake ports to the reservoir and leave the ports leading to the lines open. Ports will be open leading to the lines regardless, so air would be able to theoretically filter up regardless (though this never really happens).

If you're doing brake work and need to leave the system open for an extended period, you can prop the pedal down to prevent liquid from running through the system (that way the master stays full and you don't need to worry about bleeding that). But you'll still get air in the lines when you release the pedal, as the master will 'suck' the fluid back up.

Pad material can effect pedal feel. Think about it, if the pads aren't warm enough, they won't grip the rotor and you'll need to step on the pedal harder to stop. Perhaps imagine it as being absolute bottom dollar parts store pads that suck vs. a good street pad. Look at the graph (consider it generic lines, don't focus on what pads are comparable to what you have): Some pads don't do crap when cold compared to other pads.