LS 4-piston Brake setup for my SC4
07-12-09, 07:34 PM
#196
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Alright got my LS brakes on pedal is spongy seems to be a common issue. Is this a solvable problem, or just have to deal with it issue? All the old brake fluid was bled out and new was added in. Bled twice by machine, new pads new rotors, SS lines. Rears are still stock, but also new pads and SS lines.
07-12-09, 10:28 PM
#199
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THat's just odd to me, having to rebuild 11 year old calipers. I had a 96 integra and never had to rebuild the caliper, my stocks are 12 years old and don't need a rebuild. Just weed, but thanks for the info I'll keep it in the back of my bad if push comes to shove and that's the only option that I haven't don't then I'll do it
07-12-09, 10:42 PM
#200
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If they aren't stuck then there's no reason to rebuild. Can't see how that will eliminate mushiess unless you got them burned up to begin with.
It sounds like these calipers bolt up, but the MC in the our cars isn't big enough to supply fluid to this caliper- piston area for the MC is probably too small. Henceforth the mushy pedal -
Tell me, is it a longer stroke to engage the calipers? You may stop when you mash the pedal, but it's a long, mushy feel and your brake feel (modulation) is probably for schit now..
Frankly it sounds like a different MC is required for this to work properly..If this is the case why would anyone want to do this? It's unsafe.
I'm honestly curious, not a flame - it sounds like more times than not this winds up with mushy pedal, and some of you have gone to some extreme measures to make sure there's no air in the system.
Has ANYONE done this mod without creating a weird pedal? Meaning, if you were not trying to panic stop does it feel like stock?
It sounds like these calipers bolt up, but the MC in the our cars isn't big enough to supply fluid to this caliper- piston area for the MC is probably too small. Henceforth the mushy pedal -
Tell me, is it a longer stroke to engage the calipers? You may stop when you mash the pedal, but it's a long, mushy feel and your brake feel (modulation) is probably for schit now..
Frankly it sounds like a different MC is required for this to work properly..If this is the case why would anyone want to do this? It's unsafe.
I'm honestly curious, not a flame - it sounds like more times than not this winds up with mushy pedal, and some of you have gone to some extreme measures to make sure there's no air in the system.
Has ANYONE done this mod without creating a weird pedal? Meaning, if you were not trying to panic stop does it feel like stock?
Last edited by RANDY P; 07-12-09 at 10:48 PM.
07-12-09, 10:50 PM
#201
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The MC is what I was thinking because of the bigger calipers. Also is there a proportion valve, could that be it also if there is one? It's just a WAY long stroke before it engages, but once it does it bites hard.
Reason I ask about a proportion valve is when I did a ABS delete on my Integra I had to swap out the proportion valve from a non ABS integra, but not the MC
Reason I ask about a proportion valve is when I did a ABS delete on my Integra I had to swap out the proportion valve from a non ABS integra, but not the MC
07-12-09, 11:17 PM
#202
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I've seen this before - on Porsche 911 dudes swap in calipers off a 930 turbo and unless you swap the MC this is what happens exactly...
The only cure was the larger piston area off the 930 MC, or the MC off a Mercedes delivery truck...
rjup
The only cure was the larger piston area off the 930 MC, or the MC off a Mercedes delivery truck...
rjup
07-12-09, 11:30 PM
#205
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The plan is to do one more bleeding tomorrow, and doing some weird trick that involves the ebrake while bleeding (don't ask, I'm curious myself), my cousin claims he has done this on other cars so we'll see, something with pushing the fluid back to the front and something something. Ill let you guys know what's up! If that doesn't work it's gonna have to be the MC. If someone reads this and has done the swap and got rid of the long pedal travel or never got the pedal travel please chime in.
07-13-09, 07:22 PM
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It's not fluid capacity, it's fluid displacement vs. stroke. A larger bore MC will increase fluid movement per distance traveled (stroke), shortening the stroke required to engage the calipers.
Swapping the rears isn't gonna do anything to this issue, just make it worse.
2nd thing, these are ABS cars,stopping distance isn't going to improve since the braking threshold is limited by ABS operation- in stock form we can kick in the ABS anywhere, anytime- so "Bite" isn't really a valid observation. The only possible gain is increased thermal capacity (the amount of use before brake fade kicks in) and that's only applicable during track use.
Really, is there anyone out there tracking the car hard enough to require this?
Swapping the rears isn't gonna do anything to this issue, just make it worse.
2nd thing, these are ABS cars,stopping distance isn't going to improve since the braking threshold is limited by ABS operation- in stock form we can kick in the ABS anywhere, anytime- so "Bite" isn't really a valid observation. The only possible gain is increased thermal capacity (the amount of use before brake fade kicks in) and that's only applicable during track use.
Really, is there anyone out there tracking the car hard enough to require this?
Last edited by RANDY P; 07-13-09 at 07:26 PM.