Soft Pedal Solutions - Rd. 2
Oct 17, 2016, 07:23 AM
#1
Soft Pedal Solutions - Rd. 2
Thought it'd serve best to make a separate thread for this.
Had a track day in July where I destroyed my brakes and they have never been the same since. It's not the bite that's not there, but it's just mush on the pedal. I have done the following:
Hoping to hear if anyone's got any ideas on what else to try. I'm mulling swapping out the pads again/trying the brakes without the titanium shims, or also trying a new brake booster. I realize bad boosters typically result in harder pedals, not softer ones, but I'm getting an intermittent popping from mine as well when bleeding brakes manually. By the time I replace that though, I'll have pretty much replaced the entire brake system on this car.
Before we get too much into it, though others (cough, Eric) will swear that I'm not bleeding the brakes right and I still have air in the lines, I'm almost positive now, by the literal gallons of brake fluid I've gone through, that I do not have any more air left in the lines.
One thing I thought was curious when I swapped the BMC - the paint in the area around the brake booster that makes contact with the BMC is flaking off from what looks like contact with brake fluid. Theoretically possible it's seeping by, more so probably from the old BMC, but it shouldn't be. I have heard brake fluid can collect in the booster if it goes bad though.
::Resolved! Check your shims!
Had a track day in July where I destroyed my brakes and they have never been the same since. It's not the bite that's not there, but it's just mush on the pedal. I have done the following:
- New pads. Girodisc S/S pads with titanium shims, all 4 corners
- Flushed brake fluid probably 15 times now since July, both 2-man and pressure, and yes in the correct order & both sides of the caliper
- After that didn't work, I replaced the brake master cylinder. Didn't fix it. Yes I did bench bleed it.
- Installed Grimmspeed brake master cylinder brace. Didn't fix it, but did feel a lot firmer. Already have stainless brake lines since before all this
- Installed new front calipers with stainless steel pistons & high temp seals. Flushed several times now, and the pedal is still mush, nearly the same as before I changed calipers.
Hoping to hear if anyone's got any ideas on what else to try. I'm mulling swapping out the pads again/trying the brakes without the titanium shims, or also trying a new brake booster. I realize bad boosters typically result in harder pedals, not softer ones, but I'm getting an intermittent popping from mine as well when bleeding brakes manually. By the time I replace that though, I'll have pretty much replaced the entire brake system on this car.
Before we get too much into it, though others (cough, Eric) will swear that I'm not bleeding the brakes right and I still have air in the lines, I'm almost positive now, by the literal gallons of brake fluid I've gone through, that I do not have any more air left in the lines.
One thing I thought was curious when I swapped the BMC - the paint in the area around the brake booster that makes contact with the BMC is flaking off from what looks like contact with brake fluid. Theoretically possible it's seeping by, more so probably from the old BMC, but it shouldn't be. I have heard brake fluid can collect in the booster if it goes bad though.
::Resolved! Check your shims!
Last edited by kyoo; Dec 7, 2016 at 01:33 PM.
Oct 17, 2016, 09:36 AM
#2
EvoM Guru
iTrader: (1)
Brake fluid will collect in the booster only if the master leaks fluid into it. The brake fluid would then eats away the diaphragm until the booster is ruined. But a bad booster makes a hard pedal, not a mushy one.
Does the pedal suck when you pump it in the driveway, or only when driving?
Does the pedal suck when you pump it in the driveway, or only when driving?
Oct 17, 2016, 11:43 AM
#3
Brake fluid will collect in the booster only if the master leaks fluid into it. The brake fluid would then eats away the diaphragm until the booster is ruined. But a bad booster makes a hard pedal, not a mushy one.
Does the pedal suck when you pump it in the driveway, or only when driving?
Does the pedal suck when you pump it in the driveway, or only when driving?
Oct 17, 2016, 12:01 PM
#4
Figured I'd reply in here so others can see my train of thought vs us going back and forth via email. I still don't think there is anything mechanically wrong with the car. Booster wouldnt make the pedal soft, and if your lines were bad you'd know it. Theyre teflon lined and encased in braided SS. The whole concept is such that the SS doesnt allow them to expand much at all hence the stiffer pedal feel. So the only way the pedal could be soft given that its the lines is if its bulging which I dont see being possible in your case.
I know I keep telling you and I think and you probably want to smack me in the head at this point (not needed don't worry I hit my head enough without you!) but keep bleeding. Old fashion 2 person bleeding. It sucks, yes. Brake fluid sucks, yes. Your gf getting annoyed with you sucks, yes.
But your brake pedal ED sucks more than all of that. So get back out there and keep bleeding and get her stiff again.
I know I keep telling you and I think and you probably want to smack me in the head at this point (not needed don't worry I hit my head enough without you!) but keep bleeding. Old fashion 2 person bleeding. It sucks, yes. Brake fluid sucks, yes. Your gf getting annoyed with you sucks, yes.
But your brake pedal ED sucks more than all of that. So get back out there and keep bleeding and get her stiff again.
Oct 17, 2016, 12:33 PM
#5
understand what youre saying, and likewise to discuss "publicly," what are we suspecting here? a big bubble, small one, clusters? Every time I bleed the probability of air being stuck is getting smaller and smaller.
good point on the ss lines. what they're saying is, harkening to when I wore my brake pedal to nothing, that the metal on metal contact could have damaged the inner Teflon of the SS line. I don't understand how that makes sense, save for a heat issue, but I did have to drive around quite a ways without a brake pad on one side.
--
just as an FYI, my lines were Russell SS lines. not sure if those are good or bad but they've been subjected to boiling brake fluid more than once now, and brakes on fire once as well. the theory on what they're saying re: ss lines failing is where the inner liner fails, and rather than it bulging, it can collapse and expand, causing the pedal feel. inner liner also provides resistance to expansion as well, and could expand a little under pressure. looking at AMS ss lines unless you guys say otherwise... I'm loving how clean my new calipers are, so I'm thinking of getting the rears done as well, just for vanity, not to fix the brakes. if I do that, I practically might as well get new lines....
good point on the ss lines. what they're saying is, harkening to when I wore my brake pedal to nothing, that the metal on metal contact could have damaged the inner Teflon of the SS line. I don't understand how that makes sense, save for a heat issue, but I did have to drive around quite a ways without a brake pad on one side.
--
just as an FYI, my lines were Russell SS lines. not sure if those are good or bad but they've been subjected to boiling brake fluid more than once now, and brakes on fire once as well. the theory on what they're saying re: ss lines failing is where the inner liner fails, and rather than it bulging, it can collapse and expand, causing the pedal feel. inner liner also provides resistance to expansion as well, and could expand a little under pressure. looking at AMS ss lines unless you guys say otherwise... I'm loving how clean my new calipers are, so I'm thinking of getting the rears done as well, just for vanity, not to fix the brakes. if I do that, I practically might as well get new lines....
Last edited by kyoo; Oct 17, 2016 at 12:47 PM.
Oct 17, 2016, 12:44 PM
#6
When you get home from work one of your tasks is to inspect every brake line. I highly doubt one failed or is failing but look anyway to cross it off the list. If the teflon liner is worn down enough to bulge the braided SS would still keep the line from bulging anyway I'd think. Now if the liner were to completely fail then you'd have a fluid leak as the SS braids aren't fully sealed.
So once again Im not seeing how this is a mechanical failure. I don't recall how to trigger the ABS to get all the potential air out of that module thingy but search as I know its been posted before. Other than that just think its pesky air bubbles. Been there and done that. I've wasted way too much of my time bleeding sh*t. Did the same thing with my ACD pump when I relocated it. It sucks and the whole time youre thinking something must be wrong; it can't possibly take this long. But stick to it and I think you'll find more air and eventually you'll end up where you want to be.
Don't give up never give up!
So once again Im not seeing how this is a mechanical failure. I don't recall how to trigger the ABS to get all the potential air out of that module thingy but search as I know its been posted before. Other than that just think its pesky air bubbles. Been there and done that. I've wasted way too much of my time bleeding sh*t. Did the same thing with my ACD pump when I relocated it. It sucks and the whole time youre thinking something must be wrong; it can't possibly take this long. But stick to it and I think you'll find more air and eventually you'll end up where you want to be.
Don't give up never give up!
Trending Topics
Oct 17, 2016, 01:07 PM
#8
EvoM Guru
iTrader: (1)
Have you actuated the ABS? Sometime air can get stuck in the module, and the only way to get it out is to drive the car, get it to activate, then rebleed.
Oct 17, 2016, 01:16 PM
#9
Yeah I was thinking the ABS module was a potential for air be be trapped. But even then I doubt that's the case here given the fact that calipers were pulled so it seems the air simply got into the system that way. I suppose it can work its way up in there however.
I thought I recall a thread in the past with a how to on triggering that to open up for bleeding? I'll see if I can find the thread at some point as I thought it was fairly straight forward and wasnt something where you need a friggin Snap on Solarus scanner or anything fancy like that.
I thought I recall a thread in the past with a how to on triggering that to open up for bleeding? I'll see if I can find the thread at some point as I thought it was fairly straight forward and wasnt something where you need a friggin Snap on Solarus scanner or anything fancy like that.
Oct 17, 2016, 01:27 PM
#10
Just scanned this thread: https://www.evolutionm.net/forums/ev...-bleeding.html
See the air is a giant PITA and you're not alone. Whats interesting is people talk about bleeding with the car running. Ive never done that. What's the benefit to that?
A guy posted and mentioned that if you have the car up in the air put it in gear and start driving and then hit the brakes ABS will kick on bc all the wheels lock up the system freaks out and opens up all those valves. So that seems like a simple way to activate the ABS.
See the air is a giant PITA and you're not alone. Whats interesting is people talk about bleeding with the car running. Ive never done that. What's the benefit to that?
A guy posted and mentioned that if you have the car up in the air put it in gear and start driving and then hit the brakes ABS will kick on bc all the wheels lock up the system freaks out and opens up all those valves. So that seems like a simple way to activate the ABS.
Oct 17, 2016, 01:37 PM
#11
I usually bleed, activate ABS, and bleed again. cumbersome I know but I figured I'm constantly bleeding anyway. i'll do a fourth bleed post-caliper install later this week, maybe on Saturday. I'm sure there are still a handful of bubbles meandering about.
