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Soft Pedal Solutions - Rd. 2

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Old Oct 26, 2016, 08:04 PM
  #31  
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all relevant bleeder valves have been replaced at this time
Old Oct 27, 2016, 07:10 AM
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Originally Posted by deylag
I have seen brake bleeder valves go bad. Either debris gets stuck inside the bleeder valve or air comes out through the threads on the bottom.

As old as the Evo is now valves and other similar parts should be checked before being put into use.
Im not saying you're wrong bc that is clearly prone to happening. But my only point and/or question was assuming the threads are weaker from usage over the years or there was dirt and crap in there, as long as they are sealed once they are tightened back down what's the big deal? If air is able to get in then brake fluid would also be able to get out so there would be a visible leak.

Also, assuming the threads are leaking when you go to bleed the system there is pressure outward so how would air get in anyway? Of course if you're using a vacuum bleeder than that would pose an issue but other than that I don't see how it could cause a problem assuming they seal fine when tight.
Old Oct 28, 2016, 10:46 AM
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Originally Posted by heel2toe
But my only point and/or question was assuming the threads are weaker from usage over the years or there was dirt and crap in there, as long as they are sealed once they are tightened back down what's the big deal?
Yea if they seal when they are tightened there is no issue. However, if a brake bleeder valve is bleeding slowly because of debris stuck in the valve and doesn't match the flow on other bleeder valves on calipers then air bubbles can get stuck behind that debris. Then it wouldn't matter how much you tried to bleed it. I verified this by pulling out the bleeder and there were air bubbles waiting behind it ready to come out.

Originally Posted by heel2toe
Also, assuming the threads are leaking when you go to bleed the system there is pressure outward so how would air get in anyway?

Air would not be able to get in when bleeding. It's just messy when that happens. Brake fluid comes out and spills all over the caliper.
I am talking more about thread tolerances. Why add thread sealant on a part that should seal when tightened down? It's because that tightening torque on that part is too high therefore poses a risk of breaking/stripping in order to seal or there is just enough gap for fluid/air to slowly seep out/in. Parts can fatigue and lose their manufactured tolerance over time. It's an aluminum caliper versus a brass valve(I think).
Old Oct 28, 2016, 11:30 AM
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Subscribing to this thread because I've been dealing with the exact same issue. No resolution as of yet.
Old Oct 28, 2016, 11:56 AM
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Originally Posted by deylag
Yea if they seal when they are tightened there is no issue. However, if a brake bleeder valve is bleeding slowly because of debris stuck in the valve and doesn't match the flow on other bleeder valves on calipers then air bubbles can get stuck behind that debris. Then it wouldn't matter how much you tried to bleed it. I verified this by pulling out the bleeder and there were air bubbles waiting behind it ready to come out.



I am talking more about thread tolerances. Why add thread sealant on a part that should seal when tightened down? It's because that tightening torque on that part is too high therefore poses a risk of breaking/stripping in order to seal or there is just enough gap for fluid/air to slowly seep out/in. Parts can fatigue and lose their manufactured tolerance over time. It's an aluminum caliper versus a brass valve(I think).
The thread aren't what seal the bleeder, it's the cone on the tip of the bleeder and the angled seat in the caliper that seal it.
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Old Oct 28, 2016, 05:05 PM
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Yea you are right. I remembered it wrong. Found this thread that helps to show that.

https://www.evolutionm.net/forums/ev...one-wrong.html
Old Oct 28, 2016, 05:47 PM
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Have you checked how free the pistons are in the caliper bores? I'm wondering if the seals got cooked. That would perhaps explain the smoking brakes on a cool day.
Old Oct 29, 2016, 09:43 PM
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seals shouldn't be - brand new high temp seals with racingbrake's vented pistons.

i replaced the brake lines today, but didn't get a chance to bleed the brakes. was very easy and straightforward. the rears were with calipers too - i installed onto the caliper first, then routed up to the hard line. i think in hindsight i may have reversed the process. it was easier getting the line onto the caliper than the line into the hard line after it had already been forced into an angle by being mounted onto the caliper. the driver's side rear really fought me, neither the hard line nor the ss line wanted to be in the bracket. managed to get everything on and tightened up though, just need to bleed & drive now. fingers crossed this fixes the problem
Old Oct 31, 2016, 06:41 AM
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new lines are in, bled the lines a few times but there's definitely still air in the system. the pedal definitely feels a little better though, but still a bit mushy for the initial 1" of travel.

im going to flush once more & pull the titanium shims out and see how the brakes feel without those on.
Old Oct 31, 2016, 07:06 AM
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my bet is u have air in the abs module.... i had a similar problem years ago.

countless brake line bleeds... i tried braking on gravel roads @ local nurseries, etc.. after getting kicked off of those gravely places to try & purge the abs mani.

i went back home & simply cracked each line loose @ the abs manifold while someone was apply brake pressure & I was amazed @ how much air came out of the abs manifold. especially after the gallon or 2 of brake fluid going thru the system....

dont knock it until you have bleed each line coming out the manifold, with someone apply brake pressure.

GL
Old Oct 31, 2016, 07:33 AM
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Originally Posted by Aby@MIL.SPEC
my bet is u have air in the abs module.... i had a similar problem years ago.

countless brake line bleeds... i tried braking on gravel roads @ local nurseries, etc.. after getting kicked off of those gravely places to try & purge the abs mani.

i went back home & simply cracked each line loose @ the abs manifold while someone was apply brake pressure & I was amazed @ how much air came out of the abs manifold. especially after the gallon or 2 of brake fluid going thru the system....

dont knock it until you have bleed each line coming out the manifold, with someone apply brake pressure.

GL
thanks - will try it, but curious about a few things - how did you see the air coming out of the abs module? was it bubbling up when you loosened the lines? did you use the same method (push pedal, open bleeder, close bleeder, release pedal, repeat)? Also, if you're cracking them open and watching air/fluid come out, that's got to be pretty darn messy - did you put something under it to catch the fluid?

if pushing the brake pedal actually forces brake fluid out of the ABS module, it's clear that air in the ABS module isn't just "in play" when the ABS is active (in other words, air in the ABS module WOULD impact brake feel).

Definitely interested in giving this a shot - heard you could only bleed ABS with a tool, which is why I was doing the "activate ABS" method after each bleed

Noob moment: we're just talking about loosening the lines on this guy and letting fluid leak out everywhere right:



Last edited by kyoo; Oct 31, 2016 at 07:49 AM.
Old Oct 31, 2016, 12:28 PM
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Originally Posted by kyoo
thanks - will try it, but curious about a few things - how did you see the air coming out of the abs module? was it bubbling up when you loosened the lines? did you use the same method (push pedal, open bleeder, close bleeder, release pedal, repeat)? Also, if you're cracking them open and watching air/fluid come out, that's got to be pretty darn messy - did you put something under it to catch the fluid?
do this first: I used a brake line wrench vs a regular open end wrench. i first made certain i broke loose each line without pressure, so i didnt strain myself or found i was in a goofy wrench position when going to crack each line loose.

yeah, i had a rag under it, but i cracked it loose to see fluid/air come out.

I wasnt trying to evacuate the abs module with new fluid thru those fittings up top.

just crack them enough to see fluid or "to see what you see" weep out between the inner part of the fitting to the line.

trust me, it was a WTF moment, when i witnessed bubbles coming out the 1st fitting i tried.



Originally Posted by kyoo
if pushing the brake pedal actually forces brake fluid out of the ABS module, it's clear that air in the ABS module isn't just "in play" when the ABS is active (in other words, air in the ABS module WOULD impact brake feel).
i guess so. all that i know, is that i was able to get air out of each line/fitting.

Originally Posted by kyoo
Definitely interested in giving this a shot - heard you could only bleed ABS with a tool, which is why I was doing the "activate ABS" method after each bleed
yeah, me to. i also read people would put the car on jack stands & get it going, pump brakes, i never tried that.

Originally Posted by kyoo
Noob moment: we're just talking about loosening the lines on this guy and letting fluid leak out everywhere right:


yes

fwiw, i dont recall if the car was idling or not, when i bled the abs mani.
Old Oct 31, 2016, 12:49 PM
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interesting. thanks for the updated details - and immediately after, stiffer brake pedal?
Old Oct 31, 2016, 05:28 PM
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Originally Posted by kyoo
interesting. thanks for the updated details - and immediately after, stiffer brake pedal?
yeah, normal brake pedal feel.
Old Nov 1, 2016, 04:40 AM
  #45  
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Someone posted a pic of an adjustment you can do on the brakes, I lost the pic but it's up under the hood behind the brake resouvare like some screw that pushes a plate, it was a page in the manual


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