Honda Civic MB6 Brake pedal 'feedback' issue. Help please!
Discussion
100% nothing to do with disc run out. As the OP stated in his original post they are new.
If it were disc run-out, you would feel it at the wheel not through the pedal.
For you to feel anything pulsing through the pedal the discs would have to be cyclically getting thicker & then thinner....... Never going to happen, if you think about it, is it? If the discs are suffering from excessive run-out the pads/callipers would be sliding on their mounts, which you would not feel through the pedal.
If it were disc run-out, you would feel it at the wheel not through the pedal.
For you to feel anything pulsing through the pedal the discs would have to be cyclically getting thicker & then thinner....... Never going to happen, if you think about it, is it? If the discs are suffering from excessive run-out the pads/callipers would be sliding on their mounts, which you would not feel through the pedal.
Edited by andyiley on Wednesday 19th November 08:10
Burbleboy said:
It just seemed as though you were only interested in pulling me up for my post and not really helping. When changing fluid/bleeding brakes it is common sense to make sure there is no air in the system. I would have mentioned that in my post had there been any chance of air in the system but i didn't.
I used to like browsing the Gassing Station but PH has become shockingly bad for pedantic (seems to be the favourite word on here) and unhelpful members who deem it ok to abuse and make fun of every mistake others makes. I'm just ranting as you did nothing wrong. Just seemed as if you were having a pop and then left the thread hanging as you took days to reply when others kept the help going within minutes.
Sorry if this seems harsh, just how i viewed it. Cheers
Don't worry about it, as I said I am a pedantic git, I just wanted to get the symptoms right from you in case there was anything else I could think of to help.I used to like browsing the Gassing Station but PH has become shockingly bad for pedantic (seems to be the favourite word on here) and unhelpful members who deem it ok to abuse and make fun of every mistake others makes. I'm just ranting as you did nothing wrong. Just seemed as if you were having a pop and then left the thread hanging as you took days to reply when others kept the help going within minutes.
Sorry if this seems harsh, just how i viewed it. Cheers
Unfortunately there wasn't.
andyiley said:
If it were disc run-out, you would feel it at the wheel not through the pedal.
My experience says different. Especially if it's slight, under light braking (as the OP reports), or if it it's at the back.andyiley said:
For you to feel anything pulsing through the pedal the discs would have to be cyclically getting thicker & then thinner....... Never going to happen, if you think about it, is it?
1) No, the discs wouldn't have to be getting thicker & then thinner. They could be warped, or mounted slightly skewed to the hub, so that (as I explained above) they are acting as a kind of 'swash plate' relative to the caliper. This is the reason you need to ensure that hub faces are scrupulously clean when you're mounting a new disc. 2) Yes, discs sometimes do get thicker and then thinner. This can be due to machining inconsistencies, material inconsistencies, or irregular weathering/corrosion. The latter two are unlikely if the discs are newly replaced, The first is very likely indeed, to a degree that would cause feedback in conjunction with a seized caliper slide pin. It doesn't take much, and the machining on many new discs is far from perfect. The surface on any disc is never absolutely perfect.
By contrast, there is no mechanism by which air in the system will cause cyclical 'pulsing' at the pedal. On the contrary - it would absorb it, because air is compressible.
Sorry, but I'm going to be as blunt and rude as you are: I don't think you know what you're talking about, if you're suggesting that an improperly bled system could lead to pulsing feedback at the pedal under braking. In fact, I think you're talking b
ks.Sory once again I 100% refute ANY circumstances that a disc suffering with run out could cause any pulsing through the pedal.
The reason I asked whether the system had been fully bled was not bacause air can "cause pulsing in the system" but obviously because the OP mentioned the brake pedal "fighing back" when he was braking.
If you cast your mind back all that time ago when the OP originally posted that was when I suggested it, which is also when I asked him to be more descriptive. The reason I did this was because the description was a bit woolly & it could POSSIBLY have sounded like the compressible air was what was "pushing back" on the pedal.
Apart from that the OP did not mention light braking he mentioned "consistant braking", which probably means constant braking, no mention of how hard he is braking!
Must try harder!
The reason I asked whether the system had been fully bled was not bacause air can "cause pulsing in the system" but obviously because the OP mentioned the brake pedal "fighing back" when he was braking.
If you cast your mind back all that time ago when the OP originally posted that was when I suggested it, which is also when I asked him to be more descriptive. The reason I did this was because the description was a bit woolly & it could POSSIBLY have sounded like the compressible air was what was "pushing back" on the pedal.
Apart from that the OP did not mention light braking he mentioned "consistant braking", which probably means constant braking, no mention of how hard he is braking!
Must try harder!
andyiley said:
Sory once again I 100% refute ANY circumstances that a disc suffering with run out could cause any pulsing through the pedal.
Well, once again, I say you're talking bks (I've experienced it, diagnosed it, fixed it...), but perhaps you can suggest what you think would cause feedback through the pedal?andyiley said:
Not disc run out.
So you keep saying. 
But since I've had experience of it, you're gonna have to come up with a better explanation of:
a) Why it couldn't be run-out related and;
b) What it could be instead
... before you can convince me that you're not just a rude, arrogant asshole who doesn't know s
t, but likes to pretend that he does. 
Let's once again go back to the OPs original post shall we...... If you can manage that.
"After the 1 second of pedal feedback, the brakes are normal."
Does that sound like the saymptoms of disc run out to you?
You are REALLY trying to tell me the disc "runs out" for 1 second & then returns to normal?
"After the 1 second of pedal feedback, the brakes are normal."
Does that sound like the saymptoms of disc run out to you?
You are REALLY trying to tell me the disc "runs out" for 1 second & then returns to normal?
That is true, the pedal only pulses for around a second but is not continual.
It is hard to describe such things in words!
The flange facing was rust/dirt free when i fitted the discs, i can only think a pothole or something has maybe bent the hub facing somehow. My suspension is quite hard (coilovers) and that could be a contributary cause to any pothole/thump on road.
I would rather no name calling and fallouts here as i appreciate everyones input in this and taking the time to help me.
I WILL post up my findings once i check the sliders again and get a guage on the hub.
It is hard to describe such things in words!
The flange facing was rust/dirt free when i fitted the discs, i can only think a pothole or something has maybe bent the hub facing somehow. My suspension is quite hard (coilovers) and that could be a contributary cause to any pothole/thump on road.
I would rather no name calling and fallouts here as i appreciate everyones input in this and taking the time to help me.
I WILL post up my findings once i check the sliders again and get a guage on the hub.
andyiley said:
"After the 1 second of pedal feedback, the brakes are normal."
Read again what I wrote. I'm not saying that the primary problem is run out. I'm saying that the primary problem is a sticking caliper, but that it manifests itself because of the small amount of run-out that exists with any disc.If it's down to a sticky slider on the caliper, what's happening is that once you've pressed the brake pedal hard enough, for long enough (after that first second of initial pressure), it frees off and comes into consistent contact with the disc. The feedback is not the actual run-out that you're feeling... it's the pad 'grabbing' the disc cyclically as the high points rotate past.
The only other explanation is that the ABS is kicking in, but from the OP's description, I'm assuming that he can tell the difference between ABS actuating and another problem... and in any event, ABS doesn't actuate 'ever so slightly'.
Now, lets here your explanation for what you think is wrong, smart ass?
It's not the ABS kicking in as the car does not pitch nose down, tyres scrub etc. All the kickback is through the pedal and does not affect the braking like ABS kicking in normally would.
I think i will also try to disconnect the ABS and see if the kickback is still there, that way it ticks the preverbial ABS box!
I think i will also try to disconnect the ABS and see if the kickback is still there, that way it ticks the preverbial ABS box!
Edited by Burbleboy on Wednesday 19th November 20:51
The other simple test you might want to try is to take the car for a run for a few miles, using the brakes as lightly as you can.
When you get back, go around carefully poking your finger through the wheel to briefly touch the disc with the tip of your finger. If you weld the tip of your finger to one (if you're not quick enough!) because it's a lot hotter than the others, you've probably found your problem.
Don't necessarily rule out binding calipers if they're equally hot, front and rear, though, because it might be that they are equally sticky.
When you get back, go around carefully poking your finger through the wheel to briefly touch the disc with the tip of your finger. If you weld the tip of your finger to one (if you're not quick enough!) because it's a lot hotter than the others, you've probably found your problem.
Don't necessarily rule out binding calipers if they're equally hot, front and rear, though, because it might be that they are equally sticky.
Burbleboy said:
....laser temperature guns
Nonononono! It takes all the fun out of it if there's no chance of losing your fingerprints!Burbleboy said:
What about the brake master cylinder? Could that cause such things?
No, I don't think so. The piston in the master cylinder can only react to you pushing it - there's no way it can push back on its own (unless it's being driven by fluid being pushed back from the calipers)I must admit, I haven't asked the most obvious question: does the frequency of the feedback (ie. the rate of the pulses) seem to correspond to some degree with the speed the wheels are rotating?
MintSprint said:
I must admit, I haven't asked the most obvious question: does the frequency of the feedback (ie. the rate of the pulses) seem to correspond to some degree with the speed the wheels are rotating?
It doesn't do it at low speed...say 40mph and under i think. Seems to be higher speeds.MintSprint said:
Burbleboy said:
It doesn't do it at low speed...say 40mph and under i think. Seems to be higher speeds.
But when it does do it, is the rate of the pulsing related to the speed the wheels are rotating, do you think (ie. does it pulse faster at 80mph than at 40mph?)Burbleboy said:
Just to add, it doesn't do it any faster or slower when it happens...same two or three pulses say.
Then I have to say that that doesn't sound like a sticking caliper. You'd expect the 'pulsing' to be related to how fast the disc is rotating. 
But check it out as I've suggested, anyway...
It's not anything as simple as the brake pedal catching on something? It might seem a strange thing to ask, but do you get the impression that it's something that's happening after the direct mechanical part of moving the pedal?
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