Pedal feed back

[ZERO_5]

When on the brakes and making a turn I get a feed back from the brake pedal depending on how much I turn. Almost like the brake pedal gives out a bit. What could this be from? A problem with the power steering? I’m doing some work on the car this week end including brakes so I thought I should get this sorted out along with everything else. Also on a side note what brake fluid are you guys running? I would like to eventually start doing some rally cross, and figure if I'm flushing out the system I could put something like Motul DOT 4 oil. Is it worth it?

BTW car is a 93 Impreza L (1.8L) FWD auto, with about 270,XXX km

[RS-ti_Andy]

sounds electrical...

or warped discs..

hmm interesting

[wolfman79]

Check your brake lines, the crappy rubber ones. My 97 OBS did the same thing all the time. Threw some braided SS lines on and viola no more problem.

Motul 600 for me as for brake fluid.

[ZERO_5]

Don't think its warped rotors because its not really a pulsation type of feed back, and good idea on the braided lines! Thanks for the feed back guys.

[lorenkb]

Check out this thread (http://www.dirtyimpreza.com/forums/showthread.php?t=6631)for a bit of brake fluid info. The short of it is stay away from DOT5 fluids. Alternating between ATE Super Blue and ATE TYP 200 Amber is a popular choice due to identical specs and different color (easy to tell when you have completely flushed the old fluid during a change)

sounds electrical...

or warped discs..

hmm interesting

There should be a moratorium on you providing technical advice :unamused:

[UP2MTNS]

I get a lot of feedback from my brakes as well.

unfortunately they're not very good at giving feedback. a lot of criticism, foul language, and just generally abusive.

so I just stomp on them harder until they finally stfu....its a love hate relationship.

Andy...stop looking up 'moratorium' and just don't give any more tech advice.

[UP2MTNS]

seriously though, exactly what is the feedback if its not a pulsing?

when I had my abs plugged in, it would always act funny when I was braking on turns....didn't know what the hell it was at first until I pulled the ABS fuse. That would be my guess, but did they even have ABS in '93? man, that car is old. ;) just teasing.

[ZERO_5]

Well its hard to explain because I've never felt this problem in any other car... so lets say I'm approaching an intersection making a right turn at a green light and I'm slowing down. If I still have my foot on the brake as I enter, the brake pedal will drop a little after a certain degree of the steering wheel being reached, sorry for not explaining my self properly the first time lol

[wolfman79]

What you're describing sounds exactly like what I dealt with. I think that new lines will take care of that "sinking" pedal that you are getting. I know that on my OBS it did almost the exact same thing.

[UP2MTNS]

Well its hard to explain because I've never felt this problem in any other car... so lets say I'm approaching an intersection making a right turn at a green light and I'm slowing down. If I still have my foot on the brake as I enter, the brake pedal will drop a little after a certain degree of the steering wheel being reached, sorry for not explaining my self properly the first time lol

check your wheel bearings....both sides.

jack your car up and try to wiggle your tires side to side, and up/down.

I just replaced my right wheel bearing (and ended up replacing the whole hub)....it was so loose, on corners, it would push the brake caliper/piston and loosen it up. then I had to re-pump up the brake.

[ZERO_5]

sinking pretty much sums it up. I'll be looking in to a set of goodridge G-stop lines now. Any other recommendations ?

[RS-ti_Andy]

Check out this thread (http://www.dirtyimpreza.com/forums/showthread.php?t=6631)for a bit of brake fluid info. The short of it is stay away from DOT5 fluids. Alternating between ATE Super Blue and ATE TYP 200 Amber is a popular choice due to identical specs and different color (easy to tell when you have completely flushed the old fluid during a change)



There should be a moratorium on you providing technical advice :unamused:
sorry its just the last time i was driving a car... yesterday with brake feedback.. there are warped rotors..

[RS-ti_Andy]

Well its hard to explain because I've never felt this problem in any other car... so lets say I'm approaching an intersection making a right turn at a green light and I'm slowing down. If I still have my foot on the brake as I enter, the brake pedal will drop a little after a certain degree of the steering wheel being reached, sorry for not explaining my self properly the first time lol


ohh see if this is what he said originally.. i wouldnt have answered..

[scootfd3s]

Well its hard to explain because I've never felt this problem in any other car... so lets say I'm approaching an intersection making a right turn at a green light and I'm slowing down. If I still have my foot on the brake as I enter, the brake pedal will drop a little after a certain degree of the steering wheel being reached, sorry for not explaining my self properly the first time lol

Thats freakin strange. good luck with it man. i hope to know what really is the problem also.

[me_jimmy]

Well its hard to explain because I've never felt this problem in any other car... so lets say I'm approaching an intersection making a right turn at a green light and I'm slowing down. If I still have my foot on the brake as I enter, the brake pedal will drop a little after a certain degree of the steering wheel being reached, sorry for not explaining my self properly the first time lol
i think my car does the same thing feels like the brake pedal falls with rpm vacuum maybe?

[wolfman79]

check your wheel bearings....both sides.

jack your car up and try to wiggle your tires side to side, and up/down.

I just replaced my right wheel bearing (and ended up replacing the whole hub)....it was so loose, on corners, it would push the brake caliper/piston and loosen it up. then I had to re-pump up the brake.

That is a good idea as well especially with the mileage on the car. Even if it doesn't help the problem it still lets you know if the bearings are needing to be replaced any time soon.

i think my car does the same thing feels like the brake pedal falls with rpm vacuum maybe?

Wouldn't be a bad idea to check your vacuum lines to the booster either although I know that it wasn't the case on mine. If the symptoms are the same as mine were then they aren't really RPM dependent.

[ZERO_5]

Update:

Yesterday did new front pads and rotors and cleaned the rears (drums) and haven't felt it since. Hopefully it won't come back!

[UP2MTNS]

Update:

Yesterday did new front pads and rotors and cleaned the rears (drums) and haven't felt it since. Hopefully it won't come back!

nice....thanks for the update, I was interested to see.

glad it was a cheaper option than wheel bearings!

[RS-ti_Andy]

Update:

Yesterday did new front pads and rotors and cleaned the rears (drums) and haven't felt it since. Hopefully it won't come back!


I LOVE BEING RIGHT!! even when everyone flamed the crap out of me in the begining!

apoulagies demanded or well i guess this IS Nasioc after all..

[UP2MTNS]

I LOVE BEING RIGHT!! even when everyone flamed the crap out of me in the begining!

apoulagies demanded or well i guess this IS Nasioc after all..

sounds electrical...

or warped discs..

hmm interesting


i'm sorry, how were you 'right'? seriously, you went from random 'electrical' to 'warped discs'.....he changed pads and rotors, which means he also bled his brake lines and added more fluid. so it could have been 2 other things causing his pedal to drop(per his description of the 'feedback'), and it certainly wasn't electrical.


either way Andy, right or wrong, you can take your PM to me and shove it.

[wolfman79]

I LOVE BEING RIGHT!! even when everyone flamed the crap out of me in the begining!

apoulagies demanded or well i guess this IS Nasioc after all..

Just going to keep my mouth shut.

And ZERO_5 glad it was a simple fix for ya.

[RS-ti_Andy]

Just going to keep my mouth shut.

And ZERO_5 glad it was a simple fix for ya.


good.. keep it that way

[ZERO_5]

nice....thanks for the update, I was interested to see.

glad it was a cheaper option than wheel bearings!

Nope, wheel bearings f***ed too...getting that fixed sometime this week but I don''t think that was it because like I had mentioned, the "sinking" pedal is now gone....gotta love old cars

[lorenkb]

I LOVE BEING RIGHT!! even when everyone flamed the crap out of me in the begining!

apoulagies demanded or well i guess this IS Nasioc after all..

Just going to keep my mouth shut.

good.. keep it that way


Must have been those crazy electrical problems after all! Couldn't have been those new pads, cleaned drums, or bled lines! I think it's quite obvious that this isn't Nasioc; you are, after all, still free to post your drivel all over this board.

Apology denied.

[RS-ti_Andy]

i was talking about the rotors.. u all thought i was nuts .. oh well .. i realized that i dont know u.. and thats why i shouldnt give a crap.. just what ever

[wolfman79]

Nope, wheel bearings f***ed too...

Well that sucks man, at least you caught them before they gave out though.

I LOVE BEING RIGHT!! even when everyone flamed the crap out of me in the begining!

apoulagies demanded or well i guess this IS Nasioc after all..

The problem Andy isn't so much what you're trying to say but rather the way you go about saying it.

[RS-ti_Andy]

Well that sucks man, at least you caught them before they gave out though.



The problem Andy isn't so much what you're trying to say but rather the way you go about saying it.


okay sorry for any retarded'ness i have caused. thanks for being mature about the answer:bored:

[rollo]

Warped rotors wouldn't cause a "sinking" feeling in the brakes. Andy think about it, the rotors are spinning under the pads. When they're warped, on braking they "push back" on the pads each time the warped part comes around. One of the symptoms is brake feedback, you got that right. But the nature of the feedback is a juddering brake pedal (warped part of rotor pushes back on pad, pad pushes back on caliper piston, piston pushes back fluid, fluid pushes back brake pedal, brake pedal pushes back foot - repeat several times per second). But if it's the front rotors (and it usually is, since they do so much more of the work) the more noticeable effect is the steering wheel juddering as you brake, since the rotors on each side are uneven.

The higher the speed you're braking from, and the worse the warp, the more obvious the effect. If there's enough material left, you can get the rotors resurfaced (turned) or you can get new ones.

I'd say in this case it was more likely that the fluid was old and somewhat contaminated (water, air, whatever) and was compressing under harder brake pressure. Thus replacing the fluid was the fix, although the other stuff was good to do as well.

The fact that it was happening most obviously during corners is curious - except to Jon's excellent point, if the bearings are shot as well, the compound effect of bad bearings plus old fluid may be noticeable, whereas bad bearings only may not.