Brake/Caliper question.....how can this happen.......
08-19-2011, 03:49 PM
#21
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These pics help. when you said the 'top' of the pad is more worn, it's really one 'side' (where you can see the rivet). This helps me believe it's a stuck piston vs. the caliper being spread.
The piston behind the rivited side is mose likely stuck, causing additional drag on that side of the pad, and causing it to wear quicker. As it wears, it eventually works it's way across the entire pad (as seen), but you can still tell one side is dragging mroe than the other.
either rebuild it, or replace (I vote replace).
The piston behind the rivited side is mose likely stuck, causing additional drag on that side of the pad, and causing it to wear quicker. As it wears, it eventually works it's way across the entire pad (as seen), but you can still tell one side is dragging mroe than the other.
either rebuild it, or replace (I vote replace).
08-19-2011, 03:52 PM
#22
These pics help. when you said the 'top' of the pad is more worn, it's really one 'side' (where you can see the rivet). This helps me believe it's a stuck piston vs. the caliper being spread.
The piston behind the rivited side is mose likely stuck, causing additional drag on that side of the pad, and causing it to wear quicker. As it wears, it eventually works it's way across the entire pad (as seen), but you can still tell one side is dragging mroe than the other.
either rebuild it, or replace (I vote replace).
The piston behind the rivited side is mose likely stuck, causing additional drag on that side of the pad, and causing it to wear quicker. As it wears, it eventually works it's way across the entire pad (as seen), but you can still tell one side is dragging mroe than the other.
either rebuild it, or replace (I vote replace).
Also, wouldn't a stuck piston cause my car to want to pull towards that side, since its still compressing the brakes a little bit.
.
08-19-2011, 04:13 PM
#23
Yeah they are tapered somewhat. One thing that confuses me slightly is you are saying it is the top half. If that is the passenger inboard, isn't that the bottom part of the pad, which would be the 'leading edge' against the rotor when the wheel is spinning forward?
Without actually being able to look at your car myself, my best guess is that the pins were seized. The point of the pins for the floating caliper is to transfer some force to the outboard pads. If the pins seize the pistons only push on the inboard pad so the inboard pad on that side does all the braking on that wheel.
I would have figured you would have noticed something odd when compressing the pistons the last time if a piston was seized. You have to compress the pistons to put new pads in. However, you don't have to do anything to the pins and a lot of people don't inspect them when they switch out pads. It just is something that hasn't been ingrained with a simple brake pad change.
There are some other odd things that can occur with pads. Some may start to disintegrate if they go over temperature, some are just not manufactured right and will disintegrate. The other thing is that since they are worn so low, it could have just started disintegrating off the backing plate.
The pins aren't too expensive and if they are original they could probably stand to be replaced since they aren't hugely expensive. At the least I figured checking them to make sure they weren't stuck and cleaning and re-greasing them is in order if they haven't been before. That's really just good PM every time you change the pads to make sure you don't get one that sticks.
Without actually being able to look at your car myself, my best guess is that the pins were seized. The point of the pins for the floating caliper is to transfer some force to the outboard pads. If the pins seize the pistons only push on the inboard pad so the inboard pad on that side does all the braking on that wheel.
I would have figured you would have noticed something odd when compressing the pistons the last time if a piston was seized. You have to compress the pistons to put new pads in. However, you don't have to do anything to the pins and a lot of people don't inspect them when they switch out pads. It just is something that hasn't been ingrained with a simple brake pad change.
There are some other odd things that can occur with pads. Some may start to disintegrate if they go over temperature, some are just not manufactured right and will disintegrate. The other thing is that since they are worn so low, it could have just started disintegrating off the backing plate.
The pins aren't too expensive and if they are original they could probably stand to be replaced since they aren't hugely expensive. At the least I figured checking them to make sure they weren't stuck and cleaning and re-greasing them is in order if they haven't been before. That's really just good PM every time you change the pads to make sure you don't get one that sticks.
08-19-2011, 04:35 PM
#24
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I'm having the same problem and the pistons are getting stuck after inspecting them more...how do you take the pistons off? or is it better to buy brand new caliper?
08-19-2011, 04:56 PM
#25
http://www.installuniversity.com/ins...er_rebuild.htm
That is how you do it... although that guide is if they aren't completely trashed.
I might just buy a rebuilt one.
That is how you do it... although that guide is if they aren't completely trashed.
I might just buy a rebuilt one.
08-19-2011, 05:15 PM
#27
****............
So I just came back from the auto parts store. On the way back every time I stopped completely...while I;'m sitting still......if I slightly lift my foot off the pedal to release some of the pedal pressure, but not all the pressure, so the car will barely inch forward, the passengers side brake makes a loud scrubbing noise.......then when I push harder it stops the car. Braking from a cruising speed makes no noise and the car comes to a stop without a sound at all.
So maybe one piston is pushing on that pad...........
Screw it, I'm getting a new caliper tomorrow. The pin and boot kits I bought today are needed anyway.
.
So I just came back from the auto parts store. On the way back every time I stopped completely...while I;'m sitting still......if I slightly lift my foot off the pedal to release some of the pedal pressure, but not all the pressure, so the car will barely inch forward, the passengers side brake makes a loud scrubbing noise.......then when I push harder it stops the car. Braking from a cruising speed makes no noise and the car comes to a stop without a sound at all.
So maybe one piston is pushing on that pad...........
Screw it, I'm getting a new caliper tomorrow. The pin and boot kits I bought today are needed anyway.
.
08-19-2011, 05:20 PM
#28
But all the analyzing is just reversed, same issue(s) we've all talked about apply, right?
Without actually being able to look at your car myself, my best guess is that the pins were seized. The point of the pins for the floating caliper is to transfer some force to the outboard pads. If the pins seize the pistons only push on the inboard pad so the inboard pad on that side does all the braking on that wheel.
I would have figured you would have noticed something odd when compressing the pistons the last time if a piston was seized. You have to compress the pistons to put new pads in. However, you don't have to do anything to the pins and a lot of people don't inspect them when they switch out pads. It just is something that hasn't been ingrained with a simple brake pad change.
There are some other odd things that can occur with pads. Some may start to disintegrate if they go over temperature, some are just not manufactured right and will disintegrate. The other thing is that since they are worn so low, it could have just started disintegrating off the backing plate.
The pins aren't too expensive and if they are original they could probably stand to be replaced since they aren't hugely expensive. At the least I figured checking them to make sure they weren't stuck and cleaning and re-greasing them is in order if they haven't been before. That's really just good PM every time you change the pads to make sure you don't get one that sticks.
I would have figured you would have noticed something odd when compressing the pistons the last time if a piston was seized. You have to compress the pistons to put new pads in. However, you don't have to do anything to the pins and a lot of people don't inspect them when they switch out pads. It just is something that hasn't been ingrained with a simple brake pad change.
There are some other odd things that can occur with pads. Some may start to disintegrate if they go over temperature, some are just not manufactured right and will disintegrate. The other thing is that since they are worn so low, it could have just started disintegrating off the backing plate.
The pins aren't too expensive and if they are original they could probably stand to be replaced since they aren't hugely expensive. At the least I figured checking them to make sure they weren't stuck and cleaning and re-greasing them is in order if they haven't been before. That's really just good PM every time you change the pads to make sure you don't get one that sticks.
Do I just use a flat head screwdriver and a hammer to tap it out...if it is stuck?
However.....if both pins come out easily.......is it the piston(s)......and I need a new caliper.
They're so cheap, I should just get two new calipers and call it a day.....
.
Last edited by LS6427; 08-19-2011 at 05:31 PM.
08-19-2011, 06:06 PM
#29
OK....you make total sense. Tomorrow when I take the caliper back off.....do I simply grab the pins with my fingers to see if they both come right out easily? Is it that simple. If one doesn't come out then its seized up in there, right?
Do I just use a flat head screwdriver and a hammer to tap it out...if it is stuck?
They're so cheap, I should just get two new calipers and call it a day.....
RE the noise, did you bed the new pads in well, although I wouldn't expect a loud noise? It's hard to really understand what noises sound over a forum. It doesn't pull to one side or the other? How many miles have you driven on the new pads? This is the first issue with the new pads?
As far as seized piston, I dunno. If they compressed easily I don't see how they could have seized. You can push them too far in if you just compress directly on the piston which may jam them into the caliper, but if you compressed against a pad I wouldn't have expected them to jam in there... that is unless the dust boots or seals failed and it got junk inside them.
08-19-2011, 06:09 PM
#30
They are something like $40 reman + core charge which isn't horrible. I guess most come with a warranty though. I wouldn't just throw $80 at the car without at least checking if they are seized first.
As far as the noise, did you bed the new pads in well? It's hard to really understand what noises sound over a forum.
As far as the noise, did you bed the new pads in well? It's hard to really understand what noises sound over a forum.
What do you mean, bed the pads in well?
.
08-19-2011, 06:13 PM
#31
For instance Hawk has the following instructions:
After installing new pads make 6 to 10 stops from approximately 35 mph with moderate pressure. Make an additional two to three hard stops from approximately 40 to 45 mph. Do not allow the vehicle to come to a complete stop.When completed with this process, park the vehicle and allow the brakes to cool completely before driving on them again. Do not engage the parking brake until after this cooling process is compete.
08-19-2011, 09:40 PM
#32
Just I mean bedded them to the rotor. If you don't get an even layer of pad onto the rotor they can make noise. Or if you switch pad compounds without cleaning the rotor then sometimes the new material doesn't deposit evenly and can lead to noise. It wouldn't imagine that would make a loud noise though.
For instance Hawk has the following instructions:
I might pull the wheel and put evenly worn pads in the caliper (if you still have them), then bolt it up and pump up the brakes, then take the caliper off and make sure the pistons moved out equally. Mainly just so you aren't shooting the pistons at the rotor face, or into emptiness.
For instance Hawk has the following instructions:
I might pull the wheel and put evenly worn pads in the caliper (if you still have them), then bolt it up and pump up the brakes, then take the caliper off and make sure the pistons moved out equally. Mainly just so you aren't shooting the pistons at the rotor face, or into emptiness.
Question is:
Do I get two new ones for the front? Or is there absolutely no reason if the other one if fine? It won't be uneven in any way, right?
How much grease do I put on the new pins?
When I slide the new pins in.....how far do I push them in? Just enough to get the caliper on?
And just to be sure.......when I tighten the caliper bolt, do I simply hold the pin with the open end wrench and tighten the bolt as much as it'll go, thats it?
My first time ever doing brakes...believe that ****.....
.
08-19-2011, 11:04 PM
#33
It sounds like its no the caliper. If anything, it would be the caliper bracket. (Where the pins go in.
Whenever I do something to one wheel, I always do the same to the other side of the car. You can treat the front and back as separate things - no problem, but having left and right perform the same is usually a good idea. (Unless you are racing in circles.)
A liberal amount. They should be well covered but not caked on. Kind of like a thick glazing on a doughnut.
yep
That's the method, but its best to torque them properly to spec.
It won't be your last.
A liberal amount. They should be well covered but not caked on. Kind of like a thick glazing on a doughnut.
It won't be your last.
08-20-2011, 09:21 AM
#35
The amount of grease is pretty liberal. It will leak out around the boot if you put too much. I don't think that is a big deal, if you slather it on and it leaks out, just wipe it off and re-seat the boot.
If you have new pads the pins will need to be all the way in the bracket. In fact, the boots will try to hold them all the way in when the caliper is attached. When you put the bolt through the caliper into the pin, it will pull the pin out as much as it needs. No thinking required.
The caliper pin bolts for the front are to be torqued to 23ftlbs... it isn't a huge number, but like I said if you are using a small 3/8in drive ratchet it will feel like a decent torque, not really gorilla torque.
The pin guides or channel in the pad abutment bracket can potentially wear out, corrode and become out of round. It isn't all that common, but can happen. If you grease the new pins and slide them in, just give them a wiggle. If there is hardly any play it should be fine.
If you have new pads the pins will need to be all the way in the bracket. In fact, the boots will try to hold them all the way in when the caliper is attached. When you put the bolt through the caliper into the pin, it will pull the pin out as much as it needs. No thinking required.
The caliper pin bolts for the front are to be torqued to 23ftlbs... it isn't a huge number, but like I said if you are using a small 3/8in drive ratchet it will feel like a decent torque, not really gorilla torque.
The pin guides or channel in the pad abutment bracket can potentially wear out, corrode and become out of round. It isn't all that common, but can happen. If you grease the new pins and slide them in, just give them a wiggle. If there is hardly any play it should be fine.
08-20-2011, 11:59 AM
#36
The amount of grease is pretty liberal. It will leak out around the boot if you put too much. I don't think that is a big deal, if you slather it on and it leaks out, just wipe it off and re-seat the boot.
If you have new pads the pins will need to be all the way in the bracket. In fact, the boots will try to hold them all the way in when the caliper is attached. When you put the bolt through the caliper into the pin, it will pull the pin out as much as it needs. No thinking required.
The caliper pin bolts for the front are to be torqued to 23ftlbs... it isn't a huge number, but like I said if you are using a small 3/8in drive ratchet it will feel like a decent torque, not really gorilla torque.
The pin guides or channel in the pad abutment bracket can potentially wear out, corrode and become out of round. It isn't all that common, but can happen. If you grease the new pins and slide them in, just give them a wiggle. If there is hardly any play it should be fine.
If you have new pads the pins will need to be all the way in the bracket. In fact, the boots will try to hold them all the way in when the caliper is attached. When you put the bolt through the caliper into the pin, it will pull the pin out as much as it needs. No thinking required.
The caliper pin bolts for the front are to be torqued to 23ftlbs... it isn't a huge number, but like I said if you are using a small 3/8in drive ratchet it will feel like a decent torque, not really gorilla torque.
The pin guides or channel in the pad abutment bracket can potentially wear out, corrode and become out of round. It isn't all that common, but can happen. If you grease the new pins and slide them in, just give them a wiggle. If there is hardly any play it should be fine.
.
08-20-2011, 05:40 PM
#37
So, I installed the new pins and boots. The new pins had no wiggle in the pin holes, like none. So I guess thats a good sign. When I pulled the old pins out they came out easily and had suction as I pulled them out.
The pistons on that problem side were both extended outward equally when I slid the caliper off.....so they're both moving outward evenly for sure.
I went for a drive and all sounds and operates perfectly. Not pulling to that side when I release the brake pedal and no sound coming from that side either.
I guess I'll just check them in about 2-3 months to see how that inboard pad is wearing.
.
The pistons on that problem side were both extended outward equally when I slid the caliper off.....so they're both moving outward evenly for sure.
I went for a drive and all sounds and operates perfectly. Not pulling to that side when I release the brake pedal and no sound coming from that side either.
I guess I'll just check them in about 2-3 months to see how that inboard pad is wearing.
.
08-21-2011, 12:17 AM
#39
Not to beat this thread to death.....
I just don't understand how an inboard pad can wear so much faster than its outboard pad. The pins were very free moving and the pistons were out evenly today when I took them off and they were both out evenly the other day when I took them off.
How about if one piston DOES NOT retract after pressure is applied......can that happen?
If yes.....wouldn't it pull to that side or at least make noise?
And what causes the pistons to retract after the pedal is released?
Sorry.....I'm just perplexed......
.
I just don't understand how an inboard pad can wear so much faster than its outboard pad. The pins were very free moving and the pistons were out evenly today when I took them off and they were both out evenly the other day when I took them off.
How about if one piston DOES NOT retract after pressure is applied......can that happen?
If yes.....wouldn't it pull to that side or at least make noise?
And what causes the pistons to retract after the pedal is released?
Sorry.....I'm just perplexed......
.
08-21-2011, 06:33 AM
#40
Its gotta be the pins. Even if the caliper was bad and dragging, the pins would balance the force between the inner and outer pads. If the inboard pad is wearing and the outboard is not, the pins must not be doing the job (braking force) or something with the pad or rotor surface is not consistent from the inside to the outside (reduction of friction).
Maybe something other than the grease was binding the caliper bracket and keeping it from moving?
Maybe something other than the grease was binding the caliper bracket and keeping it from moving?