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Replacing brake pads - cotter pin stuck!

11K views 21 replies 12 participants last post by  SuperChargerE55 
#1 ·
Replacing my brake pads and I have one cotter pin which will not budge at all. I have been using a 1/8 punch and lightly using a hammer to punch them out - all of them came out fine, but the top on one side. I actually broke my punch trying to get this one out and had to run to autozone to get another.

So, any ideas as to how to get this thing out? As it is sitting jacked up in the garage tonight I put some liquid wrench on there, but won't find out if that did anything till tomorrow. I assume it is the larger end with the compression ring (the inside end towards the engine) that is stuck.

Other things I thought of were applying some heat, but I am worried about how close that is to things. Another was drilling it as I am replacing with new ones anyways, but again a little worried with that as I want the new one to fit securely.

Surely someone else has run into this problem... what did you do to get it out?
 
#3 ·
Don't see what this has to do with the stuck pin - caliper could be good/bad/whatever... doesn't have anything to do with pushing the pins out.

Still thinking this one through, but haven't come across any good solutions yet. Here is hoping the liquid wrench does something over night, but if not I am open to all suggestions.
 
#8 ·
My belief is someone used other than the Mercedes pin. I had that happen on my 55 and after letting it stand in oil (which by the way did nothing) I took a pair of vice grips and attached them to the inside of the pin and used a hammer on the vice grips until the pin shifted. I then removed the vice grips and finished the removal with a punch. Apparently the tension clip on the end of the pin rusted. Now I grease the tension clips until I can get to the dealership for the pins with the stainless tension clip. Good luck.
 
#10 · (Edited)
I had this happen on my cayenne.

I cut the pin in half with a cutoff wheel on an angle grinder. That halved the friction and allowed me to punch each half out separately. Obviously this requires you buy a new pin set, but I doubt they are that expensive as the porsche set is like $20.

I dont know if you can get a 4.5" wheel on the pins without damaging the caliper, so you might need a dremel.
 
#13 ·
Well the liquid wrench did nothing and I also bought some stuff from AutoZone which they said was the best they had. It doesn't seem to be doing anything either.

If things don't change tonight I am going to cut the pin and try using a c-clamp to push out the stuck end (assuming it is the larger end with the compression ring). Throw a socket on the end I am pushing out so it fits through.

If that doesn't work then I guess drilling is the only other option. Little worried about that as I would want to use a smaller bit, but then that doesn't mean I'll be able to punch out what is left.

Just trying to avoid buying a new caliper as I don't want to go through the extra work of fitting a new one on.

The new pads came with new pins and the tension bracket that goes in the middle so not concerned about the old pins at all.
 
#15 ·
Have you tried using the ball Payne hammer.
Working on boats for years I was confronted with stuck and corroded bolts constantly from salt water. Tapping around the bolts works a treat. You have good access to the outside of the pin. Don't hit it to the stage of were it starts to deform. Just lots of light taps.
 
#16 ·
UPDATE :

Ending up cutting the pin. Made a cut on the inside of each brake pad. Once done then I could remove the tension bracket and middle section of the pin, slide the outside part of the pin out, and remove the outside brake pad. This gave me some room to use a larger punch on the inside part of the pin that was stuck. Plus the diameter of the pin is much larger now compared to the pointed tip you would normally punch from the front. A few taps with the hand sledge and it came right out.

For something that should have taken about 45 mins or so that took a while haha. For the record if anyone has trouble punching the pins out just cut them and be done with it (assuming you are replacing the pins).

Pumped the brakes a few times afterwards, test drive, everything is good to go. Thanks for the help and suggestions.
 
#17 ·
I could really use your advice,
1) what did you use to cut with?
2) Where did you cut could you mark my picture I am so afraid making more damage so I fabricated a rubber seal that fits the pin so I cant damage the paint when hammering should have thought about that first, always easy to be smart after lol but no one mention the tools to remove the pins with in any of the brake replacement DIY's really the most important to have
* Brembo Caliper Pad Pin Punch think is to expensive for what it is 14$ hmm
Brembo Caliper Pad Pin Punch

* Vice Grip
* Hammer/RubberHammer
* Chisel & Dorn propper size.

Nice my picture cant sit in the right direction no matter what way I turn it sorry for that keeps ending up like this sorry
 

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#20 ·
As someone else mentioned the pins have a 'barrel' on one end that is a compression fit. That end should be on the inside of the car (when you install them they go in from inside and you push them outward towards you or where the tire would be). So first thing to try would be using a punch on the outside and a mallet/hammer and lightly tapping from the outside in on the pin to see if you can release it.

If not, I used an electric saw with a blade for metal to cut mine when my original post happened. It is pretty self explanatory where you need to cut if you sit back and look at the setup and what you want to accomplish. I believe I made a cut on the far inside and then in the middle (between the two pads) on each pin. Those sections fall out of course and then allowed me to remove the inside pad. You can then do what you need to do for getting the other section of the pin out and the other pad. Now both pads are out and you have some room to get the stuck piece of the pin out (end with the compression fit). I used the same punch method and they popped right out this time.

You may also want to spray it down (any of those loosening solutions you can buy) and let it sit to help it a bit before trying. Just be careful not to spray it all over the place.
 
#18 ·
The locating pin that goes through the disc pads and caliper do have a shjaped cotter pin the is like a fig R .As you push the pin though the R shaped cotter pin goes in the small hole on the end to retain it .Some loose the retaining R shaped cotter pin , and just pop in a normal cotter pin instead . As for getting them out, like post above , file of the cotter clip and knock it out
 
#19 ·
info

No cotter pins in your brake calipers Only a round pin with with a split barrel type thing on the one end .And as you push it in , itgoes through both caliper and pads .And it retains inside with pressure from the split barrel thats on the end. See pics single one is for the front the others are rears
 

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#22 ·
Excactly that super super thanks mate. Yes got the kit already attempted replacing it Saturday unfortunately my health is not what it had been sucks have to abort this time due to my chappy back disc something lol just pulling of 1 tyre and working in that position totally surprised me Sunday morning baaa. So spoke to AMG center they do it for me Thursday feels bad really but asked him and he also said it happens all the time they get stuck they heat them little bit and the break the pin my guess is cutting it will see Thursday will follow him closely.

Ordering the lot for next time and also just ordered the pin tool is good to have next time lol if a next time will be :) Thanks again appriciate it and am sure a lot will use this for reference thanks bro
 
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