Caliper Guide Pin Orientation

[NorCalA3]

Replaced my pads and rotors on my 8V A3 and assumed the caliper guide pins were the same when I pulled them out. When going to install, I realized they were different. One was normal and the other had a plastic band/bushing on it with a flat spot.

Does it matter which one goes on the top vs. bottom of the caliper? My brakes are squealing really bad. Could this be caused by installing them backwards?


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[rowlands57]

That would be in the lower position. Just checking, did you use appropriate brake lube on the guide pins and on the 'ears' and piston face on the calipers? If you don't then it's very likely you'll get squealing. Bedding in the pads is also helpful. Just search for that process on Google, there are a million good sources of information on how do bed them in. Some people just say drive gently for the first 500 miles and that will do the job as well.

[MikTip]

The plastic piece often comes off and is inside the caliper...

Before installing replacement ya have to dig it out.

Squealing pads are usually caused by the pads...

Not sure the exact reason why yours are squealing without physically seeing them...

Can you post pictures?

[NorCalA3]

That would be in the lower position. Just checking, did you use appropriate brake lube on the guide pins and on the 'ears' and piston face on the calipers? If you don't then it's very likely you'll get squealing. Bedding in the pads is also helpful. Just search for that process on Google, there are a million good sources of information on how do bed them in. Some people just say drive gently for the first 500 miles and that will do the job as well.

Confirming the pin with the plastic band goes in the lower position? I may have put mine at the top….

I used Permatex Silicone Extreme Brake Parts Lubricant for everything - guide pins, where pad clips meet caliper carrier, bass of pads where caliper ears and piston meet. Bedded in per manufacturers guidelines.

The brakes are actually extremely quit when applying them. The issue is the squeal like crazy when I’m coasting and not applying any pressure to the pedal. That why I was wondering if it could be the guide pin sticking.


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[NorCalA3]

The plastic piece often comes off and is inside the caliper...

Before installing replacement ya have to dig it out.

Squealing pads are usually caused by the pads...

Not sure the exact reason why yours are squealing without physically seeing them...

Can you post pictures?

Thanks. The plastic band didn’t get stuck in there. It’s still on the guide pin. Maybe I’ll post a pic if I’m able to get the car up in the air this weekend.


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[MikTip]

Its something with the pads...

What brand and type of pad did you buy? Ceramic?

Ceramics are known to make noise...

Also make sure the metal backing plate is in correctly and the wear indicator(if equipped) is not bent and touching the rotor with new pads

I have got brand new in the box pads and the metal tangs are all bent...

[NorCalA3]

Its something with the pads...

What brand and type of pad did you buy? Ceramic?

Ceramics are known to make noise...

Also make sure the metal backing plate is in correctly and the wear indicator(if equipped) is not bent and touching the rotor with new pads

I have got brand new in the box pads and the metal tangs are all bent...

EBC ceramic redstuff. I’ve have EBC in the past, but these are the new ceramic “formula”.

Yeah, metal isn’t touching the rotor from what I can tell. No metal wear tabs, these have the plastic coated wire sensor.


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[MikTip]

EBC ceramic redstuff. I’ve have EBC in the past, but these are the new ceramic “formula”.

Yeah, metal isn’t touching the rotor from what I can tell. No metal wear tabs, these have the plastic coated wire sensor.


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Im assuming old rotors?

If the rotors were not turned...the old pad material is on the rotors.

Did you "bed" in the EBC pads?

[NorCalA3]

Im assuming old rotors?

If the rotors were not turned...the old pad material is on the rotors.

Did you "bed" in the EBC pads?

Nope, brand new genuine Audi rotors. Bedded in per EBC instructions. ~500 casual around town miles, then “emergency” stops from 60mph-20mph. Got them nice and hot.


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[MikTip]

Nope, brand new genuine Audi rotors. Bedded in per EBC instructions. ~500 casual around town miles, then “emergency” stops from 60mph-20mph. Got them nice and hot.


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Pads...

[rowlands57]

One more thing to check is that the pads move freely in their brackets. If any of the clips/retainers are bound up the pad could be slightly jammed. They need to 'float' in their bracket and if they squeal when not applying brakes it makes me wonder if they are remaining in too close of contact with the rotors.

[NorCalA3]

One more thing to check is that the pads move freely in their brackets. If any of the clips/retainers are bound up the pad could be slightly jammed. They need to 'float' in their bracket and if they squeal when not applying brakes it makes me wonder if they are remaining in too close of contact with the rotors.

IMG_1980.jpg
They have these metal clips that were pretty tight to get in. I assumed they were suppose to be a snug fit to prevent them from rattling. Are they supposed to be compressed a little to allow for pad to move around?


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[rowlands57]

IMG_1980.jpg
They have these metal clips that were pretty tight to get in. I assumed they were suppose to be a snug fit to prevent them from rattling. Are they supposed to be compressed a little to allow for pad to move around?


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If they were hard to get into the brackets that's a problem. Those are more of a guide clip than a retention clip and the pads should move relatively easy in the brackets. Did you clean the tracks in the brackets where the pads fit in, in my area we get rust and rust jacking can be a problem over time.

[NorCalA3]

If they were hard to get into the brackets that's a problem. Those are more of a guide clip than a retention clip and the pads should move relatively easy in the brackets. Did you clean the tracks in the brackets where the pads fit in, in my area we get rust and rust jacking can be a problem over time.

The tracks only had some brake dust buildup, cleaned it up with a wire brush, cleaned with brake cleaner, then greased them. No rust. Maybe I’ll take them off and try compressing the clips a little. I just don’t want them to be so loose they rattle.


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[texasboy21]

I may have missed it, but when do the brakes squeal? All the time no matter what? Only during braking? During ALL braking for just when hot/cold?

If you have any doubts on the caliper pins, pad springs, etc. my suggestion is to take the 60 minutes to basically re-do the job and double check your work.

Brake are easily one of the top 3 things on a car that keep you alive - it's important to get it done right and with confidence.

[NorCalA3]

I may have missed it, but when do the brakes squeal? All the time no matter what? Only during braking? During ALL braking for just when hot/cold?

If you have any doubts on the caliper pins, pad springs, etc. my suggestion is to take the 60 minutes to basically re-do the job and double check your work.

Brake are easily one of the top 3 things on a car that keep you alive - it's important to get it done right and with confidence.

They squeal after they heat up a bit and only when I’m not applying any pressure to the brake pedal at low speed. Goes away after I go above 25 mph or so.

I’ve already pulled them off, double checked everything, re-greased contact points and backs of pads.

The brakes are great and stop on a dime, but the squealing is so embarrassing.

I’ve reached out to EBC and waiting to hear back on what they think the issue is. Might have to back to OEM pads.


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[rowlands57]

Yup that's about the only option given you have tried everything else. For what it's worth I had a set of defective pads on the rear of a Mazda that were eating the rotors due to a bad batch of friction material. It can happen and I was glad I caught that one before it became a bigger issue, they were constantly grinding. The noise was similar to the noise you get for the first use after the car sits for a while and the surface rust is being scrubbed off.

It is very frustrating to have to do the same job multiple times due to defective parts.

[texasboy21]

They squeal after they heat up a bit and only when I’m not applying any pressure to the brake pedal at low speed. Goes away after I go above 25 mph or so.

I’ve already pulled them off, double checked everything, re-greased contact points and backs of pads.

The brakes are great and stop on a dime, but the squealing is so embarrassing.

I’ve reached out to EBC and waiting to hear back on what they think the issue is. Might have to back to OEM pads.


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Not a bad plan. FWIW EBC are not anything special. The reds and yellows are both street pads, and you can get the same performance or better from countless other options.

I personally like StopTech Sport pads. They can handle daily driving (noise free), autox, track days, etc. without any fuss. The only downside is dust, they are not a low dust/ceramic wheel. They will be black/deep purple unless you clean them frequently.

[NorCalA3]

UPDATE:

Ok so EBC sent me a new set of pads. I have a little over 1k miles on them but they haven’t started squealing yet. Maybe it was just the pads, but I think it was the grease I used on the slide pins.

I originally used Permatex Cilicone Ceramic Extreme on all brake parts including slide pins. I think this was causing the rubber boots and bushing to expand and lock up the pins, resulting in the pads constantly rubbing on the rotors.

When I replaced the pads, I cleaned off the slide pins and insides of rubber boots and bushings. Greased with Syl-Glyde and used the non-silicone Permatex Ceramic Extreme (purple stuff) on metal contact points, backs of pads, and caliper ears.

Haven’t had any signs of squealing at all. Again, not sure if it was just a bad batch of pads I got, but have a feeling it was the grease.


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[MikTip]

UPDATE:
Ok so EBC sent me a new set of pads. I have a little over 1k miles on them and they aren’t squealing anymore. Maybe it was just the pads, but I think it was the grease I used on the slide pins.
I originally used Permatex Cilicone Ceramic Extreme on all brake parts including slide pins. I think this was causing the rubber boots and bushing to expand and lock up the pins, resulting in the pads constantly rubbing on the rotors.
When I replaced the pads, I cleaned off the slide pins and insides of rubber boots and bushings. Greased with Syl-Glyde and used the non-silicone Permatex Ceramic Extreme (purple stuff) on metal contact points, backs of pads, and caliper ears.
Haven’t had any signs of squealing at all. Again, not sure if it was just a bad batch of pads I got, but have a feeling it was the grease.

Nice!

[MikTip]

For many years I have used Mobil Synthetic grease...red. It works well for many applications!