Spongy brakes after brake job - Need Help

[Mos2937]

I know I did a dumb thing so please dont judge need help before I start fixing the issue
I bought an Audi A6 recently and after finding it needs brakes changed I got the new drilled rotors and replaced all my rotors and pads little did I know about the EPB when I tried putting my rear calipers on it would not go in so the mechanicc guy that I know said that they have brake tools that rotate the piston in and press it to retract the piston but because I did not have any I used pliers to rotate and C-Clamp to push the pistons in and got the job done.
Now after that I had really s spongy brakes and I dont know what to do.

I understand that I fucked up my caliper but did I also fuck up my servo motor ? Do any of you know someone who did similar dumb thing to their car ?

[Burnt]

I did my front pads by myself and a brake fluid change with a vacuum attachment. Ever since the change by myself, my brakes have also been spongy. Did the change 30k miles ago and no change. I have start and stop, since they are more spongy, the brake goes in more and it actuates the stop function sooner.

[Audibot]

I did my front pads by myself and a brake fluid change with a vacuum attachment. Ever since the change by myself, my brakes have also been spongy. Did the change 30k miles ago and no change. I have start and stop, since they are more spongy, the brake goes in more and it actuates the stop function sooner.

Maybe that's why my Stop/Start kicks in before I've made a complete stop...

[Valpo A7]

I know I did a dumb thing so please dont judge need help before I start fixing the issue
I bought an Audi A6 recently and after finding it needs brakes changed I got the new drilled rotors and replaced all my rotors and pads little did I know about the EPB when I tried putting my rear calipers on it would not go in so the mechanicc guy that I know said that they have brake tools that rotate the piston in and press it to retract the piston but because I did not have any I used pliers to rotate and C-Clamp to push the pistons in and got the job done.
Now after that I had really s spongy brakes and I dont know what to do.

I understand that I fucked up my caliper but did I also fuck up my servo motor ? Do any of you know someone who did similar dumb thing to their car ?

Our cars have an electric emergency brake. If you forced them in with a c-clamp then chances are they are broke.

[sepheroth86]

https://www.ecstuning.com/Audi-C7_A6.../Caliper/Rear/

Not cheap to replace either!

[Valpo A7]

https://www.ecstuning.com/Audi-C7_A6.../Caliper/Rear/

Not cheap to replace either!

That is for the whole caliper and servo. You can get the servo by itself for $40 on ebay listed as new. Until it gets torn down to inspect what is what, its all speculation at this point.

[Valpo A7]

Simply retracting the caliper piston will not cause a spongy brake, something else is going on here. Chances are that the OP damaged the piston with the pliers but without seeing it its hard to say if he damaged it to the point of compromising the piston seal. If the seal is compromised then it should allow brake fluid leakage around the piston seal. If that is what is going on then the caliper needs replaced or rebuilt.

Its possible that simply bleeding the brake will get rid of the sponge feeling. I have done plenty of brakes in my lifetime and I can say I have not needed a brake bleed except 1 or 3 times and that was only because I had to disconnect lines for caliper or wheel cylinder replacement. Simply changing pads/rotors should not need to make you bleed brakes.

[JWebb_C7_Comp]

Simply retracting the caliper piston will not cause a spongy brake, something else is going on here. Chances are that the OP damaged the piston with the pliers but without seeing it its hard to say if he damaged it to the point of compromising the piston seal. If the seal is compromised then it should allow brake fluid leakage around the piston seal. If that is what is going on then the caliper needs replaced or rebuilt.

Its possible that simply bleeding the brake will get rid of the sponge feeling. I have done plenty of brakes in my lifetime and I can say I have not needed a brake bleed except 1 or 3 times and that was only because I had to disconnect lines for caliper or wheel cylinder replacement. Simply changing pads/rotors should not need to make you bleed brakes.

Would it make sense to get something like Carista or OBD11, activate the rear e bake, remove pads and look for sign that seal on one of the real caliper pistons is actually leaking... to me, that’s low cost and ma identify the issue. New or rebuild caliper might be next.... yikes!


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[OC Pablo]

OBD11 will be a great tool for this. Yes, you should inspect!

[Valpo A7]

If you are going to turn your own wrenches on an Audi then you really should invest in VCDS, Carista, or OBD11.


For the rear brakes there is another option on the table in that you can simply unplug the servos and physically remove them from the car. THEN you can run them in with a c-clamp like normal. Just do not turn the car back on until you get the servos back on the caliper and hooked up.

If you get a tool like I listed at the beginning then you will still likely have to retract the caliper a bit once the servos are run out of the way in order to get the new pads on the new or old rotors. That is simply a push them back in process, no need to twist them in or at least I did not have to do that on my 12 A7.

[Mos2937]

Update - I bought an OBD-II scanner initiated the EPB mode (I can hear the motors whirring in the rear) to retract the pistons and then ended the lining change mode (again I can hear the motors whirring) but the spongy brakes still exist. I can brake fine but just not as efficiently or maybe its just because of that spongy feeling. I tried engaging the E-Brake and then pushing the car (while in neutral) it does not move so I am at a loss here to what happened. Ordered used calipers off of ebay with air shipping it says was pulled out of a 2014 A6 with 60K miles (not believing but they look new). I will be replacing them this weekend will let you guys know what turned out to be the issue

[Vinng86]

Update - I bought an OBD-II scanner initiated the EPB mode (I can hear the motors whirring in the rear) to retract the pistons and then ended the lining change mode (again I can hear the motors whirring) but the spongy brakes still exist. I can brake fine but just not as efficiently or maybe its just because of that spongy feeling. I tried engaging the E-Brake and then pushing the car (while in neutral) it does not move so I am at a loss here to what happened. Ordered used calipers off of ebay with air shipping it says was pulled out of a 2014 A6 with 60K miles (not believing but they look new). I will be replacing them this weekend will let you guys know what turned out to be the issue

Have you tried bleeding your brakes? Checked for leakage of the brake lines? Spongy brakes can happen if there is air in your brake fluid since air is compressible.

Also, when you compressed your pistons did you open the cap for the brake fluid? Last time I did mine, I had to remove a few ounces of brake fluid.

[Valpo A7]

As Vinng86 says, BLEED THE OLD ONES FIRST. I would recommend a 4 corner bleed as well. If they are still spongy after that then replace.

[JWebb_C7_Comp]

Have you tried bleeding your brakes? Checked for leakage of the brake lines? Spongy brakes can happen if there is air in your brake fluid since air is compressible.

Also, when you compressed your pistons did you open the cap for the brake fluid? Last time I did mine, I had to remove a few ounces of brake fluid.

Is your fluid topped-up? As other wave said, bleeding COULD be the next cheapest solution.

Also, did you see any leakage around piston seals at current rear calipers or the lines..

Hate to see you install new calipers if they’re not the real problem, despite that everyone loves shinny new parts.




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[GilliamOS]

One tip I haven't seen in this thread when bleeding is rapping on the caliper near the bleeder valve with a dead-blow or hard rubber mallet to vibrate stuck air out of the piston chamber. It's surprisingly effective.

[vastano]

I also say you should bleed your brakes. I overextended my EPB on accident, realized what happened, fixed it and put everything back. I had a very spongy pedal. A couple weeks went by and the sponginess was still there. Did a 4 wheel brake bleed with a Motive bleeder and that rear caliper hade air in it, granted it wasnt very much. After this, my car brakes like OEM.