Please help - Rear Brake Pads - How to Retract the Caliper Piston

[ems657]

Hello folks,

I appreciate your helping hands. The rear caliper piston is also controlled by the electronic brakes, and it just wouldn't budge. The traditional caliper tool doesn't work...

If you have done this before, what tool did you use? Could you please post a link to purchase that tool?

Prior to doing the brake job, I watched a few youtubes and noticed this complication. By the way, if any one is doing the brake job, it requires a 7mm hex bit to loose the 2 outer screws.

Thank you,
Michael

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[EnjoyDriving]

i haven't done it yet, but hopefully this link would help. good luck and plz share your experience.

https://www.civicx.com/threads/emergency-parking-brake-post-brake-swap.34576/

 

[JSmoothBui]

At 17:00 you’ll see the thing to relax the brake. Also you’ll have to turn off the ebrake. If you haven’t removed the two things with the 7mm then do that first and remove the metal spring rod thing. Then remove brake pads then do thing I said earlier at 17:00 in the video to put the top of the rear brake pad on.

To relax the top of the rear brakes once removed you see in the video he used some odd tool. I was able to do it by carefully putting pliers between the notches and rotating them clockwise until Fully relaxed

Hope this made sense

 

[ctrmofo]

At 17:00 you’ll see the thing to relax the brake. Also you’ll have to turn off the ebrake. If you haven’t removed the two things with the 7mm then do that first and remove the metal spring rod thing. Then remove brake pads then do thing I said earlier at 17:00 in the video to put the top of the rear brake pad on.

To relax the top of the rear brakes once removed you see in the video he used some odd tool. I was able to do it by carefully putting pliers between the notches and rotating them clockwise until Fully relaxed

Hope this made sense

there are so many things wrong with flyinggato's video for brake replacement. careful.

 

[ctrmofo]

there are 2 ways:

1) dealer has software on laptop to retract the e-brake/vsa actuator before removing caliper for rear pads - without removing the actuator. obviously you don't have that software and is expensive, so to next option.

2) remove the actuator without the software: first you're supposed to have car on 4 jacks and disengage e-brake before turning off car. then remove the actuator (black unit attached to back of rear caliper). once removed turn the spindle to "lock" position ala clockwise. that will keep the piston from coming out.

assuming you've already taken the caliper off or rotated up, correct? if so, is the actuator still attached?

2 scenarios:

1) if you did not disengage the e-brake before shutting off car, you'll need to remove the actuator before you can turn the piston with the tool.

2) if you did disengage the e-brake before shutting off car, then use the tool to turn the piston.

this is the tool you need or can rent at local autozone or pepboys etc.: https://www.amazon.com/8MILELAKE-Br...er/dp/B0122Q83T4/ref=sr_1_3?crid=KJZETUPRMEQG

 

[dellyjoughnut]

this is the tool you need or can rent at local autozone or pepboys etc.: https://www.amazon.com/8MILELAKE-Br...er/dp/B0122Q83T4/ref=sr_1_3?crid=KJZETUPRMEQG

And if you got no tool, a crescent wrench large enough to fit into those two keyways will work. Would not recommend my procedure.

 

[ipeefreely]

Use this:

https://www.amazon.com/gp/product/B071F1KPPX/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

[Harlaquin]

So after treading this thread and seeing some other videos .. front pads a snap do your self at home. back pads take to dealer save yourself headaches. I mean for the everyday guy who only changes pads once every 3 or 4 years. Now you track guys yeah might wanna get all the tools for doing it yourself or would be a fortune to take to dealer every couple months

 

[EnjoyDriving]

Thanks and i want to make sure i got this alright:

1) Disengage ebrake while shutting the car off
2) Lift car up on 4 jacks
3) Remove rear wheels
4) Remove the actuator (unplugging the black unit??)
5) Turn the spindle to lock (like turning it clockwise all the way down, right??)
6) replace pads as usual
7) enjoy some cold beer

Appreciate your feedback

there are 2 ways:

1) dealer has software on laptop to retract the e-brake/vsa actuator before removing caliper for rear pads - without removing the actuator. obviously you don't have that software and is expensive, so to next option.

2) remove the actuator without the software: first you're supposed to have car on 4 jacks and disengage e-brake before turning off car. then remove the actuator (black unit attached to back of rear caliper). once removed turn the spindle to "lock" position ala clockwise. that will keep the piston from coming out.

assuming you've already taken the caliper off or rotated up, correct? if so, is the actuator still attached?

2 scenarios:

1) if you did not disengage the e-brake before shutting off car, you'll need to remove the actuator before you can turn the piston with the tool.

2) if you did disengage the e-brake before shutting off car, then use the tool to turn the piston.

this is the tool you need or can rent at local autozone or pepboys etc.: https://www.amazon.com/8MILELAKE-Br...er/dp/B0122Q83T4/ref=sr_1_3?crid=KJZETUPRMEQG

 

[ctrmofo]

Thanks and i want to make sure i got this alright:

1) Disengage ebrake while shutting the car off
2) Lift car up on 4 jacks
3) Remove rear wheels
4) Remove the actuator (unplugging the black unit??)
5) Turn the spindle to lock (like turning it clockwise all the way down, right??)
6) replace pads as usual
7) enjoy some cold beer

Appreciate your feedback

yes, correct. many forget that the e-brake must NOT be engaged before shutting off engine. once the caliper is removed, you're screwed.

 

[ez12a]

lol i've been reading all of these threads to get a better idea as well.

So even with disengaging the ebrake before maintenance, you still have to retract using torx? Is it because the ebrake does not retract the spindle all the way?

There's the "ball screw mechanism" that pushes the piston forward, which has to be retracted in order to push the piston back in. My question is even after releasing the ebrake you still have to unbolt the actuator and manually spin the ball screw mechanism with torx?

 

[willskiGT]

lol i've been reading all of these threads to get a better idea as well.

So even with disengaging the ebrake before maintenance, you still have to retract using torx? Is it because the ebrake does not retract the spindle all the way?

There's the "ball screw mechanism" that pushes the piston forward, which has to be retracted in order to push the piston back in. My question is even after releasing the ebrake you still have to unbolt the actuator and manually spin the ball screw mechanism with torx?

Yes, the procedure is the same on Audis and VWs with electronic parking brakes I've worked on. When you disengage the parking brake, the ball screw mechanism inside the piston doesn't retract enough to get the new pads in, and if you try to force the piston down with a traditional piston compression tool, you will damage the ball screw mechanism AND the parking brake electric motor. Procedure is as follows:

1. Disengage the parking brake
2. Jack up the corner of the car you're working on (chock the wheels/put into gear as the brake isn't engaged)
3. Remove caliper and old pads
4. Disconnect electric motor from parking brake ball screw mechanism
5. Manually retract the ball screw mechanism with torx driver
6. Use tool (from Autozone or wherever) to retract parking brake piston (do not force it - if you get resistance, you need to retract the ball screw mechanism more)
7. Install new pads
8. Manually extend ball screw mechanism with torx driver until parking brake piston is snug
9. Reconnect electric motor to parking brake ball screw mechanism

9 times out of 10, this procedure will work. On some of the newer Audis, the ECU checks the position of the e-brake when engaging/disengaging, and you can get an error or the motor can burn itself out trying to extend the parking brake to its previous position. I don't believe the FK8 checks this, so shouldn't be an issue.

 

[ez12a]

Makes sense now, thanks!

 

[ctrmofo]

^^^ you got it...torx ala turn to lock position manually after the actuator is removed.

 

[ems657]

@willskiGT

Thanks so much for your helping hands. Can I please ask for a bit more details?

4. Disconnect electric motor from parking brake ball screw mechanism
>> Is this to disconnect the harness/wires at the back?

5. Manually retract the ball screw mechanism with torx driver
>> Sorry, need some help. Are we sticking the torx driver into some hole from the outside of the ball screw mechanism?

6. Use tool (from Autozone or wherever) to retract parking brake piston (do not force it - if you get resistance, you need to retract the ball screw mechanism more)
>> Can I use a tool like this (someone suggested) https://www.amazon.com/8MILELAKE-Br...er/dp/B0122Q83T4/ref=sr_1_3?crid=KJZETUPRMEQG
>> Do we turn "clockwise"?

8. Manually extend ball screw mechanism with torx driver until parking brake piston is snug
9. Reconnect electric motor to parking brake ball screw mechanism
>> These 2 steps are essentially reversing step 4 and 5?

Obviously, our lives as home mechanics are getting tougher every few years. I am so thankful to have this support group & forum.

And no, I am not taking this to the dealer. The rear brake pads are tiny and I am at <30% after 12K miles (including 7 track days). Dealers will want an arm and leg from me.

Thanks and cheers!

Michael

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