Xoutpost.com - DIY Parking Brake Replacement

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Quote:

Originally Posted by 08-730d (Post 1087250)

Well well. Looks like things are looking up at the moment. Got it coded today and adjusted the brake shoe tensioner. And now it seems to be fine. It just made sweet sounds (altough i haven´t dared to operate it more than once..).

I did also study the first unit that broke. Nothing looks to be burned, and it ran fine while putting power directly to the motor.
I also used it to measure, and found that the only thing I could have done better with the new one was to adjust the bowden cable screw 3mm further out, than it is (or 1,75 turns of the screw). In total the screw has about 50-55 mm of travel, and 3 mm should not make that big of a difference.
I also studied the bowden cable connection inside the brake disc. It looks to me that the ratio of how much the cable moves vs how much the brake shoes are moved is not in our favour. By that I mean that it looks like the cable has to move a lot more than what we get in brake shoe motion. Therefore I would presume that it would be beneficial for the operation of the park brake system to keep this movement as low as possible, by adjusting the brake shoe tensioner so that the brake shoes almost rub.

I don´t know if that makes sense to you others, but it makes sense to me.

Fingers crossed that it keeps on working..

Great to hear, yeah I've been using mine every time I park and it's been great.

Yes typically with any drum brake setup you want the shoes to be causing the slightest drake on the drum to ensure they can have good response when being actuated. This holds true for regular drum brakes or emergency brakes. Once you get your inspection and you feel comfortable use it on a regular basis, it will likely prolong it's life.

On my old unit the motor was pulling around 2 amps, everything else looked fine, it was only one chip on the old control board that was burnt out. I could connect to it using tool32 and it was still able to be flashed and provide error codes etc but ultimately it was bad. Nothing physically looked burnt but as far as I could tell one part of the board went bad.

So my advise for others attempting this is either get yours rebuilt or buy a remanufactured one, trying to repair your own is pretty pointless.

Hi Aveman,
Watched your video on YouTube and installed my new Parking brake Actuator today.
1 question though: Do I need to install the rotors and the brake calipers before I can test if it works? I tried coding it by doing an SG_CODERIEN but the error still comes up on the dash and I can't hear the motor in the module turning. I want to test the new module works before putting everything back together so I don't have to take everything apart again if it doesn't work or will I need to install everything back before I can test?
Cheers mate,
Stevie.

Hi Stevie,

Yes you would have to put it back together and actuate it once for your error to clear. The module has a force sensor so it needs to sense a certain amount of pressure. Running it while it's not connected to anything would just result in another error.

You could still atleast get it to try and cycle if you just want to confirm its not DOA. Try holding down the park brake button, that will reset it and you can listen for the motor. But like I said the actual error probably won't clear until it's all back together.

Many thanks for your prompt reply.
I did try holding down on the park brake button for around 30secs but nothing happened.
I'll put everything back tomorrow and see how it goes.
Will keep you posted.
Thanks once again.

Quote:

Originally Posted by x5stevie (Post 1088720)

Okay what error was on your dash after installing the new one?

Mine said "park brake, vehicle may roll" when I put the new module in vs "park brake malfunction". Once I pushed down on the park brake button it cleared. Good luck, if you have the same error with the new module maybe check to ensure the plug and harness are in good shape and not burnt up.

I have the parking brake fault, car may roll warning. Can't remember exactly what the message was before installing the new one, but i think it was park brake malfunction.The Actuator was very noisy the day it got stuck. Pulling the release cable in the boot didn't help, so I eventually had to cut the parking cable with a bolt cutter to drive home.

Quote:

Originally Posted by x5stevie (Post 1088727)

Okay sounds like you're in good shape then, the vehicle may roll warning is what you'd want to see. Once it's all back together and you actuate it the fault should clear.

You are a star mate. I Put everything back together, depressed the hand brake switch for around 15secs and I could hear the actuator working and warning light disappear.
Many thanks for your help with this, you just saved me £800 by not going to the dealer.
Now I need to go and get a case of beer and knock myself out.

Your vid was a life saver! One question though. When installing the replacement unit , complete with new cables, did you remove the cables from the new unit first? Or can you leave the cables attached to the actuator and still stuff it all into place? Thx

When I replaced mine, I re-used the old cables that my car came with. It was a lot of extra effort to get them attached in the confined area under the car. I would recommend you use the new cables.

Pulling the wheels and brakes is no fun either but at least you are not on your back trying not to break a plastic cable retainer.