Improving gen4 2.5i brake feel

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Improving gen4 2.5i brake feel

Postby noodle_snacks » Tue Dec 06, 2016 8:25 am

I recently purchased a used 2008 2.5i Liberty with about 51000kms on the odometer. I'm generally happy with the car, except that the brakes don't feel that great. I'd describe them as a bit mushy and requiring more pedal force than I'd prefer to stop the car. Digging through the service logbook, I think the brake fluid is 2.5 years old. Is it likely that things will improve a lot with a brake fluid flush? Is it that difficult to do? I've bled bicycle disc brakes plenty of times. Basically the same principle following the procedure in the service manual I'm guessing.

Would it help to change brake pads to ones with a higher friction coefficient than the OEM pads? The rotors front and back have very mild glazing and scoring, and the front pads have a <1mm lip close to the edge and close to the centre of the rotors. The steering wheel will wobble ever-so-slightly if I brake with my hands just off the wheel at highway speeds. But I can't really feel it with my hands on the wheel. Do I need to replace/machine the rotors if I get new pads? Are there any recommendations for pads (and rotors) if needed? Pad/rotor wear won't be a big issue for me. I don't commute to work, so my kms per year are relatively low.

Thanks.
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Re: Improving gen4 2.5i brake feel

Postby tigger73 » Tue Dec 06, 2016 9:20 am

Yes the things you're looking at doing should make a difference. I probably wouldn't bother with machining off the lip on the rotors - just replace them if you're putting on new pads. With 50,000km on them you're likely only have 30% life left in them anyway. Unless you're doing everything yourself, you'll end up paying for the labour twice.

Here's my suggestion:

  • Brake Flush
  • Brake Cylinder Stopper (to eliminate movement/flex of your brake master cylinder)
  • Upgrade brake pads (plus new rotors)
  • Braided brake lines
  • Upgrade rotors/calipers to GT/3.6R spec with 316mm rotors

Depending on your budget you could look at some or all of the above. Though if you're going to upgrade calipers/rotors I'd just do the master cylinder brace and brake flush now and run the stock pads/rotors down until you can afford to put on some bigger brakes.

I have a gen6 2.5 and always thought the brakes were a little underdone. I've put on 316mm 3.6R rotors, Intima SS pads and some second-hand gen4 GT calipers - front only. Braking is much improved now.
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Re: Improving gen4 2.5i brake feel

Postby noodle_snacks » Sun Dec 18, 2016 6:20 pm

Thanks for the advice. As an update I did a brake fluid flush with a mate. Some air came out of the front right line and the rear left, and things have improved significantly, though things still aren't mega awesome. I'll probably wait until I have more pad wear, and then I'll do the disc/rotor thing.
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Re: Improving gen4 2.5i brake feel

Postby robo498 » Tue Jul 18, 2017 8:31 am

Speak to Matt from kido racing, he tuned my 2.5l and made the brakes way better, not to mention the car runs way better and better fuel economy :D
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Re: Improving gen4 2.5i brake feel

Postby tom_kauf » Tue Jul 18, 2017 10:58 am

Good to hear they are better now. Pads made a good amount of difference for me. I went with StopTech Street Performance Pads. The initial bite is much better. The overall effort required to stop isn't a big difference, but the confidence of having it bite at light pressure means I don't feel like I have to press down on the brakes as much.
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Re: Improving gen4 2.5i brake feel

Postby steveP » Wed Jul 19, 2017 10:08 am

I noticed a big difference with pedal feel on my other cars with upgrading to braided lines. This is on the list next my the Liberty.
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Re: Improving gen4 2.5i brake feel

Postby crazyricochet » Mon Jul 24, 2017 1:52 am

I know exactly what you mean, the stock brakes are pretty shit, even shitter on the 2.5i. The stock pads are horrible

I would encourage you to buy a second hand set of GT/H6 brake calipers as they will fit on your car, then get some decent aftermarket rotors and pads, fluid. Braided lines are nice too but they are not strictly necessary as all the other parts will make much more of a difference.

Helps ALOT with braking force and pedal feel.
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