Author Topic: Brake Pedal feel  (Read 1491 times)

Offline rowlers

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Brake Pedal feel
« on: 09 January 2025, 19:49 »
Strange one this, so just trying to find out if anyone else has had similar...

Brakes were great, no issues.

Done a routine (pressure 10psi) brake fluid change back in November. Pedal was fine for a couple of weeks then I started to notice it getting lower to the floor under gentle braking, then it will be fine for ages. Then it goes funny again.

When doing the bleed, I noticed the front discs and pads were near end of life, so I changed them and the pedal was fine again for a couple of weeks. Then started going funny again. So I re-bled, at 20PSI, a few air bubbles came out of each caliper.

Again pedal has been great for about a month, and just today I've noticed it getting a bit soggy feeling now and again.

I'm not sure where to go next, another bleed at the recommended 30PSI?
Calipers all appear to be freely sliding.
I've read it could be the master cylinder/servo? But also read that they very rarely fail/go wrong?

Any one any clues?

Offline EB2019

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Re: Brake Pedal feel
« Reply #1 on: 10 January 2025, 11:54 »
Sorry never really heard of this issue, does sound strange like you say.   

You're def not losing fluid?

Well we keep a clutch master cylinder in stock at all branches, so I guess it must be a common thing.

SCRAP THAT I looked up clutch master lol, nothing to see here.







 
« Last Edit: 10 January 2025, 14:42 by EB2019 »

Offline rowlers

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Re: Brake Pedal feel
« Reply #2 on: 10 January 2025, 14:46 »
Nope not using fluid, just passed its MOT so can assume all lines are good and must have passed the braking test.

Everything I've read points to air in the lines, so I'll give it another bleed, plus the "old fashioned" bleed, but I'll need another pair of hands for that.

Offline madstaff

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Re: Brake Pedal feel
« Reply #3 on: 10 January 2025, 16:48 »
I would try bleeding the old fashioned way with the aid of an assistant.

There is a recommended bleed sequence which is completely opposite to the way i would have done.

Think its NSF, OSF, NSR, OSR.

Could also use a little pressure combined with the old fashioned method.
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Offline Wayne.R

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Re: Brake Pedal feel
« Reply #4 on: 29 January 2025, 09:38 »
Have you used VCDS to bleed the ABS pump after the fluid change? There could well be air trapped in the system and this is what is causing you issues.

On my Audi I needed to do this after a fluid change, to ensure all was fine. I’m assuming being a VW there is no difference.

I wouldn’t bleed under 30psi. Way too much pressure.
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Offline rowlers

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Re: Brake Pedal feel
« Reply #5 on: 29 January 2025, 12:46 »
Have you used VCDS to bleed the ABS pump after the fluid change? There could well be air trapped in the system and this is what is causing you issues.

On my Audi I needed to do this after a fluid change, to ensure all was fine. I’m assuming being a VW there is no difference.

Not done an ABS bleed as only thought necessary for ABS pump, master cylinder change etc...

30psi is too much? Thats the recommended pressure in the dealer manual as far as I know.
I wouldn’t bleed under 30psi. Way too much pressure.

Offline Ian Mack

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Re: Brake Pedal feel
« Reply #6 on: 01 February 2025, 13:34 »
I had this exact same issue. New discs, pads and brake fluid change but brakes always felt a little spongey and occasionally worse. Changed the master cylinder which apparently on our golfs runs both the brakes and clutch(so i was told ?) and it feels like a new car. Clutch feels a lot better but brakes are now spot on. Prior to this is was convinced there was air in the system !!

Offline rowlers

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Re: Brake Pedal feel
« Reply #7 on: 02 February 2025, 15:57 »
I had this exact same issue. New discs, pads and brake fluid change but brakes always felt a little spongey and occasionally worse. Changed the master cylinder which apparently on our golfs runs both the brakes and clutch(so i was told ?) and it feels like a new car. Clutch feels a lot better but brakes are now spot on. Prior to this is was convinced there was air in the system !!

Yeah, I'm leaning towards having to change the MC. Did you change to servo as well?

Offline Ian Mack

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Re: Brake Pedal feel
« Reply #8 on: 04 February 2025, 11:23 »
Hi Mate,

No I just changed the MC. Hope it resolves your issues

Offline rowlers

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Re: Brake Pedal feel
« Reply #9 on: 05 February 2025, 15:48 »
Hi Mate,

No I just changed the MC. Hope it resolves your issues
Thanks