[studio54]

Hello,

i think i have the check valve problem on my 135i.

I read it can cause the hard brake pedal symptom prior to start.

I also noticed some strange issues, and i do not know if it's related :

- when idle, i have a vibration that i can hear/feel in the cabin, like it's coming from the driver side, it makes kind of plastics vibration noises from the feet and pedal area. Idle rpm seems lower than usual, like 600 rpms (instead of 650rpm), and will drop to 550 rpms if press and maintain the brake pedal. If i rev a bit to 700 or so, the vibration disapears.

Does the check valve leak can cause these problems?

I found a DIY to change the check valve gasket (and the hose too), it's not too expensive.

Thanks

[hellokitty]

I also have a stiff brake pedal.

[studio54]

Originally Posted by hellokitty

I also have a stiff brake pedal.

Yes, it seems that a lot of people have it.

I don't know how is it important to repair or just live with it.

Any thoughts ?

Update concerning my rpm droping when braking, it's only on hill, so i guess it's the hill assist that pump some power to maintain the brake for 1 or 2 seconds, so i believe it's normal.

Concerning vibration, i will take a video with the noise, it's like a dashboard rattle during idle (with AC ON or AC OFF) coming from under the steering wheel but not sure.

[hellokitty]

Originally Posted by studio54

Yes, it seems that a lot of people have it.

I don't know how is it important to repair or just live with it.

Any thoughts ?

Update concerning my rpm droping when braking, it's only on hill, so i guess it's the hill assist that pump some power to maintain the brake for 1 or 2 seconds, so i believe it's normal.

Concerning vibration, i will take a video with the noise, it's like a dashboard rattle during idle (with AC ON or AC OFF) coming from under the steering wheel but not sure.

Idk but I just got used to it so it didn't really bother me anymore.

Unless there is a safety reason to fixing the check valve, I'm just going to leave it and avoid the hassle of fixing it and potentially having the problem return haha

[studio54]

Originally Posted by hellokitty

Idk but I just got used to it so it didn't really bother me anymore.

Unless there is a safety reason to fixing the check valve, I'm just going to leave it and avoid the hassle of fixing it and potentially having the problem return haha

Hehe yes, apparently it's designed to return, i read a DIY of someone who instead of replacing the gasket, put some gasket material.

On mine, it takes approx 12 hours for the check valve to leak and the pedal become hard, so it's probably a small leak. The gasket isn't expensive, but the access is a bit tight.

I will probably repair it, but not in a hurry if it's ok like that.