[oveleter]

Hello all. I have been attempting to diagnose brake issues with my 2020 330i x-Drive. Initially took it to the dealership and they said it was due to non-OEM pads (PowerStop). Given the symptoms (irregularity with braking pressure, slow acceleration at times, brakes thumping inconsistently), this seemed very unlikely. I went ahead and found a slightly used booster and master cylinder and completed that replacement myself. Symptoms improved, but still noticing some inconsistencies with braking pressure.

One of my family members is a mechanic and noted that he often replaces the check valve when trying to diagnose braking issues. I went and looked up some diagrams and found that the check value on the B46 engine is attached to the block (see snippet below from B46 service manual). Just from taking a peak in the engine bay, I don't see any direct access to this part. I was curious if anyone on these forums had completed one of these replacements and/or would have any idea how to access this to replace it.

Any input is appreciated.