Quote:
Originally Posted by nalin007
I also couldn't remove the pump when i was trying to change clutch oil in my 5 gen haldex on my BMW f48.
I wonder if the removing of cross member on rear axle support would help to extract the pump. See picture attached.
With an oil suction syringe it is possible to extract only about 250 ml of oil from 520 ml that reside in the clutch. Haldex has several oil compartment and making pauses between oil suction (about 5 min) may help to extract more oil. The oil need some time to flow from one camera to another. Unfortunately, i didn't come to this idea when i was changing the oil.
As per TIS, even if you just want to top up the haldex oil to the maximum level you need to perform the air bleeding and clutch calibration . It is easily done if you have access to ISTA or another diagnostic software that support this operation.
I assume that the bleeding can be done by making the pump run for a minute by driving some kms, but to perform calibration you need specific software. I would't omit this step as it in some cases it is required for correct function of clutch. I suggest to do air bleeding first and the the calibration.
When i was performing the air bleeding and calibration i heard some discontinuous squeak produced by pump right at the end of each operation. Did someone experienced the same when doing it?
After 70 000 km the oil in haldex of my bmw was like a petrol. It is annoying that there is no way to drain the oil completely and easy remove the pump to clean its filter on BMW f48. I think it worth doing at least partial oil replacement though suction by syringe on every motor oil change if there is really no way to remove the pump.
Please, share your experience.
Complete workflow:
- Open screw plug
- Slowly top up the HOC Oil until it escapes from the opening.
- Wait for 5 minutes (The differential clutch consists of several oil compartments. In order to guarantee equal filling of the oil compartments, the waiting period must be strictly observed)
- Top up oil again.
- Tighten the screw plug hand-tight.
- Bleed the clutch of the rear axle differential
- wait at least 30 sec
- Calibrate the clutch
- Open screw plug (Oil must emerge from the opening)
- Renew the sealing
- Apply screw plug (10Nm).
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Could somebody confirm that procedure mentioned above - toping up oil in horizontal position - allows to put 520ml of fluid to the HOC unit ? I am asking becouse my mechanic changed fluid according the YT:
https://youtu.be/JBpFaFo3JCc?si=g-DKH_RsvGBE74kC and even after ISTA bleeding procedure he was able to put in only about 350ml of fluid.
As I've seen in ISTA manuals ( same as TIS ) BMW recommends to ( in simply words) unscrew HOC and swivel to the vertical position:
https://zapodaj.net/plik-4y6ev5zo32
Than ISTA says to fill HOC with oil in this position - it looks more possible to put there 520ml when filling plug is rotated -on the top of pan in this position - not on side :/
Right now my x1 is running on 350ml of fluid in HOC , no cells on the dash, nothing strange happens but I am worried if in long therm it can cause some damage to HOC clutch.