Convertible Top Hydraulic Fluid/Oil Type

Dynamics99 · 08-11-2021, 03:51 PM

Hi,

I replaced my hydraulic pump motor and the fluid reservoir is quite low so the top struggles to retract. I saw advance auto/auto zone are offering pentosin chf 202 but is there a specific type of fluid I need to use?

Is there a procedure to add in fluid (if I need to run it through several times etc...)?

zed_fan · 08-11-2021, 06:13 PM

OEM is yellow hydraulic fluid https://www.ecstuning.com/BMW-Z4-M_R...h/54340394395/
I used pentosin CHF 11s no problem since I had it on hand and it works just fine.

To fill just unscrew the bolt on top and add fluid with a syringe. I believe the system is self bleeding so just cycle it a few times and should be good to go.

Dynamics99 · 08-11-2021, 08:12 PM

I ended up using Pentosin CHF 202. The reservoir seems to hold fine as of now. I made sure the hydraulic lines are not twisted or bent. Bowden cable works fine. I hid the motor with the carpet and put the shelf back. The roof goes to the closed position(roof is up) just fine but it struggles to come down from the closed position. The latch works and the motor spins but the roof does not go anywhere. Also when the roof comes up it sort of bangs on the windshield area which I hate. I sprayed WD-40 on the hinges and let it sit for a half-hour but no luck. Would the actuators be shot or should I check each individual line.

zed_fan · 08-11-2021, 09:58 PM

Hm it probably wants a little more fluid. Also make sure the motor is upright as possible when testing. Other than that the other failure point is the hinges can leak but you would notice the fluid level going down or fluid near your rear tires.

The roof slam is due to worn tension cables that attach to the convertible frame, not sure if they can be replaced without removing the fabric.

Dynamics99 · 08-14-2021, 01:27 PM

Thanks zed_fan. I think I will put up with it. It just needs a small finger push to get the struggle out. Im only 23. I should not be complaining. Since it's garaged 24/7 I'll just have it in the down position.

08-11-2021, 03:51 PM	#1
Dynamics99 Private First Class 28 Rep 161 Posts Drives: 2011 E92 & E90 335i 6MT MSport Join Date: Oct 2019 Location: Philadelphia iTrader: (0)	Convertible Top Hydraulic Fluid/Oil Type Hi, I replaced my hydraulic pump motor and the fluid reservoir is quite low so the top struggles to retract. I saw advance auto/auto zone are offering pentosin chf 202 but is there a specific type of fluid I need to use? Is there a procedure to add in fluid (if I need to run it through several times etc...)?
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08-11-2021, 06:13 PM	#2
zed_fan Private 21 Rep 70 Posts Drives: 2006 Z4MR, E60 M5 6MT Join Date: Jul 2020 Location: AZ iTrader: (0)	OEM is yellow hydraulic fluid https://www.ecstuning.com/BMW-Z4-M_R...h/54340394395/ I used pentosin CHF 11s no problem since I had it on hand and it works just fine. To fill just unscrew the bolt on top and add fluid with a syringe. I believe the system is self bleeding so just cycle it a few times and should be good to go. Attached Images
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08-11-2021, 08:12 PM	#3
Dynamics99 Private First Class 28 Rep 161 Posts Drives: 2011 E92 & E90 335i 6MT MSport Join Date: Oct 2019 Location: Philadelphia iTrader: (0)	I ended up using Pentosin CHF 202. The reservoir seems to hold fine as of now. I made sure the hydraulic lines are not twisted or bent. Bowden cable works fine. I hid the motor with the carpet and put the shelf back. The roof goes to the closed position(roof is up) just fine but it struggles to come down from the closed position. The latch works and the motor spins but the roof does not go anywhere. Also when the roof comes up it sort of bangs on the windshield area which I hate. I sprayed WD-40 on the hinges and let it sit for a half-hour but no luck. Would the actuators be shot or should I check each individual line.
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08-11-2021, 09:58 PM	#4
zed_fan Private 21 Rep 70 Posts Drives: 2006 Z4MR, E60 M5 6MT Join Date: Jul 2020 Location: AZ iTrader: (0)	Hm it probably wants a little more fluid. Also make sure the motor is upright as possible when testing. Other than that the other failure point is the hinges can leak but you would notice the fluid level going down or fluid near your rear tires. The roof slam is due to worn tension cables that attach to the convertible frame, not sure if they can be replaced without removing the fabric.
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08-14-2021, 01:27 PM	#5
Dynamics99 Private First Class 28 Rep 161 Posts Drives: 2011 E92 & E90 335i 6MT MSport Join Date: Oct 2019 Location: Philadelphia iTrader: (0)	Thanks zed_fan. I think I will put up with it. It just needs a small finger push to get the struggle out. Im only 23. I should not be complaining. Since it's garaged 24/7 I'll just have it in the down position.
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