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      04-28-2020, 04:01 PM   #1
cjmahone66
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convertible top motor pump connections & hinge

I dont want this to be a dealer bashing post, or a discussion on warranties. my technical question requires some background on the details of my ordeal at the dealership. The pertinent facts are that i took it to them to put on a new top because my rear window glass was shattered. The top functioned properly when i dropped it off.

When i go to pick it up, it doesn't work and they tell me i need new hydra motor pump. fine, they install that, i go back and the top still doesnt work. at this point they have billed insurance about $8k iirc. They want me to pitch in another $2k to replace the hydraulic lines because they say they are leaking. in our discussions, i feel like they are not using logic to diagnose this and loose confidence in their work and decide to take a look myself before throwing more parts and labor at it.

i used @[Shipkiller] DIY guide to remove the top and set it up on a stand to inspect functions. i run the hydra motor pump with a battery and immediately see the left actuator/cylinder (hinge) hissing air and puking fluids. (must have blown gaskets? going to send that off for rebuild.)

upon further inspection, i find the hydra lines have been hooked up to the wrong ports where the banjo bolt attaches them to the pump housing. example: lines marked 11 and 13 are actually bolted to the ports marked for lines 14 and 12 on the pump housing. also see that in pics i find of the hydra motor pump, the electrical connections on the bottom of the pump are green wire on the side of the hydro pressure release cable. thats the left side of the pump if youre holding it in your hand and looking straight at the banjo bolts. my pump was hooked up with the blue wire on the left side.

when the hydro lines where hooked up backwards, do you think that is what blew out the hinge seals? or can the pump really function hooked up either way?

if the hydra lines were hooked up backwards, could that be why they wired the pump backwards so it would cancel out and run correctly?

ive searched but cant find details on removing the hinge from the top assembly: can anyone point me towards instructions?

lastly, realOEM shows the hydro lines routing from driver side hinge to left banjo bolt port, and then passenger side hinge to right side ports on the pump. but my lines are run so that the lines that exit each hinge actually split up and then one goes to the left banjo bolt and the other to the right banjo bolt on the hydra pump. Is the pic on RealOEM wrong or misleading? can anyone confirm the routing of the hydro lines?

https://www.realoem.com/bmw/enUS/sho...diagId=54_0313

thanks in advance for any technical info/advice you have on the hydro motor pump functioning.
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      04-28-2020, 04:27 PM   #2
cjmahone66
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found this video on the hinge removal:


i guess i basically had it correct, just couldnt get that fat pin to push out. didnt want to break anything, but i got it now.
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      05-11-2020, 12:51 PM   #3
cjmahone66
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I sent off the driver's side actuator to Top Hydraulics in Oregon and they rebuilt and sent back. i put things back together, ended up deciding to run the hydro lines as marked on the pump (opposite of the way the dealership left them) and i was very excited to see the top ran perfectly.

when i came out the next morning to reinstall the top onto the car, i noticed the passenger side actuator was leaking! dang it, i should have sent them both actuators at the same time, but the passenger side didnt show signs of leaking until the drivers side was fixed.

so i sent off the passenger side for a rebuild and just waiting for that to come back.

Top Hydraulics seems pretty good so far, quick turnaround and rebuilt parts functions properly so far. and heck of a lot cheaper than buying new actuators/hinges.

i also decided to relocate the pump to the trunk, so it will be easy enough to figure out and switch the wiring to the pump.
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      05-27-2020, 08:53 AM   #4
cjmahone66
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just want to post this project is complete, in case this may help any future trouble shooters...

i did get the passenger side actuator/hinge back from Top Hydraulics and installed. filled up the system with fresh fluid and cycled it a couple times on the homemade stand and it seemed to work fine.

started to install it in the car and realized that even with the bypass cable pulled, the functioning was frozen. i was bummed, thought i had broken something. pulled it out and put back on the stand, finally realized it was hydro locked. i guess i overfilled it. easy fix though, i just loosened the fill screw on the motor and drained a little fluid, then cycled it several times by battery power and kept adding tiny amounts of fluid until it was just right. it seems to me that the fluid level should read full to the line while the top is completely compressed. i think i had originally filled it to the line while top was completely extended.

once i got that figured out, i installed it back in the car. took me a while just because i was real paranoid about the lines getting pinched so i went slow.

i relocated the motor to the trunk with the stock line lengths (Top Hydraulics sells lines that are 4" longer for this purpose.) it was tight, but it can be done if your careful. i would definitely suggest getting the extra long lines from Top Hydraulics if you plan to relocate, would make it so much easier/faster.

for future reference, if anyone else has had their hydro lines installed backwards (dealership installed mine backwards), they do need to be installed as indicated/numbered. on both actuators, the odd numbers plug into top port and even numbers plug into bottom port. example: driver's side actuator has line marked "11" on top port and "12" on bottom port. top port is the one held on with the clip, bottom one is held on with a tiny plate and screw.

as for the electrical leads to the motor, mine functions properly with the blue wire on the left side. that's the left side of the pump if you're holding it in your hand and looking straight at the banjo bolts.

wife is super happy her drop top works now, so i can get back to work on modding my Porsche.

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      07-15-2020, 08:37 AM   #5
rsutoratosu
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How did you cycle the fluid or bleed.. there is another user here asking, thanks !
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      07-16-2020, 05:56 PM   #6
cjmahone66
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Quote:
Originally Posted by rsutoratosu View Post
How did you cycle the fluid or bleed.. there is another user here asking, thanks !
the system is a self bleeding system, so all you have to do is fill it up and then cycle it several times while checking/filling until the level no longer changes and is at the desired level. i cycled the top while out of the car while on the homemade stand via 12 volt battery power.
the pump motor has an allen head screw on top of the white reservoir, that's where you can add fluid. i used a tiny funnel. my pump has a little line engraved in the reservoir and i filled it to that line. when i overfilled it, the whole system locked up. when that happened, i was able to loosen the screw and the system automatically pushed fluid out the fill hole.

hope that helps.

P.S.- the system needs to read full at the line when the top is compressed. the first time i filled it, i did so at the fully extended position, which is what led made it overfilled.

Last edited by cjmahone66; 07-16-2020 at 05:58 PM.. Reason: adding info
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