2003 Z4 top problems

**RogerC493** · 01-23-2019, 11:59 AM

When I press the "down" button, the top unlatches at the windshield but the top will not retract. I can hear the motor behind my seat running. The top can be manually pushed down and the cover flap closes. When I press the "up" button, I hear the motor running but it does not raise the top. So, I have the red bypass lever pulled and locked to by pass the pump. This makes raising the top manually much easier. Once the top is raised, I can press the "up" button and the top will latch to the windshield.
Does this sound like the hydraulic fluid is low? Can the pump be exposed without complete removal of the top?

**Muzz258** · 01-23-2019, 02:46 PM

Hi

If the fluid is low, there should be partial movement until the pump runs out of fluid. If the pump is out of fluid, then you would have the symptoms that you are experiencing. You will need to find the fluid leak and fix it before refilling the hydro unit.

Suggest that you do pull the complete soft top. That way you can easily see all of the hydro lines etc to find the leak. There are several You Tube videos on how to remove the soft top.

To answer your question about getting access to the motor/hydro without taking the top off. Yes it can be done. Search on "Z4 soft top motor relocation" and you'll find tips on this job.

**JAS1169** · 01-23-2019, 07:58 PM

Muzz258 advise is 100% correct.

It is my understanding that if your rack in the trunk is in the up position the roof will not even unlock. Since your roof is unlocking from the frame of the windshield I don't think it's the trunk rack.

I did the Z4 motor relocation thru the trunk. I did so because I had the "daily double" both my motor and the red emergency release cable were both shot. However, this method is only used to change out the motor and then relocated it to the trunk. This method can't identify the location of a hydo leak. As suggested by MUZZ258, the top should be pulled and then tested off the car where the hydo system is visionally exposed to id the source of the leak.

After locating and fixing the leak, I would recommend relocating the motor to the trunk when you reinstall the top.

**RogerC493** · 01-25-2019, 11:21 PM

My top shelf is in the down position.

So if the motor runs, the problem has to be with the hydraulic lines? How is the relocated pump motor attached in the trunk? Can you post a pic?

**carlsson01** · 01-26-2019, 12:52 PM

Hi RogerC493,did the top removal on my z4 two days ago...removing the top is easy...it’s the putting it back that gave me so much frustration. Maybe others found doing it easy...I was also experiencing same symptoms as you...found out i had a leak in one of the hydraulic cylinders...very expensive to replace. Anyway good luck on your endeavor..

**tekoo** · 01-26-2019, 02:07 PM

Everyone with soft top problems; please check our extensive soft top troubleshooting thread. You should be able to find instant answers for all your questions and very useful DIYs, images and links.

https://www.bimmerforums.com/forum/s...-Z4-Roof-issue

https://www.bimmerforums.com/forum/s...26%23129303%3B

**JAS1169** · 01-26-2019, 07:14 PM

Originally Posted by carlsson01

Hi RogerC493,did the top removal on my z4 two days ago...removing the top is easy...it’s the putting it back that gave me so much frustration. Maybe others found doing it easy...I was also experiencing same symptoms as you...found out i had a leak in one of the hydraulic cylinders...very expensive to replace. Anyway good luck on your endeavor..

Hey, here's a link to a business that rebuilds convertable hydraulic cylinders cabriolethydraulics.com/convertible-top-cylinders.php

Although, I never use them for this service, it's my understand that getting one of these rebuilt isn't as costly as new. So if you chose to "do it again" at least you have a source which isn't nearly as costly as buying new lifters.

**carlsson01** · 01-27-2019, 12:01 PM

Thanks for the tip JAS1169....but know anyone doing same service in california?

**JAS1169** · 01-28-2019, 08:19 PM

Originally Posted by carlsson01

Thanks for the tip JAS1169....but know anyone doing same service in california?

Well, not sure why, since you got to ship them either way you do it....but, Oregon is the best I can do..

https://www.tophydraulicsinc.com/en/7-mercedes-benz

This vendor offers just about the same thing as the other vender I listed in my prior posting. Anyway, you now have source's to save $$$ if you want to give it another shot.