Soft Top Hydraulic Pump - Relocate to Trunk

[dc_wright]

As part of my soft top refurbishment (new motor, new lift cylinders, new top, new head liner) I relocated the pump motor to the trunk. DIY instruction is attached.

[SaltyNC]

Originally Posted by dc_wright

As part of my soft top refurbishment (new motor, new lift cylinders, new top, new head liner) I relocated the pump motor to the trunk. DIY instruction is attached.

Awesome write-up, DC! Thanks for taking the time to do this for the community. I know the guy in Germany has done hundreds of these, and it's great to have some details on how to do it here in the states.

Salty

[dc_wright]

Originally Posted by SaltyNC

Awesome write-up, DC! Thanks for taking the time to do this for the community. I know the guy in Germany has done hundreds of these, and it's great to have some details on how to do it here in the states.

Salty

Thanks! I'm working on the DIYs for the top/headliner replacement and the lift cylinder replacement and will post them in the next week or so.

[ljkiter]

I'm excited about this DIY! Please post it when its done and also how to get the parts!

[dc_wright]

Originally Posted by ljkiter

I'm excited about this DIY! Please post it when its done and also how to get the parts!

If you're referencing the top motor relocation DIY, I posted it as an edit to my opening entry on this thread. Check my first post and you'll see the PDF file is available. I'm still working on the top and head liner replacement DIYs if those are what you're referencing.

[AppDreamer]

I have just finished a DIY on the soft top hydraulics, but I can't figure out how to get the Soft Top Floor re-attached. Does anyone have any micro-DIY for re-installing the Soft Top Floor in the trunk?

[NSummers]

damn i need to get this one.. been driving around without open top for 3 years

[SuperchargedZ4]

Thanks for this write up! About how long should this take? I don't have a garage so I'd hopefully be doing this all in my drive. I saw a guy in the UK now claims he can do these relocations in about 10 minutes, I'm sure it will be hours for me. He can also make the original motor come back to life, won't give any details on how for either, though, unfortunately.

[dc_wright]

Originally Posted by SuperchargedZ4

Thanks for this write up! About how long should this take? I don't have a garage so I'd hopefully be doing this all in my drive. I saw a guy in the UK now claims he can do these relocations in about 10 minutes, I'm sure it will be hours for me. He can also make the original motor come back to life, won't give any details on how for either, though, unfortunately.

I did the motor relocate while I was doing a top canvas, headliner, hydraulic cylinder, hydraulic pump replacement so I don't have a good estimate for doing just the pump relocate. Having had the top off the car a couple times now, I believe I could do the relocate without having to remove the top assembly, but I think it would take me a couple hours to do. There's a fellow in Germany that does the same thing as the UK chap, and I think they're quick because they don't make a clearance slot for the hydraulic lines. They just let them run through the seam where the tray holder meets the plastic for the drain funnel. The hydraulic lines are pretty stoutly built and what they do is probably OK, but I didn't like that idea which is why I faced the pump to the rear of the car and made the clearance slot for the lines. I was determined the top is not coming off the car again and a damaged hydraulic line requires a top removal if it's on the passenger side. (With the motor relocated there's room on the driver side to get to where the hydraulic lines attach to the lift cylinder.)

[rapidroy]

when i did my relocate of the pump i did it with the top on i had a small inspection camera and poked it down the hole and saw a tie strap holding the pump housing to the top frame i sharpened the end of a 1/4 inch steel rod about 12" long and cut the strap with it and then pulled the pump out, some people pull on the housing till the slot on the housing breaks. i also notched the plastic panel to let the hoses in the trunk. heres the pump i pulled out

[Z4Lee]

/\ very clever I can see that working well

[kaybat]

about to tackle this...

does the top module have to be moved, Or does it stay where it is? I assume the cable is long enough to reach the trunk?Thanks!

[dc_wright]

Originally Posted by kaybat

about to tackle this...

does the top module have to be moved, Or does it stay where it is? I assume the cable is long enough to reach the trunk?Thanks!

Cable is plenty long. There's a pass through hole in the rear bulkhead that allows you to route the harness from the top module straight back to the pocket where you'll mount the pump.

[kaybat]

My housing appears to have duct tape around it,which means the previous owner must have replaced it.

What a shitty design...what are/were they smoking over there? :-)

[pip_pill]

Not doing this yet, but great post thanks for making me feel better about having to relocate or replace the motor PDF saved away for early next year....

[dc_wright]

Originally Posted by kaybat

My housing appears to have duct tape around it,which means the previous owner must have replaced it.

What a shitty design...what are/were they smoking over there? :-)

It's my understanding BMW wanted the top assembly to be a modular design so that they could test it independently from the car, then drop it place, bolt in in and connect the electricals. They achieved that by mounting the motor to the left side hydraulic cylinder, but putting it inside the drain funnel instead of outside was truly boneheaded.

[Huz-Z]

Originally Posted by dc_wright

It's my understanding BMW wanted the top assembly to be a modular design so that they could test it independently from the car, then drop it place, bolt in in and connect the electricals. They achieved that by mounting the motor to the left side hydraulic cylinder, but putting it inside the drain funnel instead of outside was truly boneheaded.

As a mechanical engineer, I can say that this was clearly done to simplify manufacturing and reduce its cost. But it failed to address the impact on long term viability of the pump. I suspect that some factory bean counter had a study done to determine that while a high failure rate was likely, most failures would occur outside the warranty period with the repair cost borne by the customer.

[garto87]

So this was a lifesaver, my top went out this summer and I was hemming and hawing for about a month before I got the nerves to take it all apart.

One thing I'd like to mention is that I struggled getting the motor free. I ended up just removing all the bolts for the top and then pulled up on the drivers side to get the motor out, cut the zip ties/housing then swung the motor inside the turn before dropping back down. I didn't need to fully remove the top and was able to undo the bolts, release the motor, then put all the bolts back in within 2 hours. just make sure you tape up the back of the hoop bars so you don't ding them during the process.

Also once the i disassembled the motor housing, I removed the motor and washed it under the faucet and got all the gunk out. I let it dry for 2 days and it actually started back up, no lose of power or anything, and saved me $600 from buying a new unit. Well worth the effort.

In all this guide saved me about $2k from having to take it to a shop/dealer.

Thank you again!

[GuidoK]

Originally Posted by Huz-Z

As a mechanical engineer, I can say that this was clearly done to simplify manufacturing and reduce its cost. But it failed to address the impact on long term viability of the pump. I suspect that some factory bean counter had a study done to determine that while a high failure rate was likely, most failures would occur outside the warranty period with the repair cost borne by the customer.

Yes its done to make the roof install easier in the factory (it goes in as a complete unit).
But the real reason/cause the pump fails is not the location but the clogging of the draining holes. If they dont get clogged (by debris from trees and whatnot) there is no issue.

I have no idea what will be 2nd on the list to fail if drain holes get clogged. At one point that cavity has to overflood if the clogging continues and it keeps raining . Loads of other electric units in that area that can suffer damage; ULF, CD changer, speakers etc.

I wonder if the frequent clogging of those drain channels is due to that strange rubber grommet that sits on the underside of those channels.

[dc_wright]

Originally Posted by GuidoK

Yes its done to make the roof install easier in the factory (it goes in as a complete unit).
But the real reason/cause the pump fails is not the location but the clogging of the draining holes. If they dont get clogged (by debris from trees and whatnot) there is no issue.

I have no idea what will be 2nd on the list to fail if drain holes get clogged. At one point that cavity has to overflood if the clogging continues and it keeps raining . Loads of other electric units in that area that can suffer damage; ULF, CD changer, speakers etc.

I wonder if the frequent clogging of those drain channels is due to that strange rubber grommet that sits on the underside of those channels.

The rubber piece at the bottom of the drains is a one way valve to let water out and keep critters from coming back in. It doesn't help with the clogging issue for certain.

On pre-facelift cars that had the audio amp in the battery well, that's where the water collected when the drain funnels got clogged and overflowed. It killed the audio amp and the top motor. Post face lift the audio amp got moved to the passenger compartment rear bulkhead behind the carpet in the trunk. The other items that can get wet if the drains overflow are the top controller and the woofers. If one was really ignorant of what was going on in a pre-facelift car you could have water take out the top motor, the top controller, the audio amp, and both woofers. The cost to recover from that is mind boggling! Probably would be a figure that would lead one to scrap the car.

[GuidoK]

Originally Posted by dc_wright

The rubber piece at the bottom of the drains is a one way valve to let water out and keep critters from coming back in. It doesn't help with the clogging issue for certain.

I also have my doubts on if they do more good than wrong.
In any case it's sensible to periodically check if those drains are still unclogged/free of debris.

[dc_wright]

Originally Posted by GuidoK

I also have my doubts on if they do more good than wrong.
In any case it's sensible to periodically check if those drains are still unclogged/free of debris.

Mine have been off the car for at least two years now and no critter invasions so far. The car is garage kept, gets driven at least 2-3 times a week, and no winter storage since I'm in Florida. I could see may there might be some benefit if the car was stored long term outdoors, but even then I agree they probably do more harm than good.