2.8 roof hydraulic pump

[Newtricks]

Afternoon all,

My question is (hopefully) a really simple one......my roof needs the fluid topping up, when I bought it a few weeks back the roof had been disconnected (via the rod by the passenger seat, not the T bar on top of the pump). I’ve reconnected the rod, released the T bar - when the hood is down the fluid is low in the reservoir.

I’ve taken the pump out of the brackets, but not disconnected any hydraulic lines. I found a picture in a previous thread that showed the filler plug as an Allen bolt near the T bar - my pump doesn’t have that. Is the filler plug the Allen bolt on the base (sort of central)? Is this the only way of adding fluid, or can I add by disconnecting one or other of the hydraulic hose banjo bolts?

Apologies if this has been asked and answered before - I did search first - honest!

regards

Nick

 

[colb]

https://z4-forum.com/forum/viewtopic.php?t=78848
Plug on top of the plastic reservoir, only top up to the level mark on the side of the reservoir, there needs to be room left for the oil to circulate from the rams.

 

[Newtricks]

Hiya,

The plastic reservoir doesn’t have a plug on top of it;

 

[Newtricks]

I wondered whether the filler is the Allen screw beneath the black dot in this photo, the T bar release is just visible on the top for point of reference. If it is, this one appears fairly rounded off (I might be able to hammer an Allen key in far enough to seat it.....), hence my question about filling via a hose connection if getting the Allen bolt out fails miserably.

 

[colb]

https://www.bimmerforums.com/forum/...-Topping-up-fluid-in-roof-s-engine-little-ask
Picture in this link shows the allen head plug next to the BMW label on the side as the filler hole, you obviously have to have the reservoir upsidedown when you remove it or the fluid will escape. Top it up to the centre of the mark on the side of the reservoir, don't overfill it. As you don't have a filler plug on the plastic reservoir it will be a hex plug.

View: https://www.youtube.com/watch?v=Rf5a6MdyNrU

E46 in this link pump should be the same as yours.

 

[Newtricks]

Ah, that looks to be the same - cheers for that! I’ll give it a whirl and reply.

regards

Nick

 

[Newtricks]

That does seem to be the filler plug. I tried a tiny funnel to put fluid in through, and a small syringe but that failed miserably - there seems to be a pin/valve in the bottom Of the filler hole. I’ll try a small oil can that has a flexible pipe next - makes me wonder if BMW has some ‘service’ tool for this task.

 

[colb]

Lifted from another forum
'You fill from the bottom. There is a set screw undeneath the unit pretty much in line with the label. You have to partially disconnect the unit and turn it so you can fill from the bottom.

You will need to cycle your top operation to depressurize the system. Open top , then close. Turn "T" srew 1/2 turn to the left. Now partially disconnect unit so you can basically turn it upside down. Fill level info is correct. Reverse procedure. It is hydraulic fluid.'

When they say set screw they meen the Hex plug, shouldn't be anything like a valve in there just a hole to add the oil.

 

[Newtricks]

Thanks everyone for their input and encouragement - reckon I’d have chucked it in without it - in particular to Colb who took the time to trawl the various forums for info - top stuff.

After trying various things, I eventually took the pump out for a proper look. There is a pin at the bottom of that particular hole, it may be that oil can seep past it over time, or possible under pressure. I rang Graham at roofmotors.co.uk (Who offer a refurb service with guarantee) who turned out to be great, and gave me some brilliant insight and advice; firstly, it’s a later style pump, secondly, the oil Opie provided is not the right kind of oil, apparently it’s fine for Audi roofs (and probably others), but not ours - too thick. Correct oil can be sourced very cheaply (£10/litre) from Europarts and is part no; 963220150. The oil should be virtually colourless (mine most definitely was not (pic below) which indicates age related thickening), so after undoing the jubilee clip I carefully pulled the reservoir off (initially enough to drain the oil, then fully to clean out completely (I flushed with WD40)), I did by holding the base in a vice with soft jaws. Whilst I had it apart, I had a good look at it - the Allen bolt from my first pic is the filler - hole straight into the impeller chamber - sadly mine has been rounded off and looks to have had a TX socket forced in at some point. I’m currently attempting to find a replacement filler plug before getting the old one out any way that I can. Another thing Graham mentioned which might prove useful to us all is that the pumps and roof mechanism are pretty bullet proof, the pumps use no oil, and usually a low oil level is often the result of age related thickening which requires a full change rather than top up.

So much for cutting my Z3 teeth on a couple of simple tasks to build a bit of confidence before moving onto the big ticket items!

regards

Nick

 

[Steve Medlock]

 

[Newtricks]

OK, sourced a new filler plug - for info if anyone else finds themselves in a similar predicament is a Shouldered hydraulic blanking plug BSP 1/8th. Thumbs down to Hoerbiger (whose UK office is just down the road in Leeds) who refused any request for help (including a simple request for the thread size of the plug - be warned M10 does not fit). I got the old rounded off one out by hammering a TX socket in carefully.

I’ve plumbed the pump back in, and now need to fill the pump and test whether it has cured the roof lift/lower - we’ll see - maybe today if it ever stops raining.

pictures are of old and replacement plugs.

 

[Newtricks]

Just to add a postscript; filled the pump with the correct ZHM oil, I found using a small funnel and tilting the pump off vertical worked best for getting the oil in, after filling to the correct level I remounted the pump into the correct position and tried the roof - not a flicker! Checked the brake light switch was working - yes, uncounted the micro switch from the roof frame and checked the wiring for chafing/breaks. I remounted the micro switch with a view to checking current etc with a multi-tester as the next step, but tried the roof again - successfully! I can only assume the switch had temporarily stuck or was dirty. Raised and lowered the roof 6 or so times, and then checked the oil level in the pump - needed topping up. Raised and lowered the roof another 6 or so times, and topped the pump up for a second time (started suspecting some other hydraulic leak......), same procedure raising and lowering the roof. Checked the pump - oil level now fine.

I’m now moving onto Coolant flush, water pump, thermostat, fan etc replacement.