Roof problem

[henry974]

Hi there
I am new and French (sorry nobody is perfect) ; and I use google translator.
I have a 2003 z4 3.0l.


and since 6 months I have a problem (hydraulic I think) with my roof.
By dint of research I ended up ordering a new complete hydraulic unit but without success...
When I press the opening button the hooks unlock; the windows roll down I hear
engine but nothing happens.
I push it by hand freely until about 1/4 of the sequence and there the pump is finished
work without problem.
To close the roof begins to rise then falls suddenly as if there were
a pressure drop in the circuit.
The switch in the trunk is shunted; I did not reassemble the bowden cable;
I checked the harness at the front left of the roof,
I don't have a leak...I don't understand where my problem comes from?
Has anyone here encountered this error before?
In advance thank you for your help.
I attach 1 video to explain my concerns.



https://vimeo.com/773002614

[Jas- USA]

Henry

Your Video shows the roof dropping back after it stopped. Your hydraulic system can't be fully pressurized. 1st, check the red handle emergency by-pass in your trunk/boot. In that, it may be partially engaged which might cause your loss of pressure. I hope your top motor has been relocated into the trunk/boot. In that, you'll be able to check if the emergency release at the motor is jammed, as well as being able to check the hydraulic fluid level. The only other thing which could cause this sort of pressure loss is being low on Hydraulic fluid. Maybe one of your hinge lifters is leaking/seeping fluid.

[henry974]

Hello Jas and thank you
The bowden cable is not installed; I can thus check if the by-pass is activated or not.
When the roof is closed and I want to open it, I have no by-pass pressure; on the other hand when it is down and I start closing the bypass is hard.
My engine is currently in the trunk positioned horizontally while the repair is being carried out.
The level in the tank is good.
I have no apparent external leak, so I was also thinking of an internal leak. but why only for a moment and not all the time.
Moreover, although I have read several forums, I have never seen this type of problem.

[enuff_zed]

Hello Jas and thank you
The bowden cable is not installed; I can thus check if the by-pass is activated or not.
When the roof is closed and I want to open it, I have no by-pass pressure; on the other hand when it is down and I start closing the bypass is hard.
My engine is currently in the trunk positioned horizontally while the repair is being carried out.
The level in the tank is good.
I have no apparent external leak, so I was also thinking of an internal leak. but why only for a moment and not all the time.
Moreover, although I have read several forums, I have never seen this type of problem.

If it's horizontal that could be your problem.
If you only fill it to the + mark on the reservoir it will only work in the upright position.
At an angle the ports in the pump can be uncovered and suck in air.
Stand it upright and fill it up until fluid spills out the top. Then try it.
Don't put it at any more than a 45 degree angle. This is how they usually sit when relocated into the corner of the trunk.

[henry974]

Sorry I didn't read myself
the pump is in a vertical position

[enuff_zed]

Sorry I didn't read myself
the pump is in a vertical position

Ah. No quick fix then.
Fill it right up and see what happens anyway.
Then see if the fluid drops at all.
Sometimes, if air has got in it can take a few operations to self bleed.

[bigwinn]

Martin I’m thinking this looks like a loom break issue

Doesn’t work until it’s pushed- makes the connection?

[henry974]

I have already checked the electrical harness at the top of the roof and it is good.
To isolate the problem of the electrical harness I supplied 12 volts directly to the pump and the result is the same

[bigwinn]

Have you checked the harness along the right hand side down to the motor

That’s where my break was

[henry974]

My z4 is a left-hand drive, I checked the cable from the roof release motor to where I could in the soft top.
I did not look on the right side.
If this famous cable is cut does the engine continue to run or does it stop working?
Mine spins all the time.

[bigwinn]

Ah no a loom break is full stop of everything

If your pump still spins that’s not it

[bigwinn]

Re reading

I don’t think there is much left to check apart from

Check the motor has correct wire attachment +/-
Check the hydraulic hoses 11/13 and 12/14 are in the right order and right ports

I’d then be saying your pump head is on the way out

[henry974]

I changed the hydraulic group it is new
I have already reversed the hydraulic circuits and the connectors + and -

[Smartbear]

I changed the hydraulic group it is new
I have already reversed the hydraulic circuits and the connectors + and -

was it working before you worked on the pump?
Rob

[MikeyH]

Need I be the one to ask this? Are you operating the roof with the engine running? Mine is a bit like this when doing it from the battery sometimes and needs a little help to get it started.