Z4 Roof issue

[tekoo]

I am talking about the BANJO BOLTS themselves. They are identical and not marked. No Need to freak out about swapping them. The Kit comes with unmarked banjo bolts!

[celticrider]

So I am confused about the washers. If they are to be different, but still working on one function, like you say more than likely not the issue. I doubt if BMW parts will
Know anything about them as far as thickness, so not sure if I need to investigate further
The banjo bolts measured exactly the same, holes in same position, so not sure if an issue there but will switch the bolts.

[tekoo]

1-No, if there is no noticeable difference in washer size in your unit then I would not worry about washers.
2-The banjo bolts have a pin-sized entrance to their lumen so you will need to verify this pin size holes is patent and the bolts are not bent. The actual lumen of the bolt is actually much wider than the end hole. You will also need to torque the bolts to 12 Nm; no more, no less. (doublecheck the reference I linked in earlier posts with washer images).

If one of the bolts is over-torqued into the pump more than needed that could partially if not completely block all 3 holes!

[tekoo]

I have few questions for you:

1) During the defective/weak portion of the roof movement, does the MOTOR sound as if it was running out of battery (drained) ? Are there any sound changes at all?

2) Has the hydraulic fluid level been stable since the restored hinge got installed?

3) Has the roof ever functioned 100% at any point since you purchased this vehicle? If so for how long?

4) Have you irrigated the pump parts with alcohol and pumped compressed air in every valve and opening you can see (including pump openings where banjo bolts fit)? Compressed air is vital to get any particles/dirt dislodged from internal pump circuit that we can't see!

[celticrider]

1. The motor sounds free
when lowering and appears to sounding like it is working when it raises
It raises real fast , never been an issue.
When I switched the hoses those sounds changed from lower to raise as In free sounds raising and powerful lowering.
In fact it would not raise at all.
Just pump spinning free.
Had to pull bypass and lift manually.
3. When we bought the car, the dealer said the roof didn’t work.
He just took on trade.
They installed a new BMW pump
Shortly after we took possession,it started not locking when fully open, you would lift with the control then put back down and it would lock.
Then it started not lifting of windshield after unlocking.
You would have to give it a hand then it would go down to almost lock but wouldn’t at that point lifting and lowering wouldn’t lock it you had to physically push down to lock.
After reading several forums I thought it may be low in oil, and since the pump was in factory location I removed the roof.
After running it I noticed a cylinder leak, but reservoir was 1/2 full so it must have just started leaking.
So rebuilt cylinders were next.
2. Oil did not move in reservoir after bleeding and running several cycles.
4 have not irrigated. Would alcohol dry any seals that may be in the pump?
I can’t get a breakdown of the pump yet.
I took the valves apart and there is only a needle type plunger under the spring and adjustment screw, that’s it.
As far as the bolts I blew them out, very little air comes out either one.
There are plugs on the sides I think, not sure what they are.
I can’t even get my smallest tip cleaner in either banjo bolt when checking, I assume that is normal.
Answers 2 and 3 are screwed up.
Had all typed out and lost internet trying to submit.
Had to do all over, screwed up the answers

[tekoo]

When you say 'oil did not move', does that mean it has been stable or you are not seeing oil flow into the reservoir?

[celticrider]

Oil level did not drop after all Air was purged
Stayed at about 3/8-1/2” from
The top.

[tekoo]

Please, I asked you not to play with the valves until we run out of logical options!
You are resisting the more logical troubleshooting and getting stuck with dead-end stuff that has not even proven to be effective. I dissected the info/chat from the other forum to show you its B.S.and the guys have no clue what they are talking about.

If these valves get ruined or the plungers get stretched it will be game over!

If the pump worked well at one point there is no reason for valves/plunger to go bad or for valves to require re-adjustment of gauge/pressure. This pump is not designed to be serviced and therefore the rubber seals that you are pulling out may never work properly again.

What's more logic and common is that dirt/particles can precipitate and partially obstruct one of the internal channels where oil travels. I took my pump apart twice after installing it and every time the oil in the reservoir had accumulated enough precipitates that required fluid change and reservoir wipe down.
I promise you, alcohol will not ruin the rubber seals. I used alcohol, degreaser and compressed air to clean my pump! Multiple times! And my pump was out for weeks with no hydraulic oil whatsoever after I cleaned it.

How do you think I was able to take all these images of every part of my pump/motor assembly with no mess? It's because I irrigated air compressed and wiped off every part that I was able to access.

[tekoo]

Don't stick hard objects into the banjo bolts. The openings are very delicate and control the flow/pressure of hydraulic fluid. If the holes expands from the object you are inserting (even by 1 or 2 mms) it will cause a HUGE pressure change in the hydraulic lines and hinges.

Alcohol, compressed air are sufficient!

You can use the compressed air cans that are used to clean keyboards and electronics.

[tekoo]

There are 3-4 main things we still need to strike off the list:

1-structural defect in one of the banjo bolts -> we need to swap their positions to rule it out
2-dirt precipitates/partial blockage in the pump affecting the flow in one of the functional sides-> needs good irrigation and compressed air ( may need to separate the motor from the pump to confirm pump has been cleaned well in and out. However we need to go over few things before you separate the motor/pump). Taking the pump/motor apart will allow us to confirm the internal structure and mechanism is intact
3-We need to rule out isolated unidirectional pump weakness or motor weakness due to improper power supply.

As you can see we are not out of options yet so try to wait with the risky stuff till we give up on this pump.

[celticrider]

I understand and appreciate your logical advice.
I didn’t put anything in the banjo bolts other than air.
My tip cleaner wouldn’t go in.
So when you clean the pump, do you not need to dismantle what you can, the valves, plugs etc?
As for the motor or pump being bad, I might be missing something but if either were bad, would it not affect the roof in the opposite direction?
In my limited knowledge on this, it seems to be a oil pressure issue in one direction only, and as the same motor and pump pressure both directions and only the reversed polarity of the motor change oil direction then could we not eliminate the motor?
I realize the pump volume may be ok, but directing oil volume through the valves to enable pressure to build to what ever it’s supposed to be through the valves may be a possibility?
I don’t have your knowledge on these units,and I realize we have to eliminate one thing at a time to ensure we find what the actual problem was.

[celticrider]

So next step is to switch banjo bolts, test and if not bolt issue then do a voltage test on the power feeding the motor, then pump cleaning?

[tekoo]

Don’t touch the valves anymore. These might just be relief valves that deload the extra oil and air from circuit when pump is idle. As I explained before we have no diagrams that confirm where these valves lead to. When you separate the pump from motor you will realize you don’t see the valves from opposite side!

When I say take the pump apart I mean separate the pump from the motor. However before digging into that route I just want you to test the electrical wire first and make sure the pump is receiving a continuous and sustained 12 volt supply when you press each switch (open/close)

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Go back to the multimeter instructions from yesterday and perform that test. No need to connect the pump. Just test the wires!

[tekoo]

The voltage from these wires controls the magnetic fields inside the motor which in turn control the rotational force and speed of the motor. If the power supply to the motor is weaker/unstable on one side the motor may poorly function in one direction->causing weak/sluggish pump movement in one direction ->causing weak roof movement in one direction!

[celticrider]

Ok
Will check out and post the findings
Thanks again

[tekoo]

Each one of the 2 wires that supply the motor is deriving power from an independent relay! If one of these relays is weak or unstable the power supply from that specific relay will translate into weak/unstable motor function in one direction but not the other (the other one is getting good power from the healthy relay)!

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So we need to confirm each switch (open and close) when operational is delievering steady 12 volts to one of the wires in the motor harness!

[tekoo]

3. When we bought the car, the dealer said the roof didn’t work.
He just took on trade.
They installed a new BMW pump

Shortly after we took possession

,it started

not locking when fully open

, you would lift with the control then put back down and it would lock.
Then it started not lifting of windshield after unlocking.
You would have to give it a hand then it would

go down to almost lock but wouldn’t at that point

lifting and lowering wouldn’t lock it you had to

physically push down to lock

....

This locking problem in full open position is caused by the stowage lock mal-alignment.


The stowage lock is responsible for locking the roof in place after it has reached the end open position. In some vehicles this lock's alignment fails and leads to slight stowage lock protrusion which blocks the roof from landing into its proper end position (during the last few inches of roof opening).

The roof has built in electrical roof sensors that detect/confirm the roof has successfully reached the proper stowage (fully open) position and send signal to the pump/motor to stop moving. When the stowage lock problem occurs and the roof gets stuck overriding the stowage lock, the roof sensors never actually detect the roof has fully arrived/settled in the end open position. Since the sensors never get the confirmation they never send the signal to the motor to stop. So the motor keeps winding an winding (despite roof being stuck and not moving). When this occurs repeatedly it can lead to worn motor gear and motor failure. (internal bushings and gear of the motor get striped). As motor function deteriorates and the roof gets weaker and weaker, it's lack of performance progresses from problems only occurring during the last few inches of the roof travel (mechanical blockage), to problems occurring during raising the roof up which is the most power demanding portion for the motor during the opening procedure (motor failure/striped gear). After passing the heavy roof raising portion with some manual assistance (help or tap as you call it), gravity assists with the remaining portion of the roof descent even while the motor actually does so little if anything (if you open any Z4 roof halfway and leave it in the mid open position, gravity will slowly bring the roof down spontaneously to stowage position ; however it will occur much slower than if the motor was functional), However in your case gravity would bring the roof down till the last few inches where it gets blocked again overriding the stowage lock. And so on and so on..
When you 'physically push down to lock' you manually push the roof down allowing it to overcome the mechanical blockage by the stowage lock. The roof finally arrives to proper end position (below the stowage lock level) and the sensors send the signal and the useless motor stops.

You have to uninstall the stowage lock as I explained to you before (see link below). This lock is an independent unit from the roof and motor and the problem will remain and recur as long as the stowage lock is in place. Even if you replace the motor or fix this one, the protruding stowage lock will cause the same issue again and destroy the new/functional motor!!

We will keep our fingers crossed the motor did not sustain permanent damage from this!

When you say "shortly after we took possession..", How long is 'shortly'?

https://www.newtis.info/tisv2/a/en/e...ft-top/2pY0X3C

[celticrider]

Most times where the roof stops is 1-2” from where it locks, but at that time the roof light is out and motor is stopped, just not locked.
If you start driving the red light comes back on until you physically lock it.
As far as it damaging the motor, if it were weak,wouldn’t the lift cycle be affected as this takes way more effort to lift.
I have 1st hand experience when I switched the hoses and it would not lift.
We bought the car in late September and stored in October.
It was the following June or so after taking it out of storage in May it started screwing up.
The non BMW dealer is 4 hrs away, so taking it back was a pain.

[tekoo]

The motor is not designed to work under resistance or for extended periods of time. In fact; BMW recommends against opening and closing the roof more than 10 times per hour.
When motor works more than it should, it can get hot and fail (convertible top module detects overheating and temporarily cuts power supply to the motor until temp goes back to acceptable conditions).
When the car shakes/vibrates-> sensors re-discover the roof is not in proper final alignment/position and resend the signal to the control module to wake up and operate the motor (red light comes back on).
The motor and pump both have plastic gear inside that transmits the movement from the rotor of the motor to the spinning centrifugal pump part. If the plastic teeth or fitting get stripped in one direction the motor can still work okay in the other direction as the plastic is not worn out or striped in the other direction.

When you say the motor sounds ‘free’ during the defective portion of the movement, it could very well be that the motor is spinning freely as it’s disengaged from its striped gear in that direction.

Please test the power today and swap the bolts so we can strike the relays and banjo bolts off the list!

[tekoo]

I realize a video will be easier to see what is happening as my description lacks sometimes.
I mis spelled when I said it doesn’t look fully open. I meant it doesn’t lock fully open.
It closes fine always and lockes to the windshield always.
It unlocks from the windshield always but will not open by itself without some assistance most times, then after helping it open about 6” or so it will open the rest of the way by itself then stop about 2” from locking in the open position that’s when again you have to just put a bit of pressure to lock in the open position.
Funny thing is when i tested it out of the car, it opened fine.
Now it will open by itself only about 2 out of 10 times and never go low enough when fully open to lock in open position.

Can you explain to me how you tested the roof out of the car? How and where was it positioned and located? Which direction was it facing? What power was it connected to? Did you operate using the power switches? Was it connected to battery directly or did you plug it to its designated wiring? Where was the pump from the roof? Was the pump vertical in position or tilted? How many times did you test it? How many times did it open and close? At the end of each opening did it stop on its own or you stopped pressing power/disconnected wire?

[celticrider]

So did voltage test 12v with car off, ign on, 14v car running
When the roof was out of the car, I hooked 12v power direct to the motor, and switched wires to move different direction.
I only tried half dozen times with time in between testing.
I kept watch on the motor not to get hot.
I would open, then close then let sit for apr 5 minutes maybe
The roof was set up on a stand same direction as it fits on the car with the pump fastened to the stand in a vertical position
I stopped it at the end of its cycle because I assumed the stopping switching was in car harness, wasn’t sure so didn’t want to take a chance
I went until it just laboured slightly as it sounds when near windshield.
It did the same sound both directions as well as it appeared to have same sound of power both directions.

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Will do bolts later, will post results

[celticrider]

Just noticed something worth mentioning
I put oil in the reservoir before hooking lines up and oil comes out problem port almost right away.
If I block that port oil will come out the other but not unless I block the problem one?
May be nothing, though I could get some oil in so as less to put in in the trunk.

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When I look closer, oil comes out both, but 1st out of problem port.
I am referring to where the banjo bolts go in.

[tekoo]

Are you getting steady 12 volts in EACH wire separately? Does the 12 volt last as long as you are pressing the corresponding switch?

Please try to give precise and accurate confirmation answers to the tests. We don’t want to be chasing our tails!

[tekoo]

We already know there is power going to the motor since it runs!

The question we are trying to get an answer for:

1) is the power supply equally GOOD on EACH of the wires?
2) is the good power supply on each wire SUSTAINABLE/RELIABLE (lasts as long as we keep pressing each switch)?

[celticrider]

The power is consistent and lasting on each wire when switch is activated in each position.
Now I put the unit back in the trunk, switched banjo bolt locations and torqued to 12 nm and it works perfectly.
All except it will not lock, but goes much loser to the actual locking position.
When it goes down, sounds like it has power and when reaches down position, the motor stops and light is out.
It’s about 1/2” from being locked I assume by its position when down.
I don’t want to push on it as you said.