Help figuring out spoiler operation

[myturbo]

I've got a spoiler that otherwise operates as it should, but throws a failure light to the dash.  I've moved, stopped and measured the height of the spoiler at each end at several positions in transit with no issues.  Iv'e bled the system.  There are no visible leaks.

 

The only thing left are the micro switches.  I assume this is the only signal to the DME (that is, assuming the current to the motor is not monitored).  Having understood the system as I described it, am I correct to assume the micro switches are the only other thing left? 

 

Here is how I expect the microswitches work.  The lower one closes a circuit when the spoiler is all the way down causing the motor to turn off.  The upper one opens the circuit indicating that the ram is all the way deployed and shuts off the motor.  Can I pull out the microswitches from their housing and operate them manually while someone operates the switch in the cockpit?  Any other suggestions?

[Loren]

Sometimes the hydraulics wear out (they can leak internally also) and even though the microswitches and motors work the spoiler is not lifted or lowered to its actual limits.

[myturbo]

I know the rams are not rebuildable, but is there a solution for the pump assembly?

[jpflip]

In the DIY section you will found this :https://www.renntech.org/forums/tutorials/article/252-the-porsche-996-twin-turbo-potential-issues/

Look at the spoiler deployment failure links and especially this one: http://rennlist.com/forums/996-turbo-forum/238455-996-tt-rear-spoiler-problems-help-3.html also this one!!!: http://rennlist.com/forums/996-turbo-forum/952041-casting-parts-for-wing-pump.html

Edited February 18, 2017 by jpflip

[pierre]

That's probably the beginning of the end. [emoji21]

I went for the Rennkit solution and wouldn't go back: http://rennkit.com

Sent from my HTC 10 using Tapatalk

[jporter]

I have a 2001 911 turbo with about 40k miles and the warning started to show up about a month ago when the spoiler was raised on the highway.  I could duplicate this by raising the spoiler with the button.  There were no signs of leaking fluid.  I removed the microswitch unit with the spoiler up and noticed some light dry crude on the metal part of the upper microswitch that touched the outer surface of the ram.  There was some light crud on ram - this was visible looking through the opening for the upper microswitch.  I cleaned both surfaces and put some WD40 on the contacting surfaces and the warning has not returned (yet).

 

I do have a question on the operation of the system.  Raising the spoiler with the button just requires pressing and releasing the switch and the spoiler raises and stops at the top (passenger side stops ever so slightly after the driver side and this made sense as a result of the location of the microswitches).  Lowering the spoiler with the button requires you to hold the button down to keep the spoiler lowering, but if I continue to hold the button down when it stops the motor seems to continue to run for something less than two seconds and then stops - is this how it is supposed to work with the button?

[jporter]

I just looked at the operation again and there is also a delay in the movement up after the motor starts.  When you push the button to move the spoiler up, there is a short delay of about 2 seconds when the motor is running and the spoiler starts to move up.  This is very similar to the delay for the motor to stop when the spoiler is going down.  It seems like there is a gap formed between the hydraulic system and the mechanical part of the spoiler when the spoiler is retracted.  This gap causes the delay when the spoiler is raised as the gap between the hydraulic system and the mechanical part of the spoiler must first be closed.  If I release the down button before the spoiler if fully retracted, there is no delay when you press the button to raise the spoiler.  The spoiler does appear to be fully raised when it is at the top.  Is the delay before the spoiler raises and after the spoiler fully retracts normal?

[myturbo]

On 2/20/2017 at 5:48 PM, jporter said:

I just looked at the operation again and there is also a delay in the movement up after the motor starts.  When you push the button to move the spoiler up, there is a short delay of about 2 seconds when the motor is running and the spoiler starts to move up.  This is very similar to the delay for the motor to stop when the spoiler is going down.  It seems like there is a gap formed between the hydraulic system and the mechanical part of the spoiler when the spoiler is retracted.  This gap causes the delay when the spoiler is raised as the gap between the hydraulic system and the mechanical part of the spoiler must first be closed.  If I release the down button before the spoiler if fully retracted, there is no delay when you press the button to raise the spoiler.  The spoiler does appear to be fully raised when it is at the top.  Is the delay before the spoiler raises and after the spoiler fully retracts normal?

With regard to the motor running after the spoiler is up or down, I noticed that on the bench when I was bleeding. I noticed that I had to run the pump much longer, before it it stopped during bleeding, than I did when the rams were connected and ran their full motion. I haven't taken the pump apart, nor am I experienced with the turbo spoilers, but here is my guess.  I think there is a lot more displacement in the pump that is required in the rams.  I think this is so that there is some allowed room to pump beyond what is required. Let me try to explain with an example using arbitrary numbers.  If the total travel of the pump is 10", and full ram motion requires only 6".  This means that there is 2" at either end that is not normally used for full transit of the rams.  However, if the ram micro switch does not turn off the pump at the required 6" excursion, it may take up some of that 2" cushion to make the additional displacement.  If one direction only needs 6", while the other direction needs 6.2", you will eventually chew up the 2" cushion.  Any thoughts on this?

[nmlss2006]

Very late on the topic, but it may help in the future: there is at least one company who will rebuild the factory ram system at a much lower price than the positively hilarious rennkit.com list (who even have the impudence of charging separately for dust boots...).

 

The company I found is down in FL : http://www.cabriolethydraulics.com/porsche-carrera-hydraulics.php 

 

The complete rebuild cost $650 a few years ago and they seem to have a good reputation.