Rear spoiler cylinders
#1
Rear spoiler cylinders
I dissected a leaking rear spoiler hydraulic cylinder kindly donated by "Strathroy" for the purpose of rebuilding it and perhaps becoming the Czar of a rebuild venture. I think Strathroy deserves some serious credit for his contribution to the knowledge bank
As you can see from the attached photos, it is not a straight forward single acting hydraulic cylinder. The part we all see under the wing is really just a sliding pillar which encloses a small sealed brass hydraulic cylinder with a 1/4" push rod which is driven out by an internal piston. The push rod is loose and not connected to the piston except by compression of the spring. The brass cylinder is surrounded by a rather large and quite powerful return spring. The spring load is all held by that diminutive spring clip. The source of the fluid leaks is the seal inside this brass cylinder. The cylinder has its end caps sealed in place by having its circumference rolled down into mating depressions on the end caps. I can find no simple way to dismantle this rolled seal without destroying the brass cylinder tube. If this brass cylinder component is something that can be purchased then it would be feasible to rebuild from there. If this is not possible I might look into building my own substitute cylinders. Compressing that mother of a spring and getting the spring clips back in place would require creating a compression rig which allows access for spring clip pliers.
If you have a failed system and do not wish to pay the toll, you could replace the 1/4" rod with a longer one, throw away the pump etc. which achieves the same function as having the wing permanently extended.
I am looking at the feasibility of substituting electric actuators. I have found some 4" stroke 12v units that might fit.
Hoping I haven't lost all sense of balance in life..
Bob
As you can see from the attached photos, it is not a straight forward single acting hydraulic cylinder. The part we all see under the wing is really just a sliding pillar which encloses a small sealed brass hydraulic cylinder with a 1/4" push rod which is driven out by an internal piston. The push rod is loose and not connected to the piston except by compression of the spring. The brass cylinder is surrounded by a rather large and quite powerful return spring. The spring load is all held by that diminutive spring clip. The source of the fluid leaks is the seal inside this brass cylinder. The cylinder has its end caps sealed in place by having its circumference rolled down into mating depressions on the end caps. I can find no simple way to dismantle this rolled seal without destroying the brass cylinder tube. If this brass cylinder component is something that can be purchased then it would be feasible to rebuild from there. If this is not possible I might look into building my own substitute cylinders. Compressing that mother of a spring and getting the spring clips back in place would require creating a compression rig which allows access for spring clip pliers.
If you have a failed system and do not wish to pay the toll, you could replace the 1/4" rod with a longer one, throw away the pump etc. which achieves the same function as having the wing permanently extended.
I am looking at the feasibility of substituting electric actuators. I have found some 4" stroke 12v units that might fit.
Hoping I haven't lost all sense of balance in life..
Bob
Last edited by Webtool1; 03-20-2009 at 01:28 PM.
#2
Looking forward to your results- the aftermarket has missed this one so far. I am sure that producing a rebuildable replacement cylinder would be reasonable, but to me actuators make more sense.
#3
Odog:
This is the type of unit I am thinking of below, it might take a bit of bodging to create a mount, but it wouldn't be rocket science. I'd have to adapt the actuator rod to the P wing mounts too. The drives tend to be about double the stroke length in total overall length. The current P cylinders are about 8" overall so things are reasonably close. Oddly I have not found a 3 inch stroke unit that matches the P cylinder but 4 inch stroke is readily available. But hey, an extra inch of stroke can only be a good thing, right? Or we could get really carried away. I'm not sure how much mounting room there is as my ride is still boxed up waiting for spring.
This is the type of unit I am thinking of below, it might take a bit of bodging to create a mount, but it wouldn't be rocket science. I'd have to adapt the actuator rod to the P wing mounts too. The drives tend to be about double the stroke length in total overall length. The current P cylinders are about 8" overall so things are reasonably close. Oddly I have not found a 3 inch stroke unit that matches the P cylinder but 4 inch stroke is readily available. But hey, an extra inch of stroke can only be a good thing, right? Or we could get really carried away. I'm not sure how much mounting room there is as my ride is still boxed up waiting for spring.
#4
Webtool,
As you are looking at actuators...definitely check out the adjustable stop versions and pay careful attention to real rate of extension and load capabilities- I have researched this plenty for a similar application- pop up headlights on my 951. The actuators I have bought and measured (based on the sales brochures claims) typically under-delivered.
I'll dig up my best finds and pass them along.
Best!
As you are looking at actuators...definitely check out the adjustable stop versions and pay careful attention to real rate of extension and load capabilities- I have researched this plenty for a similar application- pop up headlights on my 951. The actuators I have bought and measured (based on the sales brochures claims) typically under-delivered.
I'll dig up my best finds and pass them along.
Best!
#5
Odog
Good point.
I had assumed because the wing is so very light at about 5 lbs (static). compared to the thrust rating of the actuators being anywhere from 25 to 100 lbs. each (x 2), that they would appear to be under no load. But what would the speed loads be like, specifically at the deployment speed?
As with all low voltage motor systems, it will be critical to provide adequate wire gauge.
Good point.
I had assumed because the wing is so very light at about 5 lbs (static). compared to the thrust rating of the actuators being anywhere from 25 to 100 lbs. each (x 2), that they would appear to be under no load. But what would the speed loads be like, specifically at the deployment speed?
As with all low voltage motor systems, it will be critical to provide adequate wire gauge.
Last edited by Webtool1; 03-20-2009 at 01:41 PM.
#7
Webtool1:
Any updates on this project? I'm picking up a 2002 TT with a spoiler leak next week.... looking for a cheap(er) solution than total replacement of rams.
Any updates on this project? I'm picking up a 2002 TT with a spoiler leak next week.... looking for a cheap(er) solution than total replacement of rams.
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#8
well igota be dreamin but i thought i pposted this info this am... do search (about 5months ago) a sixspeeder answere my question regarding this prob.. he injecyed a stop leak additive into the sys and it worked. try it it's freeif i still ad the info i'd post it for you good luck steve
#10
Steve - I did see your post earlier today, which prompted me to look for Webtool's thread on actually repairing/replacing the ram itself.
However, since Kirk's chimed in with some longevity data, it doesn't seem like sealer's a bad idea. I was worried that it would do further damage to other parts of the system if only a ram seal was bad (i.e. by softening seal materials elsewhere in the system), but 2 years is pretty good for a 'band-aid' fix.
Thanks to you both. Webtool - I'm still interested in hearing if you've come up with a more permanent fix either by repairing the ram seals or replacing the system outright with electric actuators.
However, since Kirk's chimed in with some longevity data, it doesn't seem like sealer's a bad idea. I was worried that it would do further damage to other parts of the system if only a ram seal was bad (i.e. by softening seal materials elsewhere in the system), but 2 years is pretty good for a 'band-aid' fix.
Thanks to you both. Webtool - I'm still interested in hearing if you've come up with a more permanent fix either by repairing the ram seals or replacing the system outright with electric actuators.
#11
I recently changed the fluid in my system at the recommended 20% Lucas addition. It didn't help a rat's a$$.
How much Lucas did you add to the pentosin ?
#14
Sorry to be late in reply.
I did not pursue the electric actuator any further.
It is my understanding that the factory internal cylinders can be replaced at a fairly reasonable cost. There is no simple way to rebuild them as the internal cylinder ends are rolled to fit the end caps. If you got fresh brass tube and set up a lathe to roll the ends into the end caps then it would be a simple matter of replacing a few inexpensive seals.
In a production situation it could be done but for onesy-twosies??
I also have a fear of pentosin spilling onto someones hot engine.
Bob
I did not pursue the electric actuator any further.
It is my understanding that the factory internal cylinders can be replaced at a fairly reasonable cost. There is no simple way to rebuild them as the internal cylinder ends are rolled to fit the end caps. If you got fresh brass tube and set up a lathe to roll the ends into the end caps then it would be a simple matter of replacing a few inexpensive seals.
In a production situation it could be done but for onesy-twosies??
I also have a fear of pentosin spilling onto someones hot engine.
Bob
#15
Sorry to be late in reply.
I did not pursue the electric actuator any further.
It is my understanding that the factory internal cylinders can be replaced at a fairly reasonable cost. There is no simple way to rebuild them as the internal cylinder ends are rolled to fit the end caps. If you got fresh brass tube and set up a lathe to roll the ends into the end caps then it would be a simple matter of replacing a few inexpensive seals.
In a production situation it could be done but for onesy-twosies??
I also have a fear of pentosin spilling onto someones hot engine.
Bob
I did not pursue the electric actuator any further.
It is my understanding that the factory internal cylinders can be replaced at a fairly reasonable cost. There is no simple way to rebuild them as the internal cylinder ends are rolled to fit the end caps. If you got fresh brass tube and set up a lathe to roll the ends into the end caps then it would be a simple matter of replacing a few inexpensive seals.
In a production situation it could be done but for onesy-twosies??
I also have a fear of pentosin spilling onto someones hot engine.
Bob
What kind of cost do you consider reasonable for the replacement cylinders? Maybe I'm talking to the wrong people. I've been quoted $300 apiece for the cylinders. For a component that has seen such a high failure rate that is adding insult to injury,
Thanks,
Dave