Hydraulic center stand overhaul pics

[pozo_izquierdo]

Hi all,

today I took my hydraulic center stand actuator apart after five years of riding. The reason for this was that it sometimes would not work - especially when engine was warm. For whatever reason...

Anyway, it certainly was due time to service the unit. Both the electric motor and the whole hydraukic circuit. The hydraulic oil must have had a 50% water content..:p .

Anyway, here is a story on this project.

http://picasaweb.google.com/pozoizquierdo/HYDRAULICCENTERSTANDOVERHAUL#

I did mine the hard way = removed the whole center stand / side stand assembly, which really is not necessary. The actuator itself with it's frame comes out as such, too.

Now the unit has even a totally different sound, like when the bike was new...:)

Regards

[jzeiler]

Great pics Ari. You went further than I did, as I did not get into the pump. Be careful when you re-fill as you must have a small air pocket or that formed 0.030" o-ring will blow out of the case halves. I did it twice.

I finally filled it correctly and have had no problems. I added oil and cycled it on the bench in a horizontal position (much like it is on the bike) until I had full travel of the piston. Then I added a small amount of oil at a time until I could finally hear the relief valve open at the end of travel. Then I re-installed it and no more blow out of the o-ring.

[pozo_izquierdo]

Great pics Ari. You went further than I did, as I did not get into the pump. Be careful when you re-fill as you must have a small air pocket or that formed 0.030" o-ring will blow out of the case halves. I did it twice.

I finally filled it correctly and have had no problems. I added oil and cycled it on the bench in a horizontal position (much like it is on the bike) until I had full travel of the piston. Then I added a small amount of oil at a time until I could finally hear the relief valve open at the end of travel. Then I re-installed it and no more blow out of the o-ring.

Hi John,
thanks for your comments! My filling method was pretty much trial and error.
I also cycled the pump on the bench but this relief valve opening is news to me.
Actually I did my overhaul in such way that I first took the motor apart, cleaned it and reinstalled it. I was already about to put it back in the bike but then I bit the bullet and decided to peek inside the hydraulics as well. When testing it (with old oil inside) the piston went all the way in and I did not see / hear any relief valve go off. The motor sound just changed as if it was pushing against the wall.
Now with the new oil inside it does the same...At what stage did you blow your formed O-ring? During bench testing or in the bike? I'm wondering what actually should happen when the piston has gone all the way in and you just keep on running the pump.
I filled my oil as you did. I added the oil from all possible openings. Run the motor in between and added more and so on. So the O-ring blowing is a result of overfill I guess...

Regards

[simoncharles]

Excellent Ari ! Thanks a lot.

Just out of interest, how long did it take you ?.

Simon

[pozo_izquierdo]

Excellent Ari ! Thanks a lot.

Just out of interest, how long did it take you ?.

Simon

As I removed the whole centerstand / sidestand assembly, which is not necessary it took me some 4-5 hours. But that includes all kinds of "researching" and documenting etc. Even removing the lower fairings is not 100 % necessary...

Now if I would do it over I would probably do it in 2 hours max.
It is also important to work in right order with the hydraulic unit dismantling:
1. Remove the electric motor and clean it but do not put it back yet
2. Drain the oil
3. Remove and overhaul the pump
4. Dismantle the cylinder
5. Dismantle and clean the main case

Assembly goes:
1. Put the main case togehter
2. Install the main cylinder
3. Install the hydraulic pump
4. Install the electric motor
5. Fill the oil.

Regards

[charlieg]

Thanks for the pics and the write-up Ari. My 05' with 115K on the clock is still working fine but does sound like it is getting a bit weak. Your pics will certainly make my job easier.

-Chuck-

[simoncharles]

Thanks Ari, note taken.

Was that with or without help from the dachshund ?.

[pozo_izquierdo]

Thanks Ari, note taken.

Was that with or without help from the dachshund ?.

Luckily our "Ippu" is not too keen on working in the garage with me. Probably too many not-so-nice smells so if he occasionally comes in to say hello he goes back out right away...:)

Regards

[jzeiler]

Ari,


The o-ring always blew out on the bike. I determined when the relief valve opened when the pitch changed at the end of the piston stroke on the bench. Before I had enough oil in the piston would stop but the pitch did not change. I stopped adding oil when the pitch changed at the end of piston travel.

I noticed a small leak after the first install and saw the o-ring "peeking" out of the case half. I just did an engine oil change following my 6,181 mile CCR trip and no leaks from the actuator.

Here is a pic of the place where the o-ring blew out and how I repaired it with RTV.

[pozo_izquierdo]

Ari,


The o-ring always blew out on the bike. I determined when the relief valve opened when the pitch changed at the end of the piston stroke on the bench. Before I had enough oil in the piston would stop but the pitch did not change. I stopped adding oil when the pitch changed at the end of piston travel.

I noticed a small leak after the first install and saw the o-ring "peeking" out of the case half. I just did an engine oil change following my 6,181 mile CCR trip and no leaks from the actuator.

Here is a pic of the place where the o-ring blew out and how I repaired it with RTV.

John, thanks for the info. Just to make sure I have understood...So you say that the blowing of the O-ring was a result of too little oil in the system and not from overfilling? Actually when the system is installed in the bike there is the little (limit)switch in the centerstand that cuts the power from the actuator motor so the pump is not really "pushing against the wall" when installed.
Regards

[jzeiler]

Too much oil. Despite the limit switch the pressure builds up in the "reservoir" and blew out the o-ring. Joe even experienced it after several weeks of normal operation following his documented re-fill. It just builds up too much pressure in the reservoir if there is no air pocket. Maybe you got lucky by measuring the oil for your re-fill.

[tonygret]

That was one of the most comprehensive, well laid out posts I have seen on any forum. You have the patience of a saint! Great job!

[pozo_izquierdo]

Too much oil. Despite the limit switch the pressure builds up in the "reservoir" and blew out the o-ring. Joe even experienced it after several weeks of normal operation following his documented re-fill. It just builds up too much pressure in the reservoir if there is no air pocket. Maybe you got lucky by measuring the oil for your re-fill.

OK, John all clear now, thanks. I think I will add a word of warning to my work procedures. So let's not overfill! Looks like I was lucky with my filling, so far at least...:o

Sorry my ignorance but who is Joe you are referring to and where can his documented re-fill be found. I hate to leave unclear instructions to my pic site...

That was one of the most comprehensive, well laid out posts I have seen on any forum. You have the patience of a saint! Great job!

Thanks Tony for your kind words...:) My patience is often pretty far from any saint's but I figured why not take some pics while I was at it. This might encourage somebody else to attack the same project which really is not so complicated as you might expect.


Regards

[jzeiler]

Here is the link to Joe's article:


Link (http://www.bmwlt.com/files/displayimage.php?album=15&pos=3)
He is the one that got me to flush it in the first place with his article.

[bflemingor]

Great post Ari - Thanks!!

[cfell]

Very well done, Ari... don't start working on these things for the money.... I suspect you won't make any...because you will be so meticulous... but you'll have no problem getting additional clients!!!!

[2002redrider]

Great post, Ari. Very detailed with great photos. Yet another reason why I wouldn't want an auto center stand. That repair is so far over my head and I sure wouldn't want to pay the dealer to do it!

[ltride]

The dealer will not do it . He will only sell you a new unit!

[sully2028]

Ari,
Great article and pictures. Is there any way to get a copy of the pictures? Can they be posted in the HOW?
Thanks,

[pozo_izquierdo]

Hi all, and thanks to everyone for the nice comments. And special thanks to John who directed me to the instructions done by Joe Gottberg. He had a much more professional way of doing the oil filling. :bowdown: And as usual I found those instructions AFTER doing my own by trial and error..:p Anyway, I added the link to Joe's instructions to my picture text.

So, to my disappointment my center stand malfunction is not totally over:( . It still does the same thing as before the overhaul: Right after riding when I push the centerstand button, the yellow light in the dash blinks fast and that is all what happens. The centerstand will not go down. :confused:
Usually when I let the bike sit on the side stand for 2 - 3 minutes and try again the center stand works...
Does anyone happen to have the electric diagaram of the centerstand?

And I clarify the problem: I know that if I I press the brake or if the bike moves or if it is on gear there will a exclamation mark blinking on the dash (next to the gear indicator) telling me why the center stand will not deploy. (I have had that happen as well and then I have had the brake lever slightly pulled - enough for the micro switch to activate..)

But in my regular problem case there is no exclamation mark blinking, just the yellow centerstand light blinking fast...

Still confused but on a higher level...Any thoughts or similar experiences from anyone?

Regards

[jzeiler]

Ari,

The diagrams are no help. I think the controller has a current sense circuit that triggers on heat of the internal conductor. As you saw there is no sensor on the motor or pump unit. This was designed to disable the pump is you actuated it too many time in succession with out time for the motor to cool down.
I have not disassembled one to verify it yet. If that is the case that would explain why so many people have this trouble as engine heat is affecting it. Any one that has replaced an EHCS controller and has a bad one lying around, we would like to tear it apart.

[joegottberg]

Hi Ari,

I read your post about your centerstand. All I can say is WOW. You've done an awesome job. Terrible thing it is still giving trouble. I hate to say I'm getting real good at pulling mine on and off. The method I use is to drop the entire frame (skid plate actuator and all), then bench disassemble. You can overfill it and blow out the gasket (formed O-Ring) seal as Johna nd I can guarentee.

I understand there is a current sensor as John mentioned. I haven't seen it or worked with it. It has to be "upstream" of the connector. Feels like a lot of tupperware needs to come off to see it.

Looking at your motor, it is hard to imagine the sensor is really tripping. Your motor "brushes" are only slightly worn. I recently rebuilt one of the DC motors with only a paper thin brush. Had to use a modified spade connector. Worked for a short while and I got it back. I'll be digging into it this weekend.

I still am having trouble with your symptoms. If you are riding, I get the radiant heat thing from the engine causing problems with instrumentation, but, I can't imaging the unit cooling in a couple of minutes.

I have my center stand off right now. With everything "Normal" (no brakes, out of gear etc), when I push the button, the light (indicating the centerstand is deploying) blinks SLOWLY. When I put the brake on (or side stand down) it blinks FASTer.

Are you 100% sure there isn't some side stand microswitch malfunction?

Perhaps next time, just put the side stand down, then back up to see if this works?

Keep us informed of your symptoms.

I'll let you know if I find something as I put mine back together and can look at it more.

Good Luck.

Joe

[cfell]

Deputy5211 had similar problem.. turned out it was a problem with one of his LED brake lights...

[jzeiler]

I have to re-think the current based sensor as there is a relay fed by the controller that handles the motor load. It may just be a heat fault in the controller. Too bad we don't have info on the guts of the controller (which is up under the rear seat on the right side).

[pozo_izquierdo]

I have my center stand off right now. With everything "Normal" (no brakes, out of gear etc), when I push the button, the light (indicating the centerstand is deploying) blinks SLOWLY. When I put the brake on (or side stand down) it blinks FASTer.

Are you 100% sure there isn't some side stand microswitch malfunction?

Perhaps next time, just put the side stand down, then back up to see if this works?


Joe

Hi Joe, and thanks for your comments!
As I have learned, if any of EHCS no-go flags are on (brake applied, bike on gear, side stand down, bike moving) the little exclamation mark starts flashing on the left side of the gear indicator. Now in my case this feature works if I touch the brake handle for instance: The yellow EHCS light blinks fast and the exclamation mark flashes too.

Now, obviously, there is no other indicator for the "overheating" than the yellow EHCS light flashing at fast pace. So I must have this on when ever the unit will not work.

So, I guess I have to locate this control unit first and try to see if anything can be done to it...Thanks John for giving a hint of the location.:)
In case it is a sealed package there is not much a Sunday electrician like myself can do...:confused:

Deputy5211 had similar problem.. turned out it was a problem with one of his LED brake lights...

Channing, if I understand this correct, you are referring to Tony having installed some LED bulbs in place of the OEM bulbs. And this resulted to his EHCS not working... Sounds interesting. I have regular brake light bulbs but I have also some add-on LED brake lights, I have hooked up the center OEM bulb to work as brake light and rear fog light with a help of a diode. Plus I have a Dauntless hitch connector hooked up (without an isolator relay).
So I do have some "disturbing factors" in my brake light circuit if those really would affect the center stand function. However, all these I have had for quite some time already...:confused:


Regards

[joegottberg]

Ari,

Since my EHCS is disconnected (sitting on my work bench) my circuit is obviously "open".

I get the same symptome (fast blink of the lowering icon) when one of the interlocks is triggered. If I carry that observation forward, perhaps the relay John spoke about is defective on your bike? Could be a welded (or forced open) set of contacts? If you can open it up, you may just have to clean some "peaks and valleys" off the contacts?

Looking at your pictures, I cannot believe your motor is bad. I'll have to re-read your post, but, I assume you "hot wired" the EHCS while on the bench. Perhaps a hot-wire "rig" left connected to your EHCS while you ride, then switch it on while everything is "hot" will let you be 100% sure it is not your stand. I have a couple of spade connectors wired through a switch to a battery for testign works fine.

I'm betting the controller is bad. I've not heard of a "rash" of these failures, so perhaps a "wrecked" 05+ could be a source of a reasonably priced second hand one? I know there are many here (deputy5211 for one) who routinely have parted-out bikes. Perhaps a similar source exists closer to home?

Looks like you need to "tinker" a bit more. Fun Fun Fun ;)

Joe

[pozo_izquierdo]

As many of you who followed this thread remember that I did my EHCS overhaul in hoping that it would cure the mysterious problem of the pump motor sometimes not starting right after riding. The problems continued, however, although the EHCS overhaul was not wasted work after 5 seasons of riding.

Next I looked at the EHCS control box:
http://picasaweb.google.fi/pozoizquierdo/HYDRAULICCENTERSTANDCONTROLUNIT#

This looked pretty complicated for my skills so I touched nothing and put it back togehter. Dave (aka "Schweintechnik") gave me good advise how to look for cold solder joints but looks like I have found the reason for my problems elsewhere:

The problem seems to be the hand brake lever (or the microswitch in it). Every time the EHCS does not work after riding (or being "hot") I get it working by slightly pushing the hand brake lever outwards. So it looks like the hand brake microswitch or a retrun spring ir something is getting tired and the switch stays on even if I don't touch the brake.
During the winter I will take a closer look at the hand brake switch assembly and see if it only needs some lubrication.

So even if my EHCS is still not working in 50% of the time as supposed at least now I have a way to get it working in 100% of my trials.

Regards

[Hilton]

Good trouble shooting Ari. Yet another winter project ?

[jzeiler]

Ari,

Thanks for posting pictures of the unit - now I don't have to dissassemble mine!!!

Glad you finally figured out the cause of your problem.