1000SFC Clutch pushrod piston rebuild?

Rockitdoc

Rockitdoc

Hero member
Location
Fort Collins, Colorado
So, my new to me SFC1000 was sitting a long time.  Corrosion in all hydraulics demands rebuilding.  Clutch lever moves and master cylinder seems to be ok (squirts liquid, at least) so I tried to bleed the clutch today and got milky foamy liquid out the bleed nipple.  Took case off and discovered the insides for the first time.  Question is:  how to remove the bit behind the rubber grommet that pushes on the clutch rod so I can see what needs replacing/restoring?  Picture below shows what I am having a hard time explaining in words:

P1000865_zpscf8114db.jpg


Thanks, in advance.

S
 
Use compressed air, just be sure not to watch the piston too closely, might hit you in the eye!!!  Place a rag over it and let it pop out.  Behind it you will find a (rusty?) spring, the sealing o-ring will surely show signs of wear.  Clean the spring up and replace the o-ring and you're good to go again.  Check the piston, if it is worn, replace it as well.

piet
 
sfcpiet said:
Use compressed air, just be sure not to watch the piston too closely, might hit you in the eye!!!  Place a rag over it and let it pop out.  Behind it you will find a (rusty?) spring, the sealing o-ring will surely show signs of wear.  Clean the spring up and replace the o-ring and you're good to go again.  Check the piston, if it is worn, replace it as well.

piet
Click to expand...

Thanks Piet,

But the piston is now part of the case, I think.  I tried air.  No way.  I heated the aluminum surrounding the piston and grabbed the piston with some pliers.  Doesn't even try to move!  Really stuck.  Try a machine shop next?  :(
 
nealebms said:
Try boiling it in a pan of water,works for caliper pistons.
Neale
Click to expand...

Boiled it for 20 minutes.  Piston is one with the case it seems.  I am assuming the piston is the darker gray item surrounding the ball bearing.  I grabbed it by the smaller raised circular piece surrounding the ball bearing and tried to turn it.  Doesn't budge.  Any other ideas?  I really don't want to crack the case.

 
Try filling it with a grease gun via the bleed nipple, if it's come loose that is, while warming the cover further with a hot air gun.  Bit of a mess, but about the only way to apply real pressure without breaking anything.

piet
 
Soak it in Plusgas over night and boil it some more.Be patient and it will eventually move.Rome was not built in a day as they say.and the covers are quite expensive secondhand.Good luck.
Neale
 
Try to push it in a bit first with a good tap to break the seal and get the piston moving then pump it out hydraulically using either the master cylinder or as suggested a grease gun.



  Keith
 
nealebms said:
Soak it in Plusgas over night and boil it some more.Be patient and it will eventually move.Rome was not built in a day as they say.and the covers are quite expensive secondhand.Good luck.
Neale
Click to expand...

Plusgas?  Do you know of an equivalent here in the Colonies? :)

S
 
Rockitdoc.. in the colonies..? whereforartthou..? We can help perhaps.
Take Keiths suggestion, that piston looks to be flush with the case, so will go in a good 5mm or so.. give it a good soak with something better than wd40.. there is a good product called liquid spanner out there. You will find that the seal has hardened and melded to the inner of the piston bore.. it is only a 4mm or so rubber ring.. just give a good tap, move it in, and then pump it out with the clutch lever..

HTH

8)
 
LaverdaIan said:
Rockitdoc.. in the colonies..? whereforartthou..? We can help perhaps.
Take Keiths suggestion, that piston looks to be flush with the case, so will go in a good 5mm or so.. give it a good soak with something better than wd40.. there is a good product called liquid spanner out there. You will find that the seal has hardened and melded to the inner of the piston bore.. it is only a 4mm or so rubber ring.. just give a good tap, move it in, and then pump it out with the clutch lever..

HTH

8)
Click to expand...

Northern Colorado.  I soaked it last night in Liquid Wrench, heated the case surrounding the piston and left it overnight.  Gonna wack it this morning to try and move it.  It is actually about 5mm below the edge of the case right now.
 
It doesn't look like you were below the rim when the picture was taken...did the piston move? compressed air really works but it looks like you have the hoses still attached, so trying to get it out hydraulically would be worth trying first. Be careful opening the bleed nipple you want to avoid breaking that, but its a good point to insert air...although I've always had the clutch line off and would recommend removing it.
 
Rockitdoc said:
Northern Colorado.  I soaked it last night in Liquid Wrench, heated the case surrounding the piston and left it overnight.  Gonna wack it this morning to try and move it.  It is actually about 5mm below the edge of the case right now.
Click to expand...

NO luck.  Wacked it and it MOVED!  But.........that took it back in the wrong direction, and now, it's stuck further down.  But.... it did move.  Hope... that's the thing! :-\
 
You're almost there...do you have access to a compressor? Remove the hose and blow the piston out using a rubber hose in between the casting and the nozzle. Put a towel over the piston...bang!! you're done!
 
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