RGS/RGA Front Brake Master Cylinder Overhaul.

M

Magnidec

Junior member
Location
Barry WALES UK. 🏴󠁧󠁢󠁷󠁬󠁳󠁿
Dear Members, I'm overhauling the front brake master cylinder on my 1985 RGA Laverda 1000 triple.
It's been removed from the handlebar and the lever has been taken off, as well as the plastic reservoir tank, the bare casting remains.
My question is….. How is the plunger piston and internals removed from the remaining casting ???
Any advice would be greatly appreciated.
Hoping to make Malcolm’s Willersey (U.K.) meeting at the start of August.
Thanks in advance to all.
Regards
Howard.

PS. Just scouring the site in case somebody else has asked, and it appears many have. The general answer seems to be…hit it out from the hose end using a small dia pin/drift.
To me that's a bit ambiguous. Do they mean the piston comes out at the hose end, TOWARD the bike, or
The piston comes out the other end AWAY from the bike.

Anyone else confirm, or have another way, before I set to it ???

IMG_8300.jpeg
 
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Magnidec said:
Dear Members, I'm overhauling the front brake master cylinder on my 1985 RGA Laverda 1000 triple.
It's been removed from the handlebar and the lever has been taken off, as well as the plastic reservoir tank, the bare casting remains.
My question is….. How is the plunger piston and internals removed from the remaining casting ???
Any advice would be greatly appreciated.
Hoping to make Malcolm’s Willersey (U.K.) meeting at the start of August.
Thanks in advance to all.
Regards
Howard.

PS. Just scouring the site in case somebody else has asked, and it appears many have. The general answer seems to be…hit it out from the hose end using a small dia pin/drift.
To me that's a bit ambiguous. Do they mean the piston comes out at the hose end, TOWARD the bike, or
The piston comes out the other end AWAY from the bike.

Anyone else confirm, or have another way, before I set to it ???

View attachment 91076
Click to expand...
Piston comes out lever side of course.
Paul
 
Thanks guys. Master cylinder is stripped and black shreds of O ring bits seem to be on the piston though the seals themselves appear intact. I’ve since found out that a FRONT overhaul kit is not available for my bike (1986 RGA)
Well, one is available called a PS15 (about £35 for the REAR) but the main piston is nothing like the one I’ve taken out of the FRONT unit. Mine has two long extensions (see pic) whereas the new kit has a piston with one long extension and a snub nose. I’m therefore assuming they're not transferable F to R. and I understand replacement complete master cylinder assemblies are made to order with no timescale available.
So, where do I go from here ?
Scouring the internet for a complete replacement but no luck so far.
Any suggestions what will fit ?
I can't be the first with a M/C overhaul problem.
Any advice gratefully received.
Howard

ps. I bought an incorrect 12mm kit thinking it was the correct size/shape piston which it obviously isn't. Strangely (or not) my piston, the larger one, has two seals, one tapered and one plain. It appears that replacement kits of any size may have two tapered O rings.
 

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Rob said:
Piston seldom needs replacing... just swap the seals over from a new kit of the correct size if you can't get hold of the front PS15
Click to expand...
Different sizes I'm afraid. Taper O ring 4mm not 4.2mm wide and I/D 9mm+ instead of 10mm+ Also I have one plain and one tapered but don't know if both should be tapered. Just established I may have a rare PS14 M/C in which case I may have found a solution. Thanks for your help anyway 👍
 
please contact www.octeam.de, they do speak english, too, and ship internationally. might take some time, but they have even new old stock (NOS) of the 1000 SFC rear master repair kits (just bought one from them for my bike), they might be able to serve you, too.
 
Laverdalothar said:
please contact www.octeam.de, they do speak english, too, and ship internationally. might take some time, but they have even new old stock (NOS) of the 1000 SFC rear master repair kits (just bought one from them for my bike), they might be able to serve you, too.
Click to expand...
Thanks for your advice. I think I’ve stumbled on the solution anyway. I thought the M/C were either 12mm or 15mm. Checking another site there appears to be a PS14mm version, which is what I have, and they have an overhaul kit available. Fingers crossed the problem can be sorted.
 
My RGS and SFC1000 both have the 14mm front master cylinder. Rebuild kits are available but not many are left. The same rebuild kit is used on a BMW R100RS and R100RT rear brake.
 
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