jrp3168 Posted May 16, 2007 Share Posted May 16, 2007 Hello all.I just nearing the end of my brake overhaul. I've fitted new copperpipes, SS braided flexibles, new shoes& cylinders, new caliper seal and pads.Now I've come to the master cylinder and it looks like a problem.First there is some marking on the first shaft, the piece that is half in halfout. It looks like someones been at it with vise grips.There is a seal on this shaft but not a high pressure seal. Is this just to catch anything getting past the pressure seal?If so I may just get away with polishing the damage as there wasno signs of fluid leaking here.The bit thats got me stumped the the link between the 2 pistons.Mine has seperated as the clip that was fitted had come undone.The clip looks like a flat strip of metal (a bit like half a split pin)which I presume was wrapped around the pins on each piston.Is this normal or has someone been bodging?I presume the clip has to be bent in such a way that it is free toslide inside the pistons and allow them touch so the first pistonpushes the second. Then come out and pull the second piston backwhen the pedal is released.Looking at the parts, they would have to seperated anyway to fit the newseals. Are you supposed to unreavel the clip or drive the pins outof the pistonsHas anyone got any drawings or pictures of the cylinder. I've googles and searched the archives here but not found any.The BL manual doesnt have that much detail on the cylinder orrebuilding it. John Link to comment Share on other sites More sharing options...
Nigel Posted May 16, 2007 Share Posted May 16, 2007 I Had a bit of a drama rebuilding one of these master cylindersthe tiny roll pin I think you are referring to would not go back I ended up using something else to hold the spring loaded band inI cut to size a piece of a small allen key.Also the band that locates on the second (non roll pin end) became unattached and would not locate ( after struggling to get the pin in)so I had to use a part from another second hand M/Cyl that I had.So be aware of that. Link to comment Share on other sites More sharing options...
Vitesse2l Posted May 17, 2007 Share Posted May 17, 2007 Hi,I did this job recently.I don't think there is any problem with the marks you describe. This area is above the seals.Sounds like you got the deep circlip out OK. That caused me a bit of thought - I ground some cheap pliers until they fitted.The clip does look a bit crude, and as Nigel says, should be retained by the pins. Having extra arms helps when re-assembling. I removed the pins rather than undoing the clip.I would say be careful when assembling. You cant take the m/c apart without damaging the components. Guess you already know that though.Here is a link to a rebuild guide. For a Saab, but the mc is the same.http://www.vsaab.com/html/Articles/brakemaster.htmI managed to match the bits in my m/c to the diagram...cheers, Vitesse Link to comment Share on other sites More sharing options...
Vitesse2l Posted May 17, 2007 Share Posted May 17, 2007 Hi,I did this job recently.I don't think there is any problem with the marks you describe. This area is above the seals.Sounds like you got the deep circlip out OK. That caused me a bit of thought - I ground some cheap pliers until they fitted.The clip does look a bit crude, and as Nigel says, should be retained by the pins. Having extra arms helps when re-assembling. I removed the pins rather than undoing the clip.I would say be careful when assembling. You cant take the m/c apart without damaging the components. Guess you already know that though.Here is a link to a rebuild guide. For a Saab, but the mc is the same.http://www.vsaab.com/html/Articles/brakemaster.htmI managed to match the bits in my m/c to the diagram...cheers, Vitesse Link to comment Share on other sites More sharing options...
mikeyb Posted May 17, 2007 Share Posted May 17, 2007 excellent link, thanks for that! I have a part dismantled master cyl sitting on my bench, having come to a halt when I couldn't work out how to get the white plastic bearing out without buggering it! Now I know I have to bugger it to remove - damn, I was only intending to do a strip, clean, inspect and reassemble! Link to comment Share on other sites More sharing options...
jrp3168 Posted May 17, 2007 Author Share Posted May 17, 2007 Thanks for the help guys.The reason I thought it may have been bodged in thepast was the shape of the clip/band that links the 2 halves.I reckon now it was the original but it must have snapped andthen got mangled between the 2 pistons.Reading the SAAB website it refers to ensuring there is nodamage on the first piston twice so I'm even more dubiousabout the grip marks on mine now.I may have to take the plunge and get a new cylinder.John Link to comment Share on other sites More sharing options...
shenderson Posted May 18, 2007 Share Posted May 18, 2007 If you do take the plunge, I got mine from Past Parts in Bury St Edmunds - www.pastparts.co.uk - they do an exchange service for about £100. They reclaim cylinders by reboring and sleeving. Much cheaper than some other suppliers.Steve Link to comment Share on other sites More sharing options...
mikeyb Posted May 18, 2007 Share Posted May 18, 2007 Quite a few on Ebay from differnt suppliers with a buy it now of £125 also!Can recommend Past Parts though!Not sure what to do with mine now - just wanted to give it a good clean out and inspection as part of re-commissioning the brakes for an MOT after a 10 year lay up.Didn't want to fully overhaul at this stage as I'm planning a full brake system re-seal and conversion to silicone fluid AFTER the MOT as part of the 10CR prep. May just have to flush the best I can without further dismantling now and refit! Link to comment Share on other sites More sharing options...
ferds Posted May 18, 2007 Share Posted May 18, 2007 ... have to admit I attempted this 3 times, and the realised the bore was worn. :-/It looked perfect though. :(I then swapped it for a re-sleeved (using stainless) refurbished version from Tony Hart.Problem solved! ;DRegards,Chris Link to comment Share on other sites More sharing options...
StagByTriumph Posted May 23, 2007 Share Posted May 23, 2007 [quote by=jrp3168 link=Blah.pl?b=stag,m=1179348012,s=0 date=1179348012]Hello all.I just nearing the end of my brake overhaulNow I've come to the master cylinder and it looks like a problem.First there is some marking on the first shaft, John[/quote]So does anyone know where there may be a pile of NOS or new primary master cylinder pistons? I see this all the time, the primary piston shaft buggered up either with clamping jaws or from a drill bit drilling out the nylon washer.These have been NLS for many years now. Maybe this is something SOCTFL can encourage someone to make a batch. Link to comment Share on other sites More sharing options...
jrp3168 Posted May 25, 2007 Author Share Posted May 25, 2007 Well, I've now got a shiney new Lucas one from Tony Hart, around £140 delivered.I decided against the past parts re-sleeve as the bore looked OK, the damagewas to the pistons.Now that I've got a effectively complete new system I think I'll try Silicone fluid.I've tried Halfords, most of the other car shops in town and a few petrol stationsand boy is that stuff rare. I've had to resort to ebay.Is strange how everyone mentions struggling with the plastic washer my just fell outafter a few taps upside down.The bit that did baffle me was the second circlip hiding behind the oil seal.If there is a shortage of pistons out there I cant see why you can re-sleeve the piston shaft, just like the bore, but then I'm no expert and if new items areavailable for just a little more than re-cons it doesnt seem worth bothering.John Link to comment Share on other sites More sharing options...
StagByTriumph Posted May 29, 2007 Share Posted May 29, 2007 [quote by=jrp3168 link=Blah.pl?b=stag,m=1179348012,s=9 date=1180117490]Well, I've now got a shiney new Lucas one from Tony Hart, around £140 delivered.If there is a shortage of pistons out there I cant see why you can re-sleeve the piston shaft, just like the bore, but then I'm no expert and if new items areavailable for just a little more than re-cons it doesnt seem worth bothering.John[/quote]£140 that is for the whole MC unit complete, yes? Resleeved units are about 1/2 to 2/3 cost of NOS if I recall correctly.When a MC is resleeved, it is first bored oversize then a sleeve pressed and glued in place to get it back to original internal diameter. The Stag MC takes two sleeves.Some of my members take the scored pistons, braze them and lathe turn/polish them back to original OD. That seems to work well. Sleeving an MC piston ... I have to think about that. Link to comment Share on other sites More sharing options...
jrp3168 Posted May 29, 2007 Author Share Posted May 29, 2007 [quote by=StagByTriumph link=Blah.pl?b=stag,m=1179348012,s=10 date=1180473646]£140 that is for the whole MC unit complete, yes? Resleeved units are about 1/2 to 2/3 cost of NOS if I recall correctly.When a MC is resleeved, it is first bored oversize then a sleeve pressed and glued in place to get it back to original internal diameter. The Stag MC takes two sleeves.Some of my members take the scored pistons, braze them and lathe turn/polish them back to original OD. That seems to work well. Sleeving an MC piston ... I have to think about that.[/quote]Yes, it was a complete MC seehttp://cgi.ebay.co.uk/Triumph-Stag-NEW-Lucas-brake-master-cylinder_W0QQitemZ220114253169QQihZ012QQcategoryZ27383QQrdZ1QQssPageNameZWD1VQQcmdZViewItemIts now fitted and just awaiting fluid. The only difference I can see is thatit is branded LUCAS not LOCKHEED.Steve above advised a re-sleeved unit was around £100, for me the extra£30 or so buys me piece of mind. Brakes arent something I want to compromiseon.John Link to comment Share on other sites More sharing options...
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