Master cylinder threads

[lnpab17]

Just bought 2 "upgraded" master cylinders on ebay. I am hoping the extra fluid shifted will improve gear changes, as clutch bites down at carpet level.
My problem has been that the pipe unscrewed ok from the old girling master cylinder,but it wouldn't pull clear once fully unscrewed. I gave it a good tug with pliers & it came free. The problem seemed to be that the flare was too large & fouling the threads. I carefully filed it down so that it clears the threads fine on the girling unit, but it still won't fit into the new one.
Is there more than one thread size? Or could it be that previous fitter reduced the thread profile by forcing wide flare down threads? That being the case, should I file away more flare until it fits?
The seller sells hundreds of these master cylinders & specified these for the Herald.
I've re-fitted the old one for now. The fluid was like soup, so maybe it will be improved!

3 hours of my 16 year old kangerooing & gearcrunching the Herald at the Car Drome made me realize that action is overdue!

[Pete Lewis]

yes there can be metric and imperial threads in cylinders  

if its a landy unit guess it could need a metric sleeve nut and a new flare

used on brakes the increase in bore to 0.75" will increase pedal load / reduce pad pressures compared to the 0,7 or 0.625"  depends whats original and which calipers you have .

low clutch operation probably needs repair to the pushrod clevis fork holes and the hole in the pedal ,

away from original but to raise the pedal start height you can slot the mounting bracket holes and slide the assy forwards to get a higher pedal and more stroke.

Pete

[heraldcoupe]

Clutch problems like yours are rarely a function of moving insufficient fluid. The slave cylinder will self adjust, most likely is that it's running out of travel before the clutch has full disengaged, ie the piston is bottoming out against the circlip. Anything you do at the master cylinder isn't going to alter that, you'll need to either extend the pushrod into the slave, or modify the slave to allow it to mount further into the bellhousing. Either of these approcahes will effectively alter the range over which the slave operates,

Cheers,
Bill.

[lnpab17]

Thanks gus, thats very helpful. I've only had the car a few weeks. The previous owner had a new clutch complete & a new slave cylinder fitted a few years & 500 miles ago, as he was having problems.

The new master cylinders loon to be good quality & are very reasonably priced, so they'll come in handy in due course. Perhaps I can get a flaring kit & new connector as there is slack on the pipe length.
Cheers, Peter.

[Pete Lewis]

if youre anywhere near bedfordshire we have both nuts and flaring  kit  

there is a full length   flexible you can purchase as another option

often motor factors will flare a new pipe for you with the old used as a master

Peter

[Gt6s]

3756 wrote:

The problem seemed to be that the flare was too large & fouling the threads. I carefully filed it down so that it clears the threads fine on the girling unit, but it still won't fit into the new one.

Sounds to me like an overtightened COPPER pipe, copper pipe suffers badly from overtightening. Get a new pipe made in kunifer at your local motor factors, fittings on girling type cylinders (even repros) should be 3/8 unf.