Master cylinder repair

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360gts
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Master cylinder repair

Post by 360gts »

Anyone been successful in sleeving one of these tandem master cylinders?
Have honed it a few times....still some pitting in the upper areas.......think it is to deep to get out by honing.
Interested in hearing if sleeving is worth trying.
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Craig
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Re: Master cylinder repair

Post by Craig »

Dermott ,

A good customer sent his 59 mini masters down to “ White Post Restoration “ in the US as they do sleeping.
Wasn’t cheap at all though …


https://whitepost.com/brake-sleeving-re ... -services/

Craig
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Re: Master cylinder repair

Post by Craig »

Dermott ,

A good customer sent his 59 mini masters down to “ White Post Restoration “ in the US as they do sleeving
Wasn’t cheap though …


https://whitepost.com/brake-sleeving-re ... -services/

Craig
360gts
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Re: Master cylinder repair

Post by 360gts »

Craig wrote: Thu Apr 28, 2022 2:44 pm Dermott ,

A good customer sent his 59 mini masters down to “ White Post Restoration “ in the US as they do sleeving
Wasn’t cheap though …


https://whitepost.com/brake-sleeving-re ... -services/

Craig

Hi Craig, thanks for the tip.
I can do most of the work myself in my shop.....
Sending one of these to the US would be prohibitive ....exchange rates..postage etc.
MS sell a replacement but it is metric....landed here is around $160.00....unfortunately, would have to rework the lines to change to metric....not a show stopper but a pain.
Cheers
D
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Re: Master cylinder repair

Post by Mudhen »

Related question - apparently that is worth saving...but what about general wheel cylinders and later Mini masters/slaves?

Having just replaced a couple, and looking at the pile I've saved for 30+ years, thinking, 'someday these aren't going to be available anymore and will be needed', are they still worth saving or chuck them in the bin?

It really is becoming obvious to me that my own 'someday' will come before they stop making the hydraulics for our cars.

Thanks
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Peter Laidler
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Re: Master cylinder repair

Post by Peter Laidler »

`I'm not sure that sleeving is the problem that we think it is. Short lengths of honed bore pipe, such as here has been available ever since hydraulic rams were invented and repaired. The hydraulics industry do it day in and day out.

Bore out old to suit, press in/cement in new, drill inlets/outlets and........ Easy to hold and mount in a lathe or drill press too

They've been sleeving shotguns and rifles since the 20's

Worth trying Craig?
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Spider
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Re: Master cylinder repair

Post by Spider »

Boring and fitting the sleeve DIY isn't too difficult if you've suitable machinery, but after drilling the ports, you want to dimple the holes with a ball bearing from the inside so as they don't tear the seals. I read a thread on this process on the forum a few years back.
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Re: Master cylinder repair

Post by andy1071 »

Spider is correct.
The original "cut-off port" (the small hole) was pierced outwards from the cylinder during production, to give a small chamfer to the hole.
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Peter Laidler
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Re: Master cylinder repair

Post by Peter Laidler »

I'm not sure that the holes were very slightly countersunk but in theory, it does make sense. But in practice, maybe. That said, the inlet - from low pressure to high pressure chamber in the clutch master cylinder I used while writing up a clutch hydraulic paper some years ago certainly wasn't countersunk, only highly polished/honed.

Anyone who is re-sleeving master cyls will be able to countersink and tooling is readily available to achieve a countersink within a relatively large bore such as a master cylinder.

Just me thinking on my feet. But as Spider agrees, re-sleeving a bore per-se isn't a difficult engineering problem at all.
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Re: Master cylinder repair

Post by MiNiKiN »

If you honed the bore using flex-hone wouldn't that also chamfer the edges of the cut-off port?!
Yes I am a nerd: I am researching the Austrian Mini-racing scene of the 60s and 70s :ugeek:
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