Jim / Scot -
You don't want to hone the aluminum bore, because the cylinder bore is
specially treated at the factory to resist wear. Honing the bore will
remove this hardened treatment and ruin the master cylinder.
Aluminum when it is untreated will wear out quickly... that's why
using rebuild kits on these aluminum master cylinders don't work long
term the majority of the time. If the hardened surface of the bore is
damaged or worn in any way, your only option is either to resleeve
with a SS liner or buy a new master cylinder.
Regards,
Alan
'53 BN1 '64 BJ8
On 4/10/05, Bluechipracing <bluechipracing@snet.net> wrote:
> Bob: Why not hone an aluminum bore?
>
> Jim
>
>
> ----- Original Message -----
> From: "Bob Spidell" <bspidell@comcast.net>
> To: <scotyp@comcast.net>; "healey list" <healeys@autox.team.net>
> Sent: Saturday, April 09, 2005 12:11 AM
> Subject: Re: Brake Master Cylinder Leaking
>
> > Hi Scot,
> >
> >
> > You should be able to get to the MC by removing the air cleaners. You're
> > right, there're just two bolts
> > into the firewall, and the two lines. Use a flare nut wrench--the kind
> > with the slot--to undo the pipe fittings
> > if you have one. Remove the rubber boot inside the cockpit and pull the
> > MC out.
> >
> > Disassemble the MC carefully, noting how everything is put together. It's
> > pretty simple, the most
> > complicated piece being the spring loaded "inner" piston that seals the
> > return line to the reservoir.
> > There's also a wavy spring behind the seal. BTW, when this little seal
> > fails you lose all pedal
> > immediately.
> >
> > Check out the bore of the MC. It should be mirror-smooth; look for any
> > pitting and stick a finger into
> > the bore and feel for any irregularities. If there is any pitting or
> > scoring the bore will have to be sleeved
> > or the MC replaced. I believe the MC in my car is aluminum, but I bought
> > a new one that is steel.
> > DO NOT attempt to hone an aluminum cylinder bore. Also check the
> > condition of the threads and
> > the mating surface for pipe flares ... any gouges or nicks where the pipe
> > beds in and you probably
> > won't be able to get a good seal.
> >
> > Rebuild kits run about $20, a re-sleeve will run $50-80 depending on who
> > does
> > it and what material is used (usually brass or stainless steel). New MCs
> > run $150, but occasionally
> > one of the Usual Suspects will put them on sale.
> >
> > Re-assembly is the opposite of disassembly ... but cleanliness is
> > essential. Moisten all the innards
> > with your brake fluid of choice--or some of the lube that comes with the
> > rebuild kit--before assembly.
> >
> > BTW, what brake fluid are you using?
> >
> >
> > bs
> > ***************************************************************
> > Bob Spidell San Jose, CA bspidell@comcast.net
> > '67 Austin-Healey 3000 '56 Austin-Healey 100M
> > ***************************************************************
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