[928uk] Clutch master cylinder

Tue Jan 21 20:12:55 UTC 2025

I use AUTODOC for nearly all of my non-928 car parts needs. They do have a bit of a reputation but I have never had a problem with them.

The prices constantly change and I am not sure how their procurement model works , but I had to recently overhaul the BMW Vanos timing kit on my mini and whilst BMW Mini wanted £600 per cam gear, AUTODOC provided a pair for an unbelievable £100 new. 

Delivery charges make it uneconomical for small orders, and delivery times can vary considerably although they do keep me up to date with progress.

> On 21 Jan 2025, at 19:40, kenworthy via 928uk <928uk at lists.928.org.uk> wrote:
> 
> Hi Guys,
> I use Autodoc for orig  spares for my 928, X5 and VW Touran and have found prices very competitive and quick delivery for run of the mill parts.
> Just my 2p worth
> Duncan
> 
> 
>> On 2025-01-21 18:05, jonathanrackowe--- via 928uk wrote:
>> Seems that the Master Cylinder repair kit FTE RK19573 isn’t available
>> in the UK. We maybe need to ask you to pick up a few of them Paul next
>> time you’re visiting the N-Ring!
>> Curiously, there is no sign of the rubber spacer “bung” between spring
>> and star washer in the photo of a new disassembled clutch master cyl
>> shown in this rennlist thread
>> https://rennlist.com/forums/928-forum/1114686-rebuild-clutch-master-cylinder-in-the-car.html
>> The only reasons I can see for it are: a) perhaps to stop any
>> possibility of the spring coils getting caught up on the star washer –
>> although that seems pretty unlikely; b) to keep the spring end
>> properly centred.
>> Best regards,
>> Jonathan
>> 1991 928 GT Amethyst Metallic
>> From: Paul R Smith <smiffypr at gmail.com>
>> Sent: 21 January 2025 13:28
>> To: Paul <ukkid35 at gmail.com>; Jon Holdsworth <jon928se at gmail.com>
>> Cc: 928 List <928uk at lists.928.org.uk>; Jonathan Rackowe <jonathan at netvue.co.uk>
>> Subject: Re: [928uk] Clutch master cylinder
>> Nice picture (saved for future reference).
>> Could you see what the "bung" is there for?
>> My '80 one (fixed pre digital cameras) had a one-way valve inside the
>> piston, which involved a small rubber disk, but I can't remember how
>> the piston came apart to access that.
>> Smiffy
>> On 21/01/2025 12:05, Paul wrote:
>> I had to do this a few months ago in between track days at the Ring
>> https://thumbsnap.com/i/MES6LMuz.jpg
>> I used the kit from PartWorks.de on the right hand side of this photo
>> https://thumbsnap.com/i/ouDZeMta.jpg
>> About 12/15 years ago I fitted new seals, but I put the rubber bung on
>> the left on the wrong way round
>> https://thumbsnap.com/i/ZJhMFSGK.jpg
>> So when I took it is apart the bung had split
>> https://thumbsnap.com/i/pMfzS6j9.jpg
>> This is the correct way round
>> https://thumbsnap.com/i/iHFFDXrU.jpg
>> There was a massive rainstorm that started just before I finished the
>> job, which was far from ideal
>> However with the new seals I was able to thoroughly enjoy the second
>> day on track
>> https://thumbsnap.com/i/wG1zBVAp.jpg
>> https://youtu.be/K4y0d98Vzks
>> Paul
>> 87 S4 Manual
>> On Tue, 21 Jan 2025 at 11:41, Jonathan Rackowe via 928uk
>> <928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> > wrote:
>> I second that. Replacing the master cylinder is an unnecessary pain when
>> you can replace its seals without removing the master cylinder and the
>> associated hoses. Seals are the only parts that wear/fail unless you allow
>> water into your brake and clutch fluid.
>> Best regards,
>> Jonathan
>> 1991 928 GT Amethyst Metallic
>>> On Tue, 21 Jan 2025, 10:26 am Paul R Smith via 928uk, <
>>> 928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> > wrote:
>>> Replacing the master cylinder internals can be done from INSIDE THE
>>> CABIN, so you don't have the difficulties removing and refitting the
>>> casting from inside the engine bay.
>>> I got a seal set (for my '80) many years ago. It was trivial to fit (as
>>> long as you are flexible enough to get your head in the foot well), but
>>> I believe there are variations in seal/piston design even with the same
>>> porsche part number m/c, so you would probably have to take out your
>>> piston and measure the seal(s) before ordering to be sure.
>>> It turned out that my problem was not with the m/c anyway. The bellows
>>> on the slave were shredded (perished and crumbling), allowing the
>>> activating rod to vibrate and slowly push the slave piston into it's
>>> bore, and in mine there was no spring to resist that.
>>> Smiffy
>>>> On 21/01/2025 05:17, Simon Crowe via 928uk wrote:
>>> Reading through this topic, it’s great news that the 927 and 928 castings
>>> are the same . I’ve often wondered this but went with the significantly
>>> more expensive 927 M/C a while back.
>>> Replacing the M/c is such a b***h of a job I would recommend only
>>> replacing with new , even if seals are available. I think I read a long
>>> time back somewhere that a M/c kit is available and can be fitted with the
>>> casting in place, but having replaced a M/c it’s not a job I would want to
>>> regularly do.
>>> > On 20 Jan 2025, at 22:46, jonathanrackowe--- via 928uk<
>>> 928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> >  wrote:
>>> >
>>> > Perhaps it depends on having the right size seal. I rebuilt the clutch
>>> slave cylinder for my GT in 2022 and fitting the replacement seal to the
>>> piston was no big deal, but getting hold of that seal was a nightmare as
>>> Porsche only supply a rebuild kit with a seal for the slave cylinders
>>> fitted up to 1989 model year.
>>> >
>>> > Best regards,
>>> > Jonathan
>>> >
>>> > 1991 928 GT Amethyst Metallic
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > From:jon928se at gmail.com <mailto:From%3Ajon928se at gmail.com>   <jon928se at gmail.com <mailto:jon928se at gmail.com> >
>>> > Sent: 20 January 2025 21:51
>>> > To:jonathan at rackowe.net <mailto:To%3Ajonathan at rackowe.net> ; 'Ben Hodges'<benhodges1975 at gmail.com <mailto:benhodges1975 at gmail.com> >
>>> > Cc: 'Mike Miller'<auskartdyno at gmail.com <mailto:auskartdyno at gmail.com> >; '928 Org'<
>>> 928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> >
>>> > Subject: RE: [928uk] Clutch master cylinder
>>> >
>>> >
>>> >
>>> > Hi Jonathan
>>> >
>>> >
>>> >
>>> > Yes I did mean SC. I don’t think rebuild kits are available for the MC
>>> but if they were they would probably be equally difficult to fit.
>>> >
>>> >
>>> >
>>> > Regards
>>> >
>>> >
>>> >
>>> > Jon
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > From: Jonathan Rackowe <jonathanrackowe at gmail.com <mailto:jonathanrackowe at gmail.com>   <mailto:
>>> jonathanrackowe at gmail.com <mailto:jonathanrackowe at gmail.com> >  >
>>> > Sent: 20 January 2025 23:08
>>> > To: Ben Hodges <benhodges1975 at gmail.com <mailto:benhodges1975 at gmail.com>   <mailto:benhodges1975 at gmail.com <mailto:benhodges1975 at gmail.com> >
>>> >
>>> > Cc: Jon Holdsworth <jon928se at gmail.com <mailto:jon928se at gmail.com>   <mailto:jon928se at gmail.com <mailto:jon928se at gmail.com> >  >;
>>> Jonathan Rackowe <jonathan at rackowe.net <mailto:jonathan at rackowe.net>   <mailto:jonathan at rackowe.net <mailto:jonathan at rackowe.net> >  >;
>>> Mike Miller <auskartdyno at gmail.com <mailto:auskartdyno at gmail.com>   <mailto:auskartdyno at gmail.com <mailto:auskartdyno at gmail.com> >  >;
>>> 928 Org <928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk>   <mailto:928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> >  >
>>> > Subject: Re: [928uk] Clutch master cylinder
>>> >
>>> >
>>> >
>>> > Hi Jon, you wrote about "the rebuild kit for the slave" cyl. Was that a
>>> typo? Did you mean the master cylinder or slave cylinder?
>>> >
>>> >
>>> >
>>> > Best regards
>>> >
>>> > Jonathan
>>> >
>>> >
>>> >
>>> > 1991 928 GT Amethyst Metallic
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> >
>>> > On Mon, 20 Jan 2025, 9:06 am Ben Hodges, <benhodges1975 at gmail.com
>>> <mailto:benhodges1975 at gmail.com <mailto:benhodges1975 at gmail.com> >  > wrote:
>>> >
>>> > Thanks Jon!
>>> >
>>> >
>>> >
>>> > On Mon, 20 Jan 2025 at 08:35, <jon928se at gmail.com <mailto:jon928se at gmail.com>   <mailto:
>>> jon928se at gmail.com <mailto:jon928se at gmail.com> >  > wrote:
>>> >
>>> > I can't see what the difference is between LHD and RHD master cylinders,
>>> the pressure line to the slave comes out of the end of the master (remote
>>> from the pedal) on both and the LHD (928 part number, I have two waiting to
>>> be fitted) has the supply (infamous blue hose) hose connection pointing to
>>> the front of the car. From memory so does the RHD master supply connection.
>>> >
>>> > The only difference I know of is that the push rod connection to the
>>> pedal is a ball joint on RHD cars (M8 thread ball joint readily available
>>> from non Porsche sources John Speake used to sell them) and is a rose joint
>>> type joint on LHD cars because the master lines up better with the pin (not
>>> ball) on the pedal. I presume that the rose joint fitting isn’t M8. If this
>>> assumption isn't correct this isn't a show stopper as you can reuse the
>>> original pushrod.
>>> >
>>> > The rebuild kit for the slave is a complete bastard to fit (primarily
>>> the pressure seal) and needs to be warmed up in boiling water to make the
>>> seal flexible enough to stretch over the piston.
>>> >
>>> > Jon
>>> >
>>> >
>>> >
>>> > -----Original Message-----
>>> > From: 928uk <928uk-bounces at lists.928.org.uk <mailto:928uk-bounces at lists.928.org.uk>   <mailto:
>>> 928uk-bounces at lists.928.org.uk <mailto:928uk-bounces at lists.928.org.uk> >  > On Behalf Of Jonathan Rackowe via 928uk
>>> > Sent: 20 January 2025 11:04
>>> > To: Ben Hodges <benhodges1975 at gmail.com <mailto:benhodges1975 at gmail.com>   <mailto:benhodges1975 at gmail.com <mailto:benhodges1975 at gmail.com> >
>>> >
>>> > Cc: Jonathan Rackowe <jonathanrackowe at gmail.com <mailto:jonathanrackowe at gmail.com>   <mailto:
>>> jonathanrackowe at gmail.com <mailto:jonathanrackowe at gmail.com> >  >; Mike Miller <auskartdyno at gmail.com <mailto:auskartdyno at gmail.com>
>>> <mailto:auskartdyno at gmail.com <mailto:auskartdyno at gmail.com> >  >; 928 Org <928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk>
>>> <mailto:928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> >  >
>>> > Subject: Re: [928uk] Clutch master cylinder
>>> >
>>> > Hi Ben,
>>> >
>>> > Had you already considered new seals?
>>> >
>>> > Why do you need to replace the m/c?
>>> >
>>> > I would consider a sleeved rhd one nearer to stock than a lhd one with
>>> weird hose routing and lengths.
>>> >
>>> > If you do replace your m/c please sell one of us the old one to
>>> recondition.
>>> >
>>> > Have you tried Douglas Valley Breakers for a rhd m/c ?
>>> >
>>> > Best regards,
>>> > Jonathan
>>> >
>>> > 1991 928 GT Amethyst Metallic
>>> >
>>> >
>>> >> On Sun, 19 Jan 2025, 11:10 pm Ben Hodges via 928uk, <
>>> 928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk>   <mailto:928uk at lists.928.org.uk <mailto:928uk at lists.928.org.uk> >  >
>>> >> wrote:
>>> >>
>>> >> Thanks Mike
>>> >>
>>> >> I’m converting my auto to a manual so want to keep things stock for
>>> >> now to minimise the variables!
>>> >>
>>> >> Discussing it with a mate earlier he remembered when he put a new one
>>> >> into his GT it came with two rods - one being longer than the other.
>>> >> I’m going to purchase the 928.xx LHD one and swap the rods over if it
>>> >> is a different length.
>>> >>
>>> >> Cheers
>>> >> Ben
>>> >>
>>> >>> On Sun, 19 Jan 2025 at 20:50, Mike Miller <auskartdyno at gmail.com <mailto:auskartdyno at gmail.com>
>>> <mailto:auskartdyno at gmail.com <mailto:auskartdyno at gmail.com> >  > wrote:
>>> >>>
>>> >>> I had mine stainless steel sleeved and reduces 1 size in diameter to
>>> >>> give quicker clutch action. Little adjustment on the assist spearing
>>> >>> and pedal effort quite acceptable even for an octanagerian.
>>> >>> Mike Miller Brisbane 82s 5 sod
>>> >>>