ausmini
https://www.ausmini.com/forums/

Clutch slave cylinder- cup spreader
https://www.ausmini.com/forums/viewtopic.php?f=2&t=90249		 Page 1 of 3
Author:  drmini in aust [ Sat Aug 15, 2015 10:48 am ]
Post subject:  Clutch slave cylinder- cup spreader
Many folks have trouble with the aftermarket `silver painted' clutch slave cylinders. After some use, or if left standing for weeks, they suck air in past the cup seal and it won't bleed out.
Reason is these cylinders are missing the cup spreader which was in all the genuine cylinders.
p/no is 17H7540, it is now NLA.
I have just made one from HDPE plastic, if anybody wants to make some too, here is a poor sketch.
Sorry, got no CAD on the Macbook and the PC is now dead, RIP.

[edit] If there was enough demand for these I could get them made in quantity on a CNC lathe, it's just not worth moulding them unless making zillions.

Image
Author:  ken@miniauto [ Sat Aug 15, 2015 11:33 am ]
Post subject:  Re: Clutch slave cylinder- cup spreader
Mini Spares UK sell AP clutch slave cylinders (GSY110) that have the correct cup expander
The rubber parts in their cylinders also last longer
AP Cooper S caliper kits (GRK5006) from MS last 12 months of serious racing in Group N before needing replacing. Other ones are lucky to last one race meeting before turning to cardboard!
Author:  drmini in aust [ Sat Aug 15, 2015 12:19 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
The cup seal in these slave cylinders is a common 7/8" one. I have bought good ones in the past from my local brake shop.
I agree many aftermarket seals are rubbish now.
Author:  kiwiinwgtn [ Sat Aug 15, 2015 9:11 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
Hi Kev

Any chance you could post a pic of the finished article

Thanks

Bernard
Author:  drmini in aust [ Sat Aug 15, 2015 9:59 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
I took pics today with my old 4MP Pentax. Both pics look like crap as the part is black and closeup focus is poor, even on macro. I tried my 8MP phone and it was no better.
I will take some more tomorrow with my Fuji, of both the new part and white delrin? original.
Author:  drmini in aust [ Sun Aug 16, 2015 10:50 am ]
Post subject:  Re: Clutch slave cylinder- cup spreader
Here ya go- sorry for the pic quality.
The sketch showed 3 holes, I did 4 because it's easier to do on the mill.
Image
Image
Author:  drmini in aust [ Tue Aug 18, 2015 11:04 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
Well, Laingy came round today and he fitted this new one I made into his aftermarket `silver' clutch slave cylinder.
There is now no lost motion at top of pedal stroke; whereas before, the pedal went down well over an inch before you could feel pressure as the seal lips sealed the bore.

Minispares' genuine slave cylinder (with the original spreader in) may be 2x the price of their cheapo silver one without, but if you need a new cylinder, I'd say it's worth it. :)
Author:  DavidE [ Wed Aug 19, 2015 7:12 am ]
Post subject:  Re: Clutch slave cylinder- cup spreader
drmini in aust wrote:
Well, Laingy came round today and he fitted this new one I made into his aftermarket `silver' clutch slave cylinder.
There is now no lost motion at top of pedal stroke; whereas before, the pedal went down well over an inch before you could feel pressure as the seal lips sealed the bore.

Minispares' genuine slave cylinder (with the original spreader in) may be 2x the price of their cheapo silver one without, but if you need a new cylinder, I'd say it's worth it. :)


Caparo (AP Braking) has a comprehensive catalogue of genuine brake parts for Minis, etc (pages 49, et al). This gives you the part numbers to be looking out for)

Cheers
Author:  drmini in aust [ Thu Aug 20, 2015 9:05 am ]
Post subject:  Re: Clutch slave cylinder- cup spreader
AP only lists the whole slave cylinder, and the seal kit.

I have machined a few spare plastic spreaders now.
I'm not going into quantity production, but if anyone here needs one to improve their aftermarket cylinder, PM me for details. :wink:
Author:  DavidE [ Thu Aug 20, 2015 3:28 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
drmini in aust wrote:
AP only lists the whole slave cylinder, and the seal kit.
<snip>

That doesn't surprise me at all. If you have a genuine slave cylinder it will include the seal spreader, right? If you need to re-seal a genuine slave cylinder, you won't need to replace the seal spreader.
Author:  DavidE [ Sat Aug 22, 2015 8:42 am ]
Post subject:  Re: Clutch slave cylinder- cup spreader
drmini in aust wrote:
Many folks have trouble with the aftermarket `silver painted' clutch slave cylinders. After some use, or if left standing for weeks, they suck air in past the cup seal and it won't bleed out.
Reason is these cylinders are missing the cup spreader which was in all the genuine cylinders.
p/no is 17H7540, it is now NLA.
<snip>


Just done and acquired myself a genuine NOS one offa eBay!

Cheers
Author:  kiwiinwgtn [ Sun Aug 30, 2015 7:22 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
Just acquired a Drmini special. Thanks Kevin
Author:  IndigoBlueCooperS [ Mon Aug 31, 2015 7:57 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
Received a couple today - look good, Thanks Kevin
Author:  simon k [ Sat Mar 19, 2016 10:15 pm ]
Post subject:  Re: Clutch slave cylinder- cup spreader
Gidday Kev

I dug up this post from last year.. is there any reason not to make one of these out of teflon? I have *just* enough left to make one of these for the new slave cylinder I just bought... I've been using a pre-XF Falcon one (smaller bore, more travel), but it's too stiff for the kids to use.

I don't know how I'll go making a tool to machine out the locater groove for the spring (3.7mm x 13mm) - does it need to be there? will it still work if I bore out the centre and make it a neat fit over the spring, maybe even keep the aluminium locator thingy that's in there?

I drew it in solidworks - one of your dimensions didn't work though :? 39.16 degrees instead of 45 - not sure where I've gone wrong

Attachment:
clutch slave spreader.JPG


cheers
Simon



drmini in aust wrote:
Many folks have trouble with the aftermarket `silver painted' clutch slave cylinders. After some use, or if left standing for weeks, they suck air in past the cup seal and it won't bleed out.
Reason is these cylinders are missing the cup spreader which was in all the genuine cylinders.
p/no is 17H7540, it is now NLA.
I have just made one from HDPE plastic, if anybody wants to make some too, here is a poor sketch.
Sorry, got no CAD on the Macbook and the PC is now dead, RIP.

[edit] If there was enough demand for these I could get them made in quantity on a CNC lathe, it's just not worth moulding them unless making zillions.

Image
Author:  drmini in aust [ Sun Mar 20, 2016 4:29 am ]
Post subject:  Re: Clutch slave cylinder- cup spreader
I would use a hard plastic for stability and ease of machining. I use HDPE as I keep it in stock for making wiper escutcheons. Delrin or similar is fine too.
Page 1 of 3 All times are UTC + 10 hours
Powered by phpBB® Forum Software © phpBB Group
http://www.phpbb.com/