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 Posted: Sep 19, 2018 10:51AM
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66 Cooper S,

Email me offline and I'll send you pics of my servo rebuild and what I meant by "third bore", the air valve hole that may be only 3/8".  The first two are really the main bore but it's stepped.  I don't recall but was it 5/8" and 1/2"?  Maybe 3/4" and 5/8"...

Although DK Lawson makes a strong case for buying a fresh servo and be done with it...  

 Posted: Sep 19, 2018 03:30AM
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TTF, many years ago I thought I would rebuild my car's servo.  When I took the unit apart I found that both the pushrod and the casting bore were badly pitted.  In the end I sent my car's used parts to John.  ( I hope some parts became donors for a rebuild along the way ).

I bought the reproduction Mk1 servo that was available at the time.  They seem to go in and out of production.  It looks like MS has them at this time for 180 GBP.  They look correct except the outer surface of the casting is smooth aluminum instead of rough cast iron.  I painted the casting on mine black.  A purist looking at my car will recognize that smooth/rough difference but otherwise it looks correct and does the job.

When researching this years ago I found that the Bondali / Benditalia servo used on Alfas appeared to be the same servo.  However, the Italian servo is priced a bit higher than the MS reproduction so there is no cost savings going that route.  See the link below.
https://classicalfa.com/products.php?product=BR100R-BONALDI-%7B47%7D-BENDITALIA-STYLE-BRAKE-SERVO

Doug L.
 Posted: Sep 17, 2018 07:37PM
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Velopavkrot-Where is the third bore??

MiniBill- I know there are other servers that will work. I would like to stick with my mark one server or as I’m doing now running without. This is not a Concours restoration As I think the only thing left original on my car is the glass.

thanks everyone for your restoration places

And John thank you very much for your help.

 Posted: Sep 17, 2018 05:44PM
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By "servo" I assume you are discussing the vacuum brake booster unit.   Are there boosters from other makes of cars that will fit the Mini Cooper?   Alternate parts choices are good if you are doing a resto that is not _concours_.

 Posted: Sep 17, 2018 03:56AM
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CA
Or if in Canada, John Stuart Hydraulics in Stoney Creek, Ontario (Hamilton)

Real pros

 Big AL

[email protected]

Niagara Ontario Canada

 Posted: Sep 16, 2018 08:45PM
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 Thanks guys. Looks like I’m gonna be taking some time soon to take this apart, again. Really the worst part is it’s gonna be messy because it leaked again. But it’s sitting in front of my chair where I see it every day. I guess it’s time to get it done. Cheers

 Posted: Sep 16, 2018 01:38PM
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Or check out White Post Restorations for hydraulics rebuilding.

 Posted: Sep 16, 2018 01:11PM
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It's rare to find an early Lockheed servo with no pitting in the bores.  If you have good eyes and a flashlight, you'll see.  I had mine resleeved and once back together it functioned like new with no leaks.  As you know there are three bores to sleeve, the stepped main bore and also the little side bore for the air valve. 
One guy in CA uses stainless sleeves but he was a bit frustrating to work with, frankly.  Another option are these guys:
www.applehydraulics.com  Check with them but I recall they press in brass sleeves?  

 Posted: Sep 16, 2018 11:21AM
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Quote:
Originally Posted by tothefloor
Thanks John. I’ll need to look at this again tomorrow but my only question is where you said to immerse the parts in brake fluid can I use silicone instead?? I assume that’s what I do. 
When that was written the choice was DOT3 - I can't advise on silicone.

 Posted: Sep 15, 2018 09:38PM
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Thanks John. I’ll need to look at this again tomorrow but my only question is where you said to immerse the parts in brake fluid can I use silicone instead?? I assume that’s what I do. 

 Posted: Sep 15, 2018 07:58PM
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Quote:
Originally Posted by tothefloor
 On the Mk1 servo, It does not appear that any of the rubber parts went bad  including the diaphragm. Well I changed all the rubber parts.  So does that leave the bore??  Is there an easy way to see inside, poor eyes. I’m not doing anything yet just looking at options. Thanks
TTF - Steve I have only cleaned the parts, purchased the rebuild kit, and in one of the last rebuilds I did quite a few years ago I bought a new push-rod from Nick in Sheffield (he had some new ones made) I also had the vacuum shell, end cover and clamping ring chrome plated. Other than looking pretty it had no effect on the servo operation.  I used a bore cleaning kit (as used on pistol and rifle bores) when cleaning the bore in the slave cylinder body.

     "When stripping and servicing your Servo, it is handy to have a component drawing to relate where things fit. The determining factor of whether your Servo is serviceable or not, will mainly depend on the condition of the internal hydraulic bore.  It is best to clean with white spirit or petrol and inspect whilst holding up to the light.  Any severe pitting of the bore where the seals fit is bad news. Also any pitting of the push rod where it travels through  the cup seal requires a replacement rod.  Carefully inspect the air control valve diaphragm for holes. If you are satisfied that the Servo is serviceable, then the service kit is available from most Mini parts suppliers and Motor Factors who specialize in brakes.  When rebuilding, always immerse the seals in brake fluid before fitting.  I try to avoid rubber grease because it can cause later problems when bleeding the system.  Follow any instructions in the kit or in a workshop manual if you are unsure." - Gary Corpe from a December 2000 MCR magazine

     If you want me to scan an send you more info let me know - email in profile.
John

 Posted: Sep 15, 2018 06:29PM
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 On the Mk1 servo, It does not appear that any of the rubber parts went bad  including the diaphragm. Well I changed all the rubber parts.  So does that leave the bore??  Is there an easy way to see inside, poor eyes. I’m not doing anything yet just looking at options. Thanks