Cooper S servo

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Rev 1.2 (16.09.20)
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Cooper S servo

Post by ntonio »

Does anybody know where to find a MK1 Cooper servo or a website where buy a reliable repro one at good price?

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Re: Cooper S servo

Post by iain1967s » ... rake-servo

That’s the nearest repro I’ve seen.
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Peter Laidler
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Re: Cooper S servo

Post by Peter Laidler »

Did I hear that the overhaul kits are interchangeable too?
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Re: Cooper S servo

Post by Andrew1967 »

Not sure of the difference to braking effect in practice but remember that not all Type 5 1/2’s are equal ….

Different bore sizes are indicated by machined grooves on nose of body. S servos have no groove.

What bore size are the repro ones ?
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Re: Cooper S servo

Post by iain1967s »

I have one on order, so I’ll report back when I fit it in Spring.
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Re: Cooper S servo

Post by LuisM »

Hello Antonio ,

I have a genuine mk1 servo for sale , needs a full rebuild though.
Please PM me if you have any interest .

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Re: Cooper S servo

Post by TECH396 »

I looked into those Alfa ones some time ago.
I was informed that the Pressure Ratio was higher on the Alfa one, due to the larger Diaphragm size.
The bore size was 5/8". Here's the reply I got from them.

[quote....The Bendix servos are similar to Mini ones but the pressure ratio is higher on the Alfa one.
BR006 diaphragm for the BR100 servo is 6.85” o/d. the seal that goes against the piston is 5/8”....quote]
Paul H.
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Nick W
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Re: Cooper S servo

Post by Nick W »

I used to use the alfa one one my old green S, it worked perfectly fine.
The mini spares one, is a more accurate looking one, but don't think they make it any more due to some having issues. Although the 2 that I fitted worked fine.
Up North in Sheffield
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Re: Cooper S servo

Post by spoon.450 »

I once had an Alfa servo but was put off slightly as it had metric ( M10 x 1 ) threads for the brake pipe fittings, rather than the 3/8 UNF as Mini.
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Re: Cooper S servo

Post by jaknight »

Nick W
I purchased a Mini Spares reproduction brake servo a few months back but not installed.

Do you know what issues those servos may have ?? That concerns me as to the safety depending upon issues.


Jim K
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