I have just overhauled some MG calipers and referring to the workshop
manual came across the following

"Unless it is absolutely unavoidable the caliper should not be separated
into two halves. In the event of separation becoming essential, the
fluid cannel seal, clamping bolts.and lock plates must be renewed when
reassembling. Only bolts supplied by BMC Service Ltd. may be used. On
assembly these must be tightened with a torque wrench set at between
35.5 - 37 lb.ft 4.9-5.1kg m.

Ensure that the caliper faces are clean and that the threaded bolt holes
are thoroughly dry. Make certain that the new fluid channel seal is
correctly located in the recessed face before assembling the caliper
halves."



This is most likely where, in the first paragraph, the "forbidden in the
Haynes manual" comes from.

Secondly the bolts are a extra high tensile and have 6 marks on the head
- not the usual 3 as in high tensile marks - hence the higher torque
settings.

Hi Rob,
did it say anything about the two halves being pressed
together prior to the bolts being torqued up,
I mentioned this a while ago, as I recall reading it somewhere,
Fitzy


"Rob" <mesa (AT) mine (DOT) com> wrote

The main thing is keeping the surfaces clean and getting the fluid seal
fitted correctly. 35-37lb ft is quite low so you need to ensure that the
threads are clean and not binding in any way so you get a correct torque
reading. I would think getting hold of the bolts would be the most
difficult part of the job.

It is quite normal on other cars to split calipers and use a spacer when
converting to ventilated discs, the spacer has a grove for the seals on both
sides and you use 2 sets of seals, the kits come with new bolts as they need
to be longer.



"Rob" <mesa (AT) mine (DOT) com> wrote

Fitzy wrote:

I can't see why the press as the surfaces are flat and for sure its not
going to make any difference. The most difficult bit would be to set the
caliper up squarely under a press so pressure could be applied.

I've always only cleaned the surfaces on a surface plate (or glass) with
400 wet and dry paper then placed the seal into the recess with some
silicon fluid then tightened the bolts up. None have leaked.

The information quoted is not mentioned in the Mini service manual at
all and the calipers are virtually the same.

rm