12 replies to this topic

[exscousedave]

Hi,

The seal on one of the calipers on my daughters C reg (84) mini has blown. There are two seals per side of the caliper. HBOL indicates that there is one seal plus a dust cover - mini sport have kits that seem to have two seals and another bit - presumably a dust seal.

I can't find a detail of how the dust seals fit (also there don't appear to be dust seals on our set up) - does any one have anything on this. Is therea specific part number I shold be going for???

The car was originally a 998 Mayfair.

Cheers

Dave

[pikey7]

the "other bit" will be a retaining ring for the outer seal.

just checkon the usual spares sites (minispares, minisport, DSN etc) for 8.4" caliper seals. IIRC, around £7 a caliper.

fitment is quite simple. Pop the piston out, lever out the retaining ring and get rid of the two seals. then clean the bore, fit the inner seal, lube the piston and the bore with fresh fluid, fit the dust seal and retaining ring to the piston, push it home, and the use some form of clamp and big washer to clamp the retaining ring home. If in any doubt about the piston, replace that too.

[exscousedave]

Thanks,

Got a kit from the local motor factors and realised that I hadn't seen the retaining ring under all the gunge on the caliper.

Took everything apart, gave it a good clean and fitted the new seals etc. Tried putting the piston back in with a push - nothing, tried a bigger push still nothing. This didn't seem right - basically can't fit the piston back in with a push - I need to put it into a vice to sort it and that just don't seem right to me.

I'll be having a chat with the folks at Minisport / minispares etc. and see what they say.


Does any body know of a decent motor factors in the Derby area?

Cheers


Dave

[pikey7]

ah. you put the dust seal in the caliper rather than on the piston, then in the caliper? It does get tricky the other way as it tends to push the dust seal into the caliper, or, as you found out, prevent you from pushing the piston home.

[exscousedave]

..no!!!

I put the main seal in, tried to fit the piston which would have been followed by the seal had the piston gone in!

[pikey7]

oops! doesn't sound good then! did it fit without a seal at all?

[exscousedave]

Hi,

The pistons fit in the bores OK. Having tried to fit the pistons using a bit more leverage, the pistons fit. I really didn't like fitting the piston with so much force so I took it apart the net result is the lip of the seal is cut off all the way round leaving a very thin circle of seal within the piston and damaging the seal remaining in the grove.

I recon that the 'Moprod' seals are just poor pattern versions and so need to get some from someone a bit more reliable - hence mini sport / mini spares etc.

Cheers

Dave

[TOMMO0302]

I just replaced mine and they were tight, i thought this was the idea.....did you remove all of the aforementioned crud from in around the top of the bore and give it a good clean up?

[exscousedave]

Hi,

All crud clean and shiney before the re-fit - carb cleaner seemed to losen the bulk of the cr@p etc.


I agree that the piston should be a tight fit but I think that these are too tight - I'm fitting the piston square to the bore with plenty of brake fluid to act as a lube - but it just is taking too much combined pressure to fit them unless vice like pressure is what HBOL refers to a pushing the piston into the bore!!


Dave

[pikey7]

assuming you had the right seal in the right slot, then it does tend to sound like the seals you got were, as you say, bad pattern parts.

Certainly when I rebuilt my metty ones, they pushed in nicely, and just neede the clamp to push home the retaining ring on the dust seal.

[exscousedave]

Yeah, looked to make sure the seals were not in the wrong grooves but seals are different thickness and so can only go in one way.

I'll get some proper ones - see how they fit and let you know!!

Dave

[supermotolee]

i got mine from mosses they were very a reasonable price fitted well and gave me no problems ...

[exscousedave]

Success

Got some seals from Minispares and they fitted up a treat.

The material from the problem seals seem to be harder than the Minispares and they also seemed slightly larger so I suppose they combine to make the problem.

lessons to be learnt here...