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Hi,
I've got a few old Jaguar MK2 brake calliper cylinders that need resleeving, I know this can be done professionally but wondered if it is something that I can do myself?
The Jaguar MK2 brake callipers have a removable cylinder on each side and are different to more modern callipers in that the seal fits to the piston and slides in the calliper bore rather than the seal being in the bore and the piston moving against the seal.
I have a lathe with a 4 door chuck on it so boring them out isn't an issue, has anyone done something like this and if so what type of sleeve did you use (I assume stainless but what grade) and how much of an interference fit do you need between the cylinder body and the sleeve? Also is any form of adhesive (loctite?) used to help make sure the sleeve doesn't move.
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Hi, I read on another forum that someone wanted to do it himself but was advised to let the professional outfits do it because it's fraught with hidden pitfalls. It's a thin wall stainless sleeve (don't know the grade) so pressing it in even with a mandrel risks the sleeve folding up. Another potential fail point is if it's not tight enough, hydraulic pressure can creep up between the sleeve and the body of the caliper, although whether a sealant is used or a temperature differential is used I don't know which would be better in that case. Sorry to be negative, but I can see potential pitfalls along the way as well.
Colin
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stealthstylz
Club Retro Rides Member
Posts: 14,835
Club RR Member Number: 174
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If you've got (or can get hold of) a completely knackered caliper i'd be tempted to chop it in section and see what material there is to work with.
A stainless sleeve would be nice, but mild steel lasts a long time and is a lot easier to machine a nice finish onto. I'd see if there is a off the shelf tube size that would work on the O.D with a smaller I.D, bore the caliper out to leave a 2 thou interference fit, press the sleeve in then bore that out to close to the finish size leaving enough to put a fine sanded finish on.
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I think sleeving a master cylinder would be a lot more difficult but I can't see that sleeving these cylinders is particuarlly difficult albeit there is a high degree of accuracy required which might yet prove to be beyond me :-)
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If you've got (or can get hold of) a completely knackered caliper i'd be tempted to chop it in section and see what material there is to work with. A stainless sleeve would be nice, but mild steel lasts a long time and is a lot easier to machine a nice finish onto. I'd see if there is a off the shelf tube size that would work on the O.D with a smaller I.D, bore the caliper out to leave a 2 thou interference fit, press the sleeve in then bore that out to close to the finish size leaving enough to put a fine sanded finish on. Reading about this yesterday it seems that some people use brass or bronze which is presumably easier to machine but no one seemed to be able to offer pros or cons of either. Looking at all three materials there are different grades but its unclear which one I would need.
The cylinders are like this so should be fairly simple to do I would have thought?
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jimi
Club Retro Rides Member
Posts: 1,816 
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A 4 jaw chuck isn't the ideal thing for turning accurate sleeves, a 3 jaw would be better, quicker and easier to set up. Personally for something like that I'd go down the professional route, easier, quicker and possibly cheaper at the end of the day, allowing for possible mistakes in a diy job  also bearing in mind the safety aspect .. |
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Last Edit: Jan 3, 2024 12:40:19 GMT by jimi
Black is not a colour ! .... Its the absence of colour
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A 4 jaw chuck isn't the ideal thing for turning accurate sleeves, a 3 jaw would be better, quicker and easier to set up. Personally for something like that I'd go down the professional route, easier, quicker and possibly cheaper at the end of the day, allowing for possible mistakes in a diy job also bearing in mind the safety aspect .. The shape of the cylinder wouldn't fit in a 3 door chuck unfortunatly as its a rectangle, my thoughts were to buy the tube at the right size (if possible)and bore the cylinder out in the lathe to just undersize (1-2 thou seems to be the recommendation).
Heat the cylinder in the oven, cool the sleeve in the freezer and then put the two together using some red loctite (need to check what is suitable) and then bore the cylinder sleeve in situ to the exact size required.
I was always under the impression that a four door chuck was more accurate than a 3 door as you can set the work up to exactly what it needs to be using a dial gauge whereas a three door always has a slight run out? I appreciate the 3 door is a lot faster and for most jobs the accuracy isn't a problem but in this instance a four door would be the only way to do it with the equipment I have.
I don't actually need to do this for my car as i've already sorted the brakes out but I have a lathe that i've just got working after many years and it seemed like an interesting project to try.
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jimi
Club Retro Rides Member
Posts: 1,816
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I should have been clearer, I was only referring to machining the sleeves as the stock would be round in the first place, obviously for an eccentric shape the 4 jaw is the only real option (other than a faceplate), the accuracy of a 4 jaw is dependant on the person setting the job up, it's not always easy & straightforward.
If I had to do it I'd be looking at using a drill press for the calipers using a standard size of drill and then machine the sleeves to suit. Much easier to set the caliper up on a table than in a chuck.
I.M.O of course and I'm no expert 👍
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Last Edit: Jan 3, 2024 18:13:28 GMT by jimi
Black is not a colour ! .... Its the absence of colour
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pptom
Part of things
Posts: 470
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Far from an eggspurt myself, but with an interference fit isn't it standard practice to leave the ID of the insert oversize and only machine / ream to it's finished size once it's fitted.
The ID will fractionally change pre / post fitting, depending on how much interference there is. A Zeus book / the internet will give you standard interference fits for a given diameter
Edit: sorry, just read that you were planning to bore after fitting
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Last Edit: Jan 3, 2024 19:56:35 GMT by pptom
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Thanks for all the input guys, I might have a go at it over the long winter evenings if I can find a suitable piece of stainless or brass to sleeve it in.
If nothing else it will be an interesting test for the lathe and if I make a mess of it then it doesn't really matter as the calliper cylinders are scrap anyway without being sleeved and I don't need them so would just put them on the shelf as spares.
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jimi
Club Retro Rides Member
Posts: 1,816
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Don't forget to update the thread with any developments 👍
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Last Edit: Jan 3, 2024 23:30:52 GMT by jimi
Black is not a colour ! .... Its the absence of colour
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also bearing in mind the safety aspect ..