19 replies to this topic

[macfoot]

Hi how hard is it to fit a Brake Caliper Repair Kit to a Caliper ?
by that i mean the seals and pistons and would you have to split them to do this or can you do it with out spliting the caliper ???

[taffy1967]

I believe you shouldn't split the calliper as you could render it scrap or at least cause bigger problems?

Edited by taffy1967, 14 December 2008 - 07:21 PM.

[macfoot]

thanks for that

[mini.rich]

Re-sealing them is a relatively easy process, the hardest part is getting the piston out of the smaller, outer half, depending on what the condition is like. They will require spliting to re seal them.
Spliting them will cause no harm, there is a seal between the 2 halves which should be replaced, make sure its a proper part and not just an o ring as it is made of a special rubber which is resistent to heat and brake fluid.
It is a good idea to replace the caliper bolts aswell.

[macfoot]

ok thanks for you help

[nicksuth]

You don't need to split them to change the piston seals, however, you may need to replace the pistons if they are badly corroded, pitted or scored? If you take the caliper off the hub, you can use the hydraulic pressure of the brake line to pump out the pistons using a carefully placed bit of wood and working each one a bit at a time until there both nearly out, you should then be able to work them out the last few mm by hand? You will also need some rag (to soak up any fluid) and a brake pipe clamp to nip the flexible pipe when you have the first piston out.

If they've been on a long time I would plan for worse case and have new pistons (stainless steel type) as well as the seal kit?

[macfoot]

thanks for all you help

[rozzer1275]

to get the caliper pistons out remove pads then put some spacers in there place 5mm or so wide (side of a spanner etc) cover caliper with rag just in case the piston comes completely out) then press brake peddle.

the only hard bit if i remember is putting the outer seal metal retainer ring in (i think there is a tool for it somewhere)

As already said any rust on the sides of the pistons and they will get stuck in the caliper.

[Noah 4321]

When puting the o rings in the caliper which way round do they go or does it not matter thanks

[dklawson]

When puting the o rings in the caliper which way round do they go or does it not matter thanks

 

Strictly speaking, the calipers do not use any o-rings.  There are rectangular cross-section rubber seals and it does not matter which way they are installed.  However, make sure the ring glands in the caliper where these sit are perfectly clean and free of rust and debris.  When fitting the seals, lubricate them with brake seal grease or fresh brake fluid.

[Spider]

I always split the calipers, I just find it easier to clean them, inspect them and get the retaining ring for the wiper in.

 

90 times out 100 I've found the bridge seal can be cleaned and re-used, it's only when they have become contaminated that they need replacing, though they are not at all expensive when you can track them down.

 

Probably the hardest / trickiest part of the job is getting the retaining rings for the wiper seals back in.

 

I also use rubber grease on the seals before fitting the pistons back in, though you can use fresh brake fluid too, I just really hate the feel of that stuff on my fingers and I usually paint the calipers, so I'd rather fluid didn't end up on them.

[cal844]

Why mess around with brake components?!! Buy remanufactured calipers this way you know its right!

[dklawson]

Why mess around with brake components?!! Buy remanufactured calipers this way you know its right!

 

I can only speak for myself so my comments will not be applicable to everyone and their particular situation.

1. Over here, there are only a handful of Mini specialists in the whole country from whom you could buy parts.  New 4-pot pairs are upwards of $1000, Cooper-S style 7.5" calipers run about $300 for OEM, $200 for aftermarket (each).  These vendors do not sell rebuilt (not that I've seen anyway) so you would have to have your calipers rebuilt locally.  Rebuilding and repairing brake parts is not inexpensive because the shop doing the work is taking on a large liability.
2. If you are not buying new, you are assuming the rebuilder did a better job than you can do.  If you rebuild calipers yourself, you know exactly what was done and presumably... since it is your car... you won't be taking shortcuts.

As Spider said, the most difficult part of rebuilding a caliper is getting the dust seal retainer installed.

[Spider]

Why mess around with brake components?!! Buy remanufactured calipers this way you know its right!

 

Yes, I do tend to agree, especially at these prices;-

 

http://www.bmcpartsi...collections/all

[cal844]

Why mess around with brake components?!! Buy remanufactured calipers this way you know its right!

 
Yes, I do tend to agree, especially at these prices;-
 
http://www.bmcpartsi...collections/all

Ouch!