Caliper rebuild - grease puzzle

[Oldmogman]

I'm fitting new seals to my Marina calipers using a kit from ESM, which comes with a little tube of grease.

Except I'm not quite sure where to put it, since my Marina manual doesn't mention grease. Obviously, the Marina caliper is fixed so there are no sliders (apart from the pins retaining the pads), so my guess is that it's meant to go under the piston boots to stop any moisture?

Could anyone confirm - or tell me where it should go?

Thx all

[Oldmogman]

Forgot to say, the tube of grease is marked 'grease only for glidebush'.

From what I understand, this is the pin used for sliding/floating calipers - so why would it be included in a kit for a fixed caliper?

[philthehill]

If it is the RED brake grease it is used to lubricate the piston against the piston seals and if it is not you will need some RED grease.
As you quit rightly say there are NO moving parts inside the calliper except for the calliper pistons.
So to sum up the RED grease goes around the piston and piston seal and any excess is put between the piston/piston seal and the outer dirt seal.
Overhauling the Marina callipers is a reasonably easy job but I would advise you not to split the two halves of the calliper body as that can lead to leaks and mis-alignment of the two halves of the clipper body.
I have looked at the ESM web site and the overhaul kit for Marina disc brakes does not include a tube of grease.
I have got Marina disc brakes on my Minor and I have replaced the calliper seals seals several times as a matter of course; not that there has been anything wrong with them but just like to know all is well with them.
You can just use brake fluid instead of the RED grease but I like to have the RED grease as well for a bit more lubrication.
How were the pistons? No pitting I hope because if there is the slightest pitting they will need to be replaced as the pitting can and will eventually cause the seal to leak and possibly fail.
If it is copper grease it goes either side of brake pad anti-squeal plate which is fitted between the calliper piston and brake pad. Make sure that not too much is used as it can get onto the brake pad.
The anti-squeal pad should have an arrow cut into it and that faces the direction of travel of the disc.

[bmcecosse]

As above - get some RED brake grease.. The bolts securing the two halves together are intended to be 'one use only' - so if you split the calipers - make sure you have new seals (sometimes hard to get) and new bolts... Here's the grease.... http://www.ebay.co.uk/itm/18g-Castrol-R ... 1e6d1c5b18

[philthehill]

I have found a new spare set of Marina brake calliper seals supplied by ESM and there is a small tube of grease included and on the front of the tube it states Brake Engineering Service Part SK1. On opening it is found to be a clear silicon type grease.
On the back of the tube it says 'Grease only for glide bushes' plus the same in three other languages.
I do not recognise it for use on a Marina brake set up. It may be a replacement for the RED grease applied to the piston seals/pistons - but I would not use it not knowing its composition. RED grease/copper grease all the time for me.[frame][/frame]

[Oldmogman]

Thanks guys

Yes, I've used the red grease before, which I why I was rather puzzled by the tube of clear gel that came with the kit.

Unfortunately, the top has come off my red brake grease and it's congealed so I need to get some more (yes, could get away with just brake fluid but since the car is often laid up during the worst of winter, I think it's worth adding some extra lube).

Pistons are fine and, no, I won't be splitting the calipers; they're actually relatively new but I notice they were a little sticky when I came to replace the pads.

Now all I need is a helping foot to bleed the brakes when they're rebuilt...

[Oldmogman]

Thanks Philthehill

Snap! That's the tube I've got!

[philthehill]

I agree - lack of use does lead to lazy calliper pistons.
For information:
The original overhaul kits for the Marina are Lucas Girling Pt No: SP26971.

Attached is the instructions for the overhaul of the Marina brake callipers and came with the Lucas Girling overhaul kit.[frame][/frame][frame][/frame][frame][/frame]

[M25VAN]

Now all I need is a helping foot to bleed the brakes when they're rebuilt...

A nicely shaped length of wood that fits between the steering wheel and brake pedal when fully down will allow one man bleeding. Not as good as someone pumping the pedal and that lovely jet of fluid expelled when the nipple is opened but it will stop fluid/air being drawn back into the system. This works for me and got around the problem of air being drawn back in despite using a non return valve on the bleed tube.

[bmcecosse]

Gravity bleeding - works well for me.... Just make sure the caliper bleed nipple is at the top when installed... many a Mini owner has struggled hopelessly with calipers fitted wrong side..and bleed nipples below..... Not me I hasten to add - but it's amazing how often it comes up in Mini forums...

[Oldmogman]

Thanks for the tips and fitting instructions, guys. And especially the part number (my local parts shop had no listings for it)!