Grimeca brake caliper piston sizes question.

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Fastmongrel
Posts: 208
Joined: 07 Nov 2022 22:37
Location: Lancashire

Grimeca brake caliper piston sizes question.

Post by Fastmongrel »

I have stripped the front Grimeca caliper on my 81 Strada and it was full of brown sludge probably ancient brake fluid. I want to replace the seals and the pistons.

I have found the correct 41mm seal kit at Mdina but the only pistons I can find are 41 x 18mm ones for a GM1 go cart brake. The pistons that came out of the caliper measure 41 x 15.6 mm and the piston hole in the caliper is 16.6mm deep.

Can anyone point me in the right direction for pistons they seem to be in very short supply.
1981 3 1/2 Strada
Fastmongrel
Posts: 208
Joined: 07 Nov 2022 22:37
Location: Lancashire

Re: Grimeca brake caliper piston sizes question.

Post by Fastmongrel »

After a good soak in brake cleaner the nasty cack on the pistons I thought was corrosion has come off. Must have been more of the ancient brake fluid, the pistons are actually in really good condition and look like brand new. I will just fit the new seals and hope there's no leaks.
1981 3 1/2 Strada
Neadethal
Posts: 51
Joined: 20 Feb 2023 10:21
Location: Oakham

Re: Grimeca brake caliper piston sizes question.

Post by Neadethal »

Great you ended up not needing a solution but i've read and think there is a video that people machine down 18mm pistons to fit from the same kart brake. Hope this helps.
mikebn
Posts: 48
Joined: 18 Mar 2007 10:04
Location: southend essex

Re: Grimeca brake caliper piston sizes question.

Post by mikebn »

i have had made 40 x16 black anodized cliper pistons they are in the latest copy of club mag
Hi i own a 1976 morini 3 1/2 sport wire wheels disc brake front,
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