Grimeca hydraulics

Maestro, SEI-V
Seagreen
Posts: 86
Joined: 18 Jan 2018 21:18
Location: Cheltenham UK
Location: Cheltenham, Glos

Grimeca hydraulics

Post by Seagreen »

Morini rear master cylinder_IMG_2220.jpg
Morini rear master cylinder_IMG_2220.jpg (182.04 KiB) Viewed 8577 times
Grimeca rear master cylinder for 500 Morini
Grimeca rear master cylinder for 500 Morini
Morini rear master cylinder_IMG_2219.jpg (161.4 KiB) Viewed 8577 times
Hi,
I am in the process of renewing the seals, boots etc on my 1984 Morini 500 Sport and would appreciate some advice.
1. In the mouth of the mastercylinder there appears to be a dust seal/boot at the entry to the main bore that is perhaps retained or just sited behind a "washer" - see photos. How do I remove this so that I can replace the seal/boot that seems to be torn and which I suspect will make the insertion of the piston subassy difficult?
2. In order to remove the caliper pistons and their seals, is it best to split the calipers into their respective halves? If so, are there 2 'O' rings that seal the 2 halves? Is there a torque setting for the 2 cap head screws when reassembling the halves?
3. I realise that I should probably have pushed the pistons out with the mastercylinder still connected to the caliper - does anyone have a good method for extracting them by other means?
4. Finally, where is the best place to buy these parts from - Mdina seem to have a very limited set of items on their website. I would have thought that it would be possible to buy a refub kit for both the mastercylinder and the caliper with all seals, boots, 'O' rings, copper washers and springs. Am I living in a dreamworld or have I just not found the right site?
Thanks,
Charles
MickeyMoto
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Re: Grimeca hydraulics

Post by MickeyMoto »

Charles,

Talk to DucrapiPaddy, he did my Grimeca calipers. You can have a conversation about Chinese parts with him! :)

MM
Seagreen
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Joined: 18 Jan 2018 21:18
Location: Cheltenham UK
Location: Cheltenham, Glos

Re: Grimeca hydraulics

Post by Seagreen »

Hi Mike,
Thanks for replying; I had contacted Paddy before my posting on this forum. He referred me to Mdina Italia. As for Chinese copies, never heard of such things :shock:
Adios,
Charles
MickeyMoto
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Re: Grimeca hydraulics

Post by MickeyMoto »

Maybe Paddy was warned off after doing my calipers!
AntietamClassicCycle
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Location: Rohrersville, MD, US
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Re: Grimeca hydraulics

Post by AntietamClassicCycle »

Seagreen wrote: 4. Finally, where is the best place to buy these parts from - Mdina seem to have a very limited set of items on their website. I would have thought that it would be possible to buy a refub kit for both the mastercylinder and the caliper with all seals, boots, 'O' rings, copper washers and springs. Am I living in a dreamworld or have I just not found the right site?
I bought seal kits from this ebay seller for my K2:
https://www.ebay.com/sch/m.html?_ssn=va ... a&_sacat=0
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Ming
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Location: Central France

Re: Grimeca hydraulics

Post by Ming »

Ariete products are fairly easily available this side of the Atlantic, try a search using the reference from above.
Seagreen
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Location: Cheltenham UK
Location: Cheltenham, Glos

Re: Grimeca hydraulics

Post by Seagreen »

Hi Mike, Ming and Antietam,
Sorry to be a bit slow in responding but have had trouble logging in to the web site via my phone over the last couple of days whilst I have been away (some sort of SQL error whatever that means) but thanks for your comments - Mike I think that you must have administered the kiss of death to Paddy, he did not seem to want to know!! I have checked the Antietam site but as it is in US, the costs of shipping to UK will be very high but I have found an Ariete site in Italy, again cost of shipping will add significantly to the cost so I will try to find somewhere in UK. What about the spring for the m/cylinder?
About removing the pistons and cleaning everything, would I be correct in thinking that the calipers will have to be split and if so the 'O' ring seal (2 off I presume) will need replacing. What about the torque required to tighten the 2 halves together?
Adios,
Charles
huub
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Joined: 24 Jul 2006 15:11

Re: Grimeca hydraulics

Post by huub »

i did rebuild the calipers on my morini using plain o-rings ,
you need EPDM o-rings for use with brake fluid.
i did not have to rebuild the master cylinder , cant help you there.
Seagreen
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Joined: 18 Jan 2018 21:18
Location: Cheltenham UK
Location: Cheltenham, Glos

Re: Grimeca hydraulics

Post by Seagreen »

Thanks Huub, can I ask where did you get your piston seals and dust covers from?
Adios,
Charles
huub
Posts: 194
Joined: 24 Jul 2006 15:11

Re: Grimeca hydraulics

Post by huub »

Thanks Huub, can I ask where did you get your piston seals and dust covers from?
Hi charles,

My 1976 morini did not have dust covers fitted not sure if they were fitted originally.
i just changed the seals with EPDM O-rings from my local bearing/industrial supply shop,
total cost was less than a euro..
the pistons were damaged too , i ended up making a set of stainless ones
Seagreen
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Location: Cheltenham UK
Location: Cheltenham, Glos

Re: Grimeca hydraulics

Post by Seagreen »

Hi Huub,
Thanks for the info. I have bought some seals + O ring from Mdina Italia. They are similar but not identical so am wondering whether the old seals were incorrect - could they have been Brembo parts?
As for the dust seals, well those that I bought are significantly different to those that I took off so I am a bit confused.
Adios,
Charles
norbert
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Re: Grimeca hydraulics

Post by norbert »

One thing are the dust covers that are not that imortant another thing are the seals for the pistons (plus the O-ring between the two parts ofthe caliper)!

For Grimeca, Brembo, Lockheed ... stuff contact Jörg Bohnenstiel "Bomoto" bomoto@t-online.de I guess he can help you :wink:
https://www.bomoto.de/joomla/

norbert
EVguru
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Re: Grimeca hydraulics

Post by EVguru »

Using O-rings as caliper piston seals is likely to result in brake drag.

The shape of the ring groove, along with the rectangular section seal, retract the piston a small amount.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
norbert
Posts: 750
Joined: 15 May 2007 15:15
Location: Lübeck/Germany

Re: Grimeca hydraulics

Post by norbert »

That´s absolutely right. The seals for the pistons have a rectangular shape. The little one between the two halfs (missing on the foto) maybe have a round shape, I don´t remember it well. Anyhow they have to be of a brake fluid resistant mterial.
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EVguru
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Re: Grimeca hydraulics

Post by EVguru »

Seal kits for 41mm Grimeca calipers are available from several sources. There is a version used to replace the AP Lockheed caliper on Triumphs and Nortons and the seals are the same as the 1010 and 1025s.
Paul Compton
http://www.morini-mania.co.uk
http://www.youtube.com/user/EVguru
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