Bleedin' Bleeping Front Grimeca Caliper?

[comanche91]

Got this one fixed too. I found a used stock Grimeca caliper, swapped them out, bled the brakes and voilà - good firm front brake now w. zero fade. I guess this means I need to find a rebuild kit for the original caliper. Since it wasn't leaking, does anyone know what to look for to repair it? Also, is there a source for a rebuild kit?

Back to my question: Source for a Grimeca caliper rebuild kit for the MZ Rotax 500s? Thanks

[Skorpion]

The Mz caliper is a copy of a BREMBO as fitted to 1980s BMW, MOTO GUZZI, and DUCATI,
so I would think that any of their dealers should be a source of the rebuild kit.

In the UK

MZ SPARES
BURWIN motorcycles.com

http://www.mzspares.com/contact.htm

May also supply to the US?

[comanche91]

The Mz caliper is a copy of a BREMBO as fitted to 1980s BMW, MOTO GUZZI, and DUCATI, so I would think that any of their dealers should be a source of the rebuild kit.
May also supply to the US?

Thanks Skorpion, but which Brembo caliper kit do I look for? Any particular model? I struck on the US sources mentioned previously in this post. Is there a specific diameter Brembo caliper kit?

[Skorpion]

If you check the EBC catalogue for Euro built bikes, around 1980 to 1995 that use the same brake pad FA18.
I just made a quick check,

Motto Guzzi California Mk 11/111 83-90

Ducati 750 sport 88-90

BMW K75 + R 65

Plus many more models, if you have the caliper to hand you should be able to take it to any of the above dealers for a repair kit.

I think its the Brembo P8 caliper, but double check.

Better still if you can get a good used Brembo caliper these are of better quality.

New Caliper inc pads £50 = $80 usd plus shipping.
http://www.motobins.co.uk/displayfinal. ... &title=ALL K\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\\

I hope this helps.

[comanche91]

It helps very much Skorpion - many thanks. Hopefully I can find one on Ebay.

[comanche91]

Just for grins I took apart my old Grimeca caliper in hopes of rebuilding it. In the drawing below, the seals #6 were shot. These look like a seal with a skirt around the outside. But the seals on the other side of the piston #4 (at least as it looks in the parts manual pic) are missing - nada. The only seals in the caliper are the two on the outside of the piston (#6) and of course the o-ring that seals the two caliper halves (#3). Where are the #4 seals? Were there two seal kits for the 41mm Grimeca calipers? I'n confused...........

[Skorpion]

Seals No4 are fitted into the caliper bore and are THE seals just as in any other caliper, No6 are dust seals, most modern calipers don't have them so they need more maintenance.

NO No4 Seals No Brakes!!

[comanche91]

Seals No4 are fitted into the caliper bore and are THE seals just as in any other caliper, No6 are dust seals, most modern calipers don't have them so they need more maintenance. NO No4 Seals No Brakes!!

Okay, found them. They were worn so smooth in the piston cylinder wall I didn't see them. The caliper looked nice and clean inside. I did have brakes with this caliper, but they were spongy. I ordered a new seal kit for a 41mm small body Grimeca caliper for $6.00 (not the same caliper as the MZ Grimeca/Brembo F08 I know) and am hoping they will work. I was unable to find a rebuild kit for the MZ Grimeca caliper, but the pistons measured 41mm.

[comanche91]

I ordered a new seal kit for a 41mm small body Grimeca caliper for $6.00 and am hoping they will work. I was unable to find a rebuild kit for the MZ Grimeca caliper, but the pistons measured 41mm.

The seals from the 41mm small body Grimeca caliper do work fine for the MZ Rotax and ETZ models for rebuilding purposes. You can get them from Vintage Brake in Sonora, CA.

[Beefheartz]

I flush out all the old fluid by attaching a clear pipe to the bleed nipple then just keep pumping until all the fluid passes through the caliper completely and fills with air.Then I refil with fresh fluid with the nipple closed and pump the lever until pressure starts then open the nipple to release any air and bleed till strong.If the brake lever feels spongy then it`s the master cylinder failing and will need a reseal kit and possibly a new return spring.Heat the master cylinder in water when you remove the pressure mechanism for easier removal.
The internal pressure seal will always leak first,then the plunger seal where the lever makes contact goes not long afterwards.When seals start to leak this can apply slight pressure to the floating caliper and the brakes bind slightly,this can also be caused by a dirty fluid build up in the master cylinder and behind the caliper pistons(remove pistons and clean them,heat caliper with hot water to expand the metal so the rubber seals stay in place on the pistons and do not rip off,if they are in good condition you won`t have a problem putting the pistons back after cleaning,but if you do then you need new piston seals)
Always worth greasing the pad pins and sliding parts of the caliper too.

[Louis Mair]

One bike that uses the original Grimeca brake (and switches) is the military Hardly Dangerous Rotax 350.
You should be able to find cheaper options!
Louis

[DAVID THOMPSON]

in the usa its a mt500 and parts for it are harder to get than for the mz bikes

most Harley riders do not know it was ever made
dave