Grimeca Rear Caliper rebuild

Maestro, SEI-V
Post Reply
Manda
Posts: 9
Joined: 05 Sep 2017 21:26
Location: Banbury UK

Grimeca Rear Caliper rebuild

Post by Manda »

I have a problem with the Rear caliper on a 500 SEI.
The caliper seized up and needed a rebuild.
Purchased a set of seals from NLM but could not get the pistons as none available and ours were quite badly pitted, beyond a little refacing.
Managed to get a pair of 28mm pistons that were intended for a Brembo caliper via another supplier who stated "morini owners have tried but they have not been too sucessful"
The bike has stood in the garage over winter and have come to it and found the caliper is weeping oil past the seals.
Questions 1
Where to get parts for the Grimeca, does anyone know of substitute parts.
Question 2
Are there any good substitute calipers around, ie brembo etc.

Also trying to get the taper tool to refit the clutch (it was leaking too) tried Ndina, 6 voicemails left, and 5 or so contact forms filled in and not a single response to date.
Where can I get these taper tools from other than having them made.
User avatar
Ming
Posts: 798
Joined: 01 Aug 2014 16:32
Location: France
Location: Central France

Re: Grimeca Rear Caliper rebuild

Post by Ming »

I've bought Grimeca spares from these people before now, might be worth a look. https://www.rgmnorton.co.uk/dept/about-us_d012.htm
harrymuffin
Posts: 292
Joined: 07 Apr 2014 16:06
Location: west midlands

Re: Grimeca Rear Caliper rebuild

Post by harrymuffin »

If you are refering to the tapered sleeves that fit over the splined shafts - the camshaft also has them, I had to make my own for the 500 and the 350. If you cannot get hold of them, then the trick is to rap electical insulating tape round the spline, just covering the first 1/8" to 1/4" of the spline/sharpe edge of shoulder and down onto the plain shaft, lubricated with oil or grease and push the seal in, if you have not removed the clutch cover, then carefully unpeel the tape, which if fitted properly should not be covered by the seal lip. If it is, then after removal check the lip has not reversed itself. Tip; rotate the shaft as you unpeel the tape.
'It must be a .....'
Posts: 365
Joined: 12 Sep 2010 12:25

Re: Grimeca Rear Caliper rebuild

Post by 'It must be a .....' »

I've used the same solution when rebuilding engines, although tapered sleeves would be ideal you don't really need them; build a taper with masking tape and lubricate with oil, then the tape is easily removed afterwards.
MickeyMoto
Posts: 2415
Joined: 22 Nov 2008 17:41
Location: Even further oop North

Re: Grimeca Rear Caliper rebuild

Post by MickeyMoto »

I have found some 28mm pistons for Grimeca. What is the piston depth and seal size? The kit also comes with the o-ring for the caliper.

I am looking for some myself but not got them in bits yet.

If correct, the kits are about £15 per caliper.
User avatar
Daddy Dom
Posts: 512
Joined: 16 Nov 2006 19:48
Location: Auckland, New Zealand

Re: Grimeca Rear Caliper rebuild

Post by Daddy Dom »

Sometimes a more generic search can get results as many of these parts were used on other Italian bikes.

Also trying to get the taper tool to refit the clutch (it was leaking too) tried Ndina, 6 voicemails left, and 5 or so contact forms filled in and not a single response to date.
Where can I get these taper tools from other than having them made.

I'm sorry you're also experiencing this. Ordering something in stock is easy online but anything else is not.
MRC 3082½
simonnorthroad
Posts: 388
Joined: 16 May 2017 10:57
Location: Bath, UK

Re: Grimeca Rear Caliper rebuild

Post by simonnorthroad »

I gave up trying to buy a clutch-lever from Mdina after a couple of emails and sending the requested photo, then getting no response
Manda
Posts: 9
Joined: 05 Sep 2017 21:26
Location: Banbury UK

Re: Grimeca Rear Caliper rebuild

Post by Manda »

I have just been and checked,
The original Piston is not 28mm as I previously stated :oops: should not do these things from memory, now wondering what is 28mm, and no did not fit 28mm pistons in a 38mm hole. :|

The piston is 38mm diameter where it meets the seals and 14mm deep until the step at the top, total depth is 20.12mm

Sorry about the confusion
Post Reply