Starting cafe racer restoration Commando 850 MK3 from Spain

baz said:
Is the casting of the caliper machines to take a banjo ?
Click to expand...

The two calipers on my Mk3 are not machined but wouldn't take much to smooth the surface down if done with care.
 
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L.A.B. said:
The two calipers on my Mk3 are not machined but wouldn't take much to smooth the surface down if done with care.
Click to expand...
For some reason RGM sent me a braded hose with a flange type union on the end instead of the taper seat type. I was pretty surprised they would do that, as like you mentioned the surface is not machined and normally has the casting joint running right across it. I was under time pressure to take the bike for it's MFK (MOT) test so I elected to use it. I put a foam earplug in the hole and carefully filed the surface flat, then used a copper washer to seal it. By the time I got to the testing centre the bloody thing has wept enough for the tester to see and failed it. :mad:
 
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cliffa said:
For some reason RGM sent me a braded hose with a flange type union on the end instead of the taper seat type.
Click to expand...
Like this? What fitting did it have at the other end?
www.rgmnorton.co.uk

FRONT STAINLESS BRAIDED BRAKE HOSE COMPLETE WITH STAINLESS FITTINGS

FRONT RGM NORTON STAINLESS BRAIDED BRAKE HOSE
www.rgmnorton.co.uk

Did you specify a master cylinder to caliper hose or master cylinder to bracket (and Bundy pipe) because the short fitting in RGM's picture would normally be attached to the master cylinder (that is machined flat) with a copper washer and the longer (bulkhead) fitting at the lower end attached to the bracket/Bundy pipe?

RGM: "STATE IF YOU ARE GOING FROM MASTER CYLINDER TO THE CALIPER OR MASTER CYLINDER TO METAL BRACKET."
Click to expand...
 
Good to know RGM can supply a tailored made stainless steel hose. I will order it to them.

I keep progressing, I dismounted and cleaned the rear brake master cylinder that was in very bad condition, probably stocked along many years full of brake fluid that became a sort of paste now. I cleaned every part using WD40 lubrication oil first to remove the dirt and then my plan for the next days is to introduce small metal nuts into the cylinders add vinagger and shake to get a good clean. Finally I will blow air from a compressor.
These are the parts I disasembled and now I need to order a kit of every rubber part.

Starting cafe racer restoration Commando 850 MK3 from Spain

Starting cafe racer restoration Commando 850 MK3 from Spain
 
The rubber boot in the first picture is not the correct item for the Mk3 rear master cylinder.
It should be:
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

The operating rod limit nut (with the groove and facing the wrong direction in your picture) should be set to the dimension below (and locked with the thin nut).
Starting cafe racer restoration Commando 850 MK3 from Spain

Note that the flat metal washer and thinner rubber piston seal with the smaller hole included in the rebuild kit are not used.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

It looks like there could be a circlip instead of the standard safety fastener on the clevis pin.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
(The safety fastener 06.5782 is drawn as a split pin on the parts diagram but that is not correct)
 
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L.A.B. said:
The rubber boot in the first picture is not the correct item for the Mk3 rear master cylinder.
It should be:
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

The operating rod limit nut (with the groove and facing the wrong direction in your picture) should be set to the dimension below (and locked with the thin nut).
Starting cafe racer restoration Commando 850 MK3 from Spain

Note that the flat metal washer and thinner rubber piston seal with the smaller hole included in the rebuild kit are not used.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk

It looks like there could be a circlip instead of the standard safety fastener on the clevis pin.
andover-norton.co.uk

Motorcycle parts and spares for Norton motorbikes - Genuine Andover Norton Spare Parts - Andover Norton Motorcycles Parts - Original Andover Norton Parts

Motorcycle parts and spares for Andover Norton motorbikes: Andover Norton manufactures and supplies all Genuine Factory Spare Parts for Norton motorcycles built before 2002.
andover-norton.co.uk
(The safety fastener 06.5782 is drawn as a split pin on the parts diagram but that is not correct)
Click to expand...
I understand that the flat metal washer include in the rebuild kit is not necessary but looking at Norton diagram it looks to me that the thinner rubber piston seal with the smaller hole is needed to be inserted between the white nylon part over the spring and the metal piston, don`t you think so?

And I do not quite understand from which parts diagram comes the safety fastener 06.5782 which also think is useless.
 
javifoto70 said:
I understand that the flat metal washer include in the rebuild kit is not necessary but looking at Norton diagram it looks to me that the thinner rubber piston seal with the smaller hole is needed to be inserted between the white nylon part over the spring and the metal piston, don`t you think so?
Click to expand...

No, absolutely not. The cupped seal fits adjacent to the white spring part.
Here are the parts in the correct order:

Starting cafe racer restoration Commando 850 MK3 from Spain

That piston seal and flat metal washer are intended for use with a different piston assembly not used on the Mk3 or any other Commando.
Starting cafe racer restoration Commando 850 MK3 from Spain
Starting cafe racer restoration Commando 850 MK3 from Spain

javifoto70 said:
And I do not quite understand from which parts diagram comes the safety fastener 06.5782 which also think is useless.
Click to expand...
Item 25, (drawn incorrectly) retains the clevis pin 23 which would otherwise work its way out without a retainer.
andover-norton.co.uk

Andover Norton Parts Drawings - Genuine Andover Norton Factory Parts - Commando Parts

Andover Norton Parts are the only Norton spare parts in the market manufactured to original drawings, within the factory-approved tolerances, from the correct materials, and with the correct finish.
andover-norton.co.uk

Also, note that the clevis pin retains the short leg of the pedal return spring. The clip, therefore, goes on the inside of the clevis
Starting cafe racer restoration Commando 850 MK3 from Spain
 
Ok understood! But the rubber seal with the small hole is not the one I need to insert on the metal piston?
Starting cafe racer restoration Commando 850 MK3 from Spain

Starting cafe racer restoration Commando 850 MK3 from Spain
 
javifoto70 said:
But the rubber seal with the small hole is not the one I need to insert on the metal piston?
Click to expand...

No, it's the seal with the larger hole (above it in the picture) that fits onto the outer end of the piston which should become clear after you remove the old one.
 
Looking at your pictures on page 1 shows it has rearset footrests so your brake pedal to master cylinder linkage is going to be different to the original.
 
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I rebuilt my rear master cylinder, installed it and never could get it to work properly. Ended up buying a new one and have had no problems since. I also tried to use the original bundy pipes but could never get them to seal properly. Ended up getting new bundy pipes also. I was able to rebuild both calipers. Everything else was replaced with new. The good news is that it stops well and doesn’t leak. Good luck.
 
Larry S said:
I rebuilt my rear master cylinder, installed it and never could get it to work properly. Ended up buying a new one and have had no problems since. I also tried to use the original bundy pipes but could never get them to seal properly. Ended up getting new bundy pipes also. I was able to rebuild both calipers. Everything else was replaced with new. The good news is that it stops well and doesn’t leak. Good luck.
Click to expand...
You may have had a slightly scored or irregular bore that can NEVER seal properly.
 
Larry S said:
I rebuilt my rear master cylinder, installed it and never could get it to work properly. Ended up buying a new one and have had no problems since.
Click to expand...

Yes, the master cylinder (barrel) is often too corroded and scored at the outer end to reuse safely even after some cleaning up.
Personally, I prefer to replace all original barrels or barrel assemblies with stainless steel.

https://montysclassicmotorcyclessho...nless-tr7-t140-t150-t160-norton-mk3-874-p.asp
montysclassicmotorcyclesshop.co.uk

TRIUMPH STAINLESS MASTER CYLINDER ASSEMBLY 99-9918S T140 T150 T160 NORTON MK 3

TRIUMPH STAINLESS MASTER CYLINDER FRONT OR REAR TR7 T140 T150 T160 NORTON MK 3 REAR Complete with stainless piston spring and seals ready
montysclassicmotorcyclesshop.co.uk montysclassicmotorcyclesshop.co.uk
 
javifoto70 said:
I am planning to install an oil pressure gauge to avoid troubles.
I would like to buy this https://www.feked.com/oil-pressure-...-3-8-tapered-26-tpi-thread-liquid-filled.html

It seems includes a 3/8" thread screw, can you tell me which connectors, kind of oil line and oil screw I need to buy to install it?
Are the oil line and connectors the same as the ones normally used as brake line?
Click to expand...
Ready to fit kits, with everything you need, are available from hNw and others.
 
javifoto70 said:
It seems includes a 3/8" thread screw,...

Engine & Transmission :: Engine Lower :: Oil Pressure Valves :: Oil Pressure Gauge - 1+3/4" Diameter With 3/8" Tapered 26 TPI Thread - Liquid Filled

Oil Pressure Gauge - 1+3/4" Diameter With 3/8" Tapered 26 TPI Thread - Liquid Filled. Universal fit as required. Polished stainless steel bezel, chrome plated housing and black face. 0-100 PSI. Standard straight - 45° and 1/2" adapter available.
www.feked.com www.feked.com

Are the oil line and connectors the same as the ones normally used as brake line?
Click to expand...
If "tapered" then it cannot be 3/8" UNF thread.
"Standard 3/8" tapered 26 TPI fitting." isn't anything "Standard" and it's probably 1/8" x 27 TPI, NPT, (tapered pipe*) thread.
*(Pipe threads are described by pipe bore size, not thread diameter)

"45° adaptor: 3/8" inlet and outlet."
Presumably 1/8" x 1/8" NPT?

"Straight adaptor: 3/8" inlet and 1/2" outlet."
?

www.easyr.com.au

V-Factor 88015 Chrome with Black Face 60lb Oil Pressure Gauge 1/8-27npt 1 1/2" o.d Stainless Steel Bezel Weather Resistant Seal Lens

V-Factor 88015 Chrome with Black Face 60lb Oil Pressure Gauge 1/8-27npt 1 1/2" o.d Stainless Steel Bezel Weather Resistant Seal Lens - V-Factor
www.easyr.com.au www.easyr.com.au
"1/8-27npt"
 
As LAB has pointed out there quite succinctly … this ain’t no modern metric machine !

You gotta weigh it up… chances and cost of screwing it up vs cost of an off the shelf complete kit.

Yer pays yer money and makes yer choice…
 
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