Restoration

[Neil Yardley]

I am currently working to get a 1978 Silk 700 that has stood for a good few years through its MOT. At the moment I have Several issues. But at the top of my list are fork Seals & Front brake master cylinder seals, both of which are leaking fluids.. Could anyone help me with where I might be able to Source replacement fork seals & a kit to restore my AP Lockhead master cylinder..

[Hendred]

The Technical Data section on this site says the fork seals are 38x50x7, two off per leg.  Should be available from a bearing supplier such as Simply Bearings or Bearing Boys.  The front brake master cylinder seals and other spares are available from Andover Norton.  Different size of master cylinder bore depending on single or double disc front brake.  Look on the AN website or give them a call.  They are very helpful.

[Smokey_Paul]

Check for number of cut groves on the hose connector area of the master cylinder this gives the bore type.

Once I know this I can give you the original part number for Ap lockheed parts.

Regards

Paul

[Neil Yardley]

Thanks for the replys.. The Master cylinder has 2 thin radial grooves near the fluid fitting & the bike is a twin disc with version with Spondon Calipers.

As for the Fork seals I tried Simply Bearings & a few other bearing suppliers & they don't list a 38-50-7 Fork Seal.. They do list a bearing seal in that size but they are for rotating shafts.. A scan of ebay did come back with 38-50-7/8 Fork seals. Would they be ok.. Sorry I am new to all this.. I usually bang in a reg number or Make n Model then order the part for the bike.. Even then its amazing how often the wrong thing turns up..

Neil.

Ps I got the chain fitted (that was fun).. & I can select gears, but pulling in the clutch when in gear does not appear to isolate rear wheel from the crankshaft (I am testing it without the engine running).. Obviously that is a normal situation for a bike that's been static for a while, but am I looking at a major job.. Or is there a procedure for freeing it up.. I don't really fancy getting it running then slamming it in gear with the clutch in & the brakes on..

[Hendred]

I expect Paul will get back with the master cylinder repair kit number.  A good site for identifying your brake parts is:

AP Racing - Motorcycle - Classic Range - Spares for classic equipment

Don't see why the 38 - 50 -7/8 seal won't fit. The 7 refers to the thickness of the seal body and the 8 to the overall height. The lip is slightly proud of the body.   I was looking at the ARI.029 seal.   Not having tried one I can't be sure though. Somebody else may know for certain.

I free my clutch by a kicking the engine over with the clutch lever pulled.  It has always worked so far but I expect my bike hasn't been left standing so long.  It isn't difficult to take the clutch apart for cleaning. It can be accessed by removing the gearbox final drive sprocket.  If you haven't got a manual for your bike you can download one from this site.

Hope this helps.

[Neil Yardley]

Ooops sorry Paul did I really say radial.. no the groves run around the housing, well one of them does the other kind of stops and starts.

Well the ARI.029 is the one I was looking at.. From scanning around the web it is mentioned that spondon forks may have used Marzocchi internals. I don't know if that's true or not..

I think I will try the clutch in kick start method first, The thought of removing the gearbox sprocket/ cover or more especially having to fit it again does not exactly fill me with joy.. Although I dare say its easier second time around..

[Hendred]

To gain access to the clutch is fairly straight forward if you follow the instructions in the manual.  The string holding the ends of the chain together makes refitting the chain easier.  Several of us have struggled fitting new chains, especially through new gaiters.

[Smokey_Paul]

Having trouble finding part numbers but if you call Andover Norton with the details they do the genuine kits for AP. Telling them double grove will help that is how I got the number in the first place for my repair kit.

Sorry will keep looking and add it to the site when found

[hendred]

Part number for the 2 groove master cylinder is CP 2410-10, repair kit is CP 2410- 1RK.  Recommend checking on the AP Racing website that is the master cylinder fitted on the bike - things get changed over the years.  The repair kit is quite expensive now so be sure you get the right one.  This is the 0.7 inch bore master cylinder.  Just the piston seals used to be available but AP only list the full repair kit now.  Andover Norton may still have just the seals. The full repair kit seems to cost about £50 now!

Just for reference, the 0.625 inch bore master cylinder on the single disk is CP 2215-10. The part number changes to CP 2215-20 and the repair kit is listed as CP 2215-20RK.  Why I don't know. Used to be able to find all the part on the​ Andover Norton site but I can't find them there any more.

Hope this helps.

[Neil Yardley]

Thanks Hendred (& Smokey Paul), you are spot on took a Mic to the Piston & its just on 17.70mm Sorry my imperial mic is at the back of a drawer somewhere.. But that works out at just on 0.7".

I also had a go at freeing up the clutch using the kickstart as you suggested but Its stuck fast.. So I am going to have to learn that Indian rope trick of yours.. How long do you make the string link in the drive chain & wouldn't it be better made of something 'formable' like wire..

While I am on it, I replace the old fork oil with 0.25 litres per leg of new oil only to find the seals have gone but at the time 0.25 litres seemed rather a lot ?.

[hendred]

Suggest calling Andover Norton about the master cylinder spares.  They list the parts used on Nortons separately and they are a lot cheaper than a repair kit. Just quote the master cylinder number.

The string or wire isn't long.  If I remember correctly, I removed the spring link at the gearbox sprocket, tied the ends together with a piece of string.  Pulled the chain back to clear the sprocket for removal.  Reverse procedure to refit.

You are beginning to discover the quirks of the Silk.!  My original manual was heavily hand corrected and the quantity of oil for the forks has been changed to 200cc.

[Neil Yardley]

Ooops I just contacted Andover Norton for a quote on the kit & fork seals, & There was a kit listed on ebay. Andover Norton were dearer on the kit & couldn't do the seals so I ordered the ebay one.. I think I need the full kit, Having stripped it the boot is knackered & the toothy washer is largely missing..

Really. on this one the Gearbox Sprocket is Attached to the inside of its cover.. Admittedly I never dis'assembled the bike but the only way I found to get the chain in place was by fitting the spring link at the back of the rear wheel sprocket once everything else was in place (Nightmare).. Is there a way to get the gearbox sprocket cover off without first drawing out the chain..?

Hm yes I can't say I'm impressed with the whole integrated front mud guard double disc cover situation. The discs rub on their covers & the whole thing makes it difficult to get the front wheel out.. .. I Don't want to moan but it certainly does have some quirks..

[hendred]

It's coming back to me now.  I pulled the string round the gearbox sprocket from the rear chain enclosure so the loop of string let me remove the cover.  Have to remember to loop the string round the sprocket when replacing.  It was some time ago I did this, can't remember why now!

When I got my Silk the ears over the brake discs were pulled back with cable ties to stop them rubbing and it is pain getting the front wheel out.  Have fun!

[Smokey_Paul]

Yes I agree found my parts kit I used cp2410.
Silk owners need a good sense of humour sometimes and the front wheel and mudguard arrangement is one of those times😉
Once you learn the tricks you will enjoy ownership and make a few friends who will know more about the bike than you lol

[Smokey_Paul]

I think I have a spare sprocket and case like the type you have

[Neil Yardley]

Master Cylinder repair kit turned up.. Blimey.. Never.. in the field of bike restoration.. Has someone so tight paid so much for so little.. Jeez.. Well I haven't been doing it long..

By the way, Its not actually my bike.... I'm fixing it up for a friend..  

[Neil Yardley]

Finally got the front wheel out by fully deflating the front tyre & sqeezing it through between the bunny ears.. well it had been a long day .. Anyhow still couldn't get the mudguard out so took a hacksaw to it  Not really. I removed both lower tubes together. Those bottom bolts were in tight, turned one of my alen keys into a cork screw.. Anyhow I now have the sliders off & clear but the seals seem different to the write up in Technical data downloadsI can't see any circlip.. & both seals appear to be pointing in the same direction.. which seems logical.. So I will fit the new seals the way the old ones came out unless anyone tells me otherwise. Oh and I plan to fit a pair of ARI 029's to the outside.