[Lake Marine]

I replaced the seals and reassembled my rear master cyl assy but I dont remember or have photo of where a "slotted barrel nut" is supposed to go and the manuals dont show it. The best of my recollection it was in the position in the attached photo but not sure. I dont believe it was doing anything where it was but it may have loosened up over the years and maybe it some odd jam nut?
Anyone have insight on where this "nut" goes?
Thanks - LM

 

[Rancidpegwoman]

Hi LM
It is the locking (jam nut) nut for the other nut that is securing your rubber dust cover.
you need to lock the other nut 9mm away from the master cylinder body.

If you have not set one of these up before, follow the instructions in this bulletin to the letter, the Lockheed master cylinder does not work on the same principles as most other brands, it has a unique pre-primed system to deliver the brake fluid faster, but it requires a precise set-up.

http://www.classicbike.biz/Triumph/Maintenance/LockheedBrakes/Lockheed_Hydraulic_Brakes_Triumph_Norton.pdf

best regards
Peg.

I have just spotted that Stuart has already sent the lockheed bulletin in a previous thread.

 

[Lake Marine]

It is the locking (jam nut) nut for the other nut that is securing your rubber dust cover.
you need to lock the other nut 9mm away from the master cylinder body.

I have just spotted that Stuart has already sent the lockheed bulletin in a previous thread.

Thank you Peg - Yes Stuart did provide bulletin and I printed it and took to my shop but I only printed the detailed pages and did not print the first page...duh.
I now see it in the diagram and I thought that was where it should go. It is baffling why they just didnt use a standard jam nut. I guess I can snug that up with a screw driver of sorts.
Also - yes i did read the 9mm adjustment distance. I followed the instructions closely and I ended up at .34" distance. Another half turn on the cast body probably would have gotten me another .02" but what the diagram does not show is the way too long set screw and lock nut that seats on the flats milled on the male threads of the cylinder (there are two flats 180 apart but the one inline with the reservoir stud/ports is useless in this application bc If I turned it another half turn the reservoir hose barb lands directly over the set screw creating an interference. (Let alone trying to slide the reservoir hose on) The diagrams don't show this set screw or give a detailed view of the pushrod assembly.
Anyway...I did get it back together and the pushrod/piston feels good. I currently have the assembly setup in a vise with an elevated temporary "reservoir" and primed the cylinder and checking for leaks overnight.
Thanks for the help! LM

 

[Rancidpegwoman]

If you have trouble bleeding the caliper, you might need to remove the bolts and hold it with the bleed nipple at the top.

 

[StuartMac]

Hi,

baffling why they just didnt use a standard jam nut. I guess I can snug that up with a screw driver of sorts.

The assemblies AP supplied for the T160 (earlier than the twins) do have a standard hex. nut jam/lock nut. Baffling is why that was changed for something that couldn't be tightened/loosened with a bog-standard 7/16" AF open-ended spanner/wrench ...

9mm adjustment distance. I followed the instructions closely and I ended up at .34" distance. Another half turn on the cast body probably would have gotten me another .02"
set screw
that seats on the flats milled on the male threads of the cylinder

Mmmm ... for clarity:-

. the linked Lockheed instructions show to set the master cylinder and pushrod in the mounting casting before setting the clearance of the 'boot nut';

. the master cylinder's external mounting thread is 1 mm. pitch; i.e. a complete turn of the cylinder moves it in/out 1 mm.; therefore, having: removed all "lost movement" between master piston and pushrod, turned the cylinder "one complete turn" (1 mm.), the following "part of a turn" moves the master cylinder into the casting less than another mm.;

. then the 'boot nut' clearance is set to the ~3/8" and the nut locked on the pushrod thread;

. however, the given measurement is a ridiculous level of precision; all that's actually required is: the 'boot nut' isn't so close it hits the mounting casting before the master piston's full travel; the 'boot nut' isn't so far from the mounting casting the boot's pulled off either the casting or the nut's lip.

what the diagram does not show is the way too long set screw and lock nut

Ekshully ... they're peculiar to your master cylinder mounting ...

Original locking Allen grubscrew is 10-24 before 1980, M5 (5 mm.) after. It's about the same length as the mounting casting thread so, when it's screwed down to lock the master cylinder, the top of the grubscrew is below the outside of the casting ... I usually smear a lump of grease in on top of it to keep road crap out and the grubscrew in even if it comes loose.

By eye, the setscrew in your photos. is 1/4"? If so, someone's been there before you, drilled out a corroded? original grubscrew, mullered the original casting thread, drilled 'n' tapped it to the next size up bolt he had lying around? Whether it's 1/4" or original 10-24, just replace with a shorter/standard grubscrew?

Hth.

Regards,

 

[Lake Marine]

set the master cylinder and pushrod in the mounting casting before setting the clearance of the 'boot nut

Yes. Any other way would be pointless. They show it as the last thing to do before leak test.
1MM TPI - 1/2 rotation would advance .02" (.5MM) and I also think it is being overly precise and I fell comfortable with the positon so no need to shorten the grub screw.
The casting has a full ~1/2" dia. X ~.06 boss spotfaced to seat the jam nut to lock the 5/16-24 grub screw. Since I bought bike new and feel I can tell (35 yr retired machinist) and/or remember if that part has been modified!
The front cylinder does have #10 grub (3/32 Allen) that was an SOB as I had to heat it to get it out (bad design). It has a woodruff cut keyway to seat the dog point of that #10 grub and also has a full 1/2" wide flat milled 180 degrees apart (possibly for the larger set screw if the cylinder were fitted to the rear casting etc). This all appears by design unless someone at Lockheed or Triumph said they were tired of stripping that 3/32" allen wrench or breaking taps and took it to the extreme!

 

[StuartMac]

Hi,

Since I bought bike new

😔 Slipped my mind, my bad.

Nevertheless, 5/16" -24 locking grub screw on the rear master cylinder is uncommon (my get-out for any "I've got one" posts that follow ) Five Lockheed/Triumph master cylinders in my garage now, two of those are twin-disc replacements for earlier single-disc ones, Gk how many others I've had dealings with in over forty years, never seen another grub screw like your bike's rear.

Also possibly connected, your bike's rear mounting casting is unpainted; again, never seen another one new like that.

front cylinder
grub
an SOB as I had to heat it to get it out (bad design).

Not really. Ime, the British automotive industry never assembled fasteners with moisture-excluding grease (nor does the modern automotive industry?). Did you disassemble the front master cylinder in the last 44 years and grease either master cylinder or grub screw? Otoh, it so happens I disassembled my T160's master cylinders no later (possibly earlier) than six years after they were assembled; even then, I was replacing those grub screws with stainless as a matter of course and greasing both grub screw and master cylinder threads when reassembling (given your username and location, you don't assemble threaded components with grease? ).

In addition to the humungous grub screw in your bike's rear master cylinder mounting, your bike's front master cylinder is also odd - every AP Lockheed-made master cylinder I've ever seen has the two wide grub-screw-locating flats like your bike's rear one.

Btw, given the threads on these master cylinders, not sure why but the two flats by the hose outlet are spaced for a 3/8" British Standard (called "Whitworth" by many of your countrymen) wrench.

Hth.

Regards,

 

[Lake Marine]

I’m just glad I can free support! The huge grub might be unusual but I’m glad it was there as so much easier to disassemble. I took them off but never rebuilt them in all those years. I replaced pads and obviously bled them though maybe in 80-82ish.
I’ve swapped out for SS hardware where I can. Whitworth hardware is hard to find especially in SS so if you know where let me know. It’s funny you say that as UPS just delivered my whitworth wrenches!
I use N5000 antiseize graphite grease and loctite where needed to lock.
Rebuilding the front now then the Amal’s. I’m getting price and lead time on the Dunlop, Avons and Continentals so I’ll decide and have new tires soon!
Thanks for the free tech support to all!
LM

 

[StuartMac]

Hi,

swapped out for SS hardware where I can. Whitworth hardware is hard to find
UPS just delivered my whitworth wrenches

Mmmm ... for clarity, "Whitworth" is correctly British Standard. I think the last British Standard fasteners on Triumph twins were the 2BA screws and Cycle-thread drain plugs on T140V and TR7RV Amal Mk.1 carbs.

Someone'll post a correction but, off the top of my head, I can't think of any British Standard/"Whitworth" threads on your bike; they're almost all American Unified - mostly UNF and UNC, smattering of others like UNS and UN Constant Pitch; wrenches should be AF. Amal Mk.2 hardware is metric?

Hth.

Regards,

 

[Rancidpegwoman]

Triumph fitted 2ba x 5/16" countersunk screws to hold on the sprocket inspection cover behind the clutch, right up until the end of production.

The 9mm gap on the ’boot nut’ is to limit the piston travel down the bore so that the spring button behind the seal does not hit the bleed assist check valve too hard during bleeding.

check valve

valve dismantled

 

[Lake Marine]

Amal Mk.2 hardware is metric?

I sent an email last week to Amal as neither my SAE or Metric wrenches fit for some of the Mark II hardware and below is a list they provided. I bought a set on Amazon for about $40US
I guess I also considered the filister head screws in conjunction with whitworth in error. I'll check on McMaster-Carr and see what they may have. I need to replace the fillister head screws for the handlebar switches. I could probably use SHCS though which i'd prefer over a flat head or a phillps anyway.

Good Afternoon,
Thanks for your email.
I am sorry we don’t stock the spanners however please see below the spanners we suggest for our carburettors.

Pre Monobloc 276 & 289
Needle Jet	3/16" BSF or 1/8" Whitworth
Main Jet	5BA
Holding Up Bolt	7/16" BSF or 3/8" Whitworth
Banjo Nut	5/16" Whitworth or 1/4" Whitworth
Outlet Clip Screw	3/16" BSF or 1/8" Whitworth
Float Chamber Lid Bottom Feed	5/16" Whitworth or 1/4" Whitworth
Float Lid Clamp Screw	3/16" BSF or 1/8" Whitworth
Platform Plug Screw	3/16" BSF or 1/8" Whitworth
Throttle Stop Screw Locknut	3/16" BSF or 1/8" Whitworth
Mixing Chamber Union Nut	9/16" BSF or 1/2" Whitworth
Monobloc
Banjo Bolt	5/16" Whitworth or 1/4" Whitworth
Float Needle Seating	1/2" BSF or 7/16" Whitworth
Tickler Body	1/4" BSF or 3/16" Whitworth
Pilot Jet Cover Nut	3/16" BSF or 1/8" Whitworth
Main Jet Cover Nut (original)	3/8" BSF or 5/16" Whitworth
Main Jet Cover Nut (new)	7/16" BSF or 3/8" Whitworth
Main Jet Holder	1/2" BSF or 7/16" Whitworth
Main & Needle Jet	8mm or 5/16"AF
Concentric MK1
Jet Holder	5/16" BSF or 1/4" Whitworth
Banjo Bolt	5/16" BSF or 1/4" Whitworth
Main & Needle Jet	8mm or 5/16" AF
Concentric MKII
Jet Holder	5/16" BSF or 1/4" Whitworth
Banjo Bolt	5/16" BSF or 1/4" Whitworth
Main & Needle Jet	8mm or 5/16" AF
Drain Plug	20mm
Cold Start Plunger Nut	13mm

Kind Regards

Customer Services Advisor

Burlen Limited - The SU, AMAL & ZENITH Carburetter Companies Spitfire House, Castle Road, Salisbury, Wiltshire. SP1 3SA Tel: +44 (0)1722 412500 Fax: +44 (0)1722 334221 Email: [email protected] Website: http://www.burlen.co.uk

 

[Lake Marine]

The 9mm gap on the ’boot nut’ is to limit the piston travel down the bore so that the spring button behind the seal does not hit the bleed assist check valve during bleeding.

Pegs - Thanks for the cylinder breakdown! I feel much better about my .34" measurement now. Also - that is one fine looking cylinder! I think mine have a poor mans galvanize! Your threads look a little flat (probably from the polish-wish i had a lathe!) but im sure they'll hold! Here is what mine looked like after 40 years of neglect. Both F&R were a bear to get apart and clean.

 

[Rancidpegwoman]

Hi LM
you might need a cylinder brake hone to recover the inside sealing surfaces. $10-$15 on E-bay/harbour freight

The cylinder in the photo is an aftermarket stainless steel item, that probably accounts for the shiny surface and poorly cut threads.
It has been replaced with a smaller diameter 13mm bore version.

 

[Lake Marine]

you might need a cylinder brake hone to recover the inside sealong surface

Sorry that photo was a “before” photo from a few days ago but… Yes!! I have a hone as well as some bore brushes. I’ve got them both all cleaned up and reassembled as shown in the earlier photos!

 

[Lake Marine]

The cylinder in the photo is an aftermarket stainless steel item, that probably accounts for the shiny surface and poorly cut threads.
It has been replaced with a smaller diameter 13mm bore version.

Peg - I ordered/received a Front Master Cyl Kit from a US Bonneville parts supplier. While installing the piston seal I thought it looked way too small but it was the only one supplied in the kit so I proceeded. That seal was a PIA but I got it on and though it looked odd, I reassembled and it seemed to hold pressure but I felt uneasy about it so I disassembled comparing to the old seal. Then re-reading your comment on the 13mm bore version (I didnt know existed) and then looking at the website photo it struck me. I beleive I received a kit that had a piston seal for a 13mm cylinder (?) but was missing the seal for my size cylinder (also was missing the reservoir o-ring). When I finally received a response from the supplier I was told to, "place another order while they decide how to proceed with the matter....etc. etc." That set my jaw as I had ordered $700 in misc. parts taking 10 days to receive. (I know Im raking them a bit).
I have had some some tips on alternate part suppliers from another seasoned forum veteran and have had good luck with those so far.
Just thought I'd share this experience and thanks again for your detailed info - otherwise I would not have known!
LM

 

[StuartMac]

Hi LM,

Front Master Cyl Kit
installing the piston seal I thought it looked way too small
beleive I received a kit that had a piston seal for a 13mm cylinder (?) but was missing the seal for my size cylinder (also was missing the reservoir o-ring).

Uh-uh. The "Lockheed" that supplied Triumph with disc-brake components never made a 13 mm. master cylinder, they're an aftermarket thing - the 13 mm. piston and seals aren't the same as AP Lockheed supplied Triumph (iirc, the piston has only one seal, not two like the Lockheed?)..

The seal you received and fitted was in every original AP Lockheed master cylinder seals kit. Dunno what it fits; the smaller hole suggests there are pistons around with a smaller-OD shaft in that area? However, that "it seemed to hold pressure" means the seal's OD is correct for a standard Lockheed single-disc master cylinder, which are 5/8" ID so some 3 mm. bigger than 13 mm.

When Lockheed supplied Triumph, the "AP" was the British automotive components supplier Automotive Products, Lockheed was one of its 'names'. Regrettably, AP closed in 2000 and its various 'names' were sold off - iirc, "Lockheed" was bought by an Indian company? Anyroadup, many "Lockheed" components that fit our old heaps are made by pattern parts makers; I suspect whoever supplied the vendor you bought from simply has the common pattern parts makers' quality control.

Hth.

Regards,

 

[Lake Marine]

However, that "it seemed to hold pressure" means the seal's OD is correct for a standard Lockheed single-disc master cylinder, which are 5/8" ID so some 3 mm. bigger than 13 mm

The OD and taper was same but thickness and ID were not. If the kit included the seal i needed (and shown in their web photo) I would have flicked that little one to the side and moved on. I think someone shagged the common seal and o-ring from the kit and resealed it and no one noticed it when it shipped. 🤬

 

[Rancidpegwoman]

Hi LM,
I think the photo on their site is wrong it seems to show the wrong main seal, as for the kit there seems to be just the ‘O’ rings for the reservoir that are missing.
This is what I would expect in a seal kit-note the main seal is a cup seal, it should be quite floppy .

In your disassembled photo, the end seal on the pencil is the correct way around, the end seal on the piston appears to be backwards, it might be a trick of the photo though. You usually have to fight this seal on to the piston, it’s a tight fit.


the wavy washer is important to release the cup seal from the piston.

If this was a 13mm kit it would be very different, they have been built on Japanese/Brembo principle, not this lockheed one.

best regards
Peg

 

[Lake Marine]

the end seal on the piston appears to be backwards, it might be a trick of the photo though. You usually have to fight this seal on to the piston, it’s a tight fit.

It appears backwards bc it is a .19ID X .15THK cup seal forced onto a .375OD X .23W piston journal causing deformation. The original seal has a .36ID X .22THK. Yes the correct size seal (as was in the rear kit) was a fight to put on. However, the unbeknownst wrong front seal I received was a 🤬. Also the wavy washer (s) in the kit are flat. The kit was advertised as a “front” only. IF I had received what was advertised and ordered on the Bonneville Shops website as shown in their picture I would have had no issue other than the supposed wavy washer!
Have a great weekend!

 

[Lake Marine]

Help! Can anyone tell me where to find the parts manual showing the rear brake configuration in this photo? I have the parts with the two black arrows pointing at them but I cant find in any manual other than the the 73-78 service manual.
I added a few more photos. My problem is the shouldered/journal protrudes through the large bracket an extra .03 then the 3/8-24 lock nut won’t tighten so maybe I’m missing a special washer? The shouldered dia is .57 There’s no paint on the bracket/shoulder piece as my rust remover took it off.