[pcoburn]

I'm not sure this will either be a restore or rebuild, but at least hoping to do a refresh over the next few months on my 1979 T140E Bonneville. My current goal is to ride it a bit so I can identify most of what it needs but I did something dumb and broke the clutch perch so unless I can get that fixed quick I might just have to get straight into the refresh!

If anyone has a lead on the bottom part of a left-hand control let me know (I don't need the switches, top part, etc.) The part where the clutch cable adjuster goes through has broken off on the bottom.

Anyway - back to the project - I bought this a few weeks ago and although it doesn't look too bad I want to get it refreshed. After riding it a bit I can see quite a few seals are weeping, a couple of leaks, and there is a bunch of paint missing from the frame, especially around the rear brake system. Everything seems to be there and mostly stock except the rear caliper has been swapped out with a non-OEM version. It has been converted to Boyer electronic ignition already.

So my basic plan is to repaint the frame, re-seal the engine, and undecided on repainting the tank/side panels. They are OK from about 10 feet but have a bunch of nicks and scratches on. Once I get the frame looking good I'm sure I'll want to do something there too!

I've rebuilt a few cars and work on many different type of mechanical projects, but this will be my first big motorcycle project and the first British motorcycle I've owned (I've had a few British cars along the way though).

Here's a picture as it stands today - it will probably be a couple more weeks before I start tearing it down.

 

[GrandPaulZ]

Welcome to the forum!

Looks like the stock rear brake caliper to me...

Nice 10-footer.

 

[pcoburn]

Looks like the stock rear brake caliper to me...

Thanks for the welcome.

The rear caliper is a bit longer than stock so the prior owner “modified“ the bracket to fit.

 

[StuartMac]

Hi,

The rear caliper is a bit longer than stock so the prior owner “modified“ the bracket to fit.

Just 'modify' the bracket completely so the caliper fits properly? The bracket ahead of the caliper mounting now can't serve any useful purpose.

The alternative is to faff around looking for an original Lockheed steel caliper, which - apart from being heavy - will only be available used, with all that entails ...

Afaict, the caliper's either a Grimeca or early Wassell pattern of the Lockheed ally caliper. AP Lockheed cast that on their calipers, Wassell now put "Girling" on their current copies.

current goal is to ride it a bit

Before, I advise investigating the need for the tape on the hose end thread into the caliper. Apart from the hose is a bodge (judging by length of exposed thread, the hose is a front brake part - the one between the slider fender mounting bracket and the lower yoke stanchion pinchbolt?).

Reason I suggest you check this is:-

. if the caliper is a Grimeca, the inlet thread is M10 x 1.0 = 10 mm. nominal major diameter, 1 mm. pitch between adjacent thread peaks or troughs;

. however, the hose thread is 3/8"-24, it'll 'fit' in the caliper because 3/8" is 9.525 mm. and 1 mm. pitch = 25.4 threads per inch; however, the threads incompatibility will leak under pressure (damhikt ), which could be the reason for the tape.

current goal is to ride it a bit
but I did something dumb and broke the clutch perch so unless I can get that fixed

Commiserations. A switch lower half on its own will be difficult unless you happen to spot one on Ebay - the reason they come up is people pull the switches apart, the springs and/or steel ball goes missing, those aren't available as spares either, a complete new cluster is bought and the remaining bits go on Ebay. If you spot one, be quick because there are several like me who know the usefulness of these separate bits and will snap them up.

Risking telling you something you know already, electric-start Norton Commandos used pretty-much the same switch cluster ...

Thoughts to get you to your "current goal":-

. Have the broken perch welded?

. Many Triumphs used chromed steel levers that clamped around the handlebars. Regrettably, although Triumph originally listed clutch and brake levers separately, now they seem to be suppled as a pair. However, as a temporary solution? If you come up with something better later, you can always sell the pair? Another related possibility is try searching for "triumph 60-2242" - that was the part number of the T160 clutch lever, the T160 had a front disc brake, so there might be a dealer selling chromed steel clutch levers on their own using that part number?

Longer-term, if you don't find another perch and neither of the above solutions suit, be aware Sparx have patterned almost all of the original Lucas switch clusters for many years but there is currently a supply hiatus - whether temporary or permanent, I don't know. So you might want to consider acquiring a new Sparx cluster now, against the possibility of needing it at some future time?

Hth.

Regards,

 

[pcoburn]

Thanks for the feedback.

Rear caliper options - I'm looking at a couple of options. 1) the old rear caliper was replaced due to a stripped bleed screw thread. The prior owner provided the caliper and said he'd tried to repair it (you can see the new thread insert in the picture below) but for some reason he said the repair didn't work. If I can figure out the issue/repair the thread I'll just need a new unmodified caliper bracket and be able to reinstall the original caliper. Option 2) is to swap the front and rear calipers - I believe the stock ones are the same front and rear but I'll double-check the parts manual first. In that case I'd also need a new unmodified rear bracket and I'd lose the chrome cover on the front caliper because it won't fit over this larger caliper.

Rear caliper hose - no leaks, I agree it doesn't look good/right but it is secure and leak-free. See above for alternate options I'm considering longer term.

Current goal - the repair I made to the clutch perch seems to be holding, at least for being back on the road. I am watching eBay based on several part numbers - including the Lucas number stamped on the part. I see one out there for what I think is a pretty penny but I may just have to bite the bullet.


One of the main reasons I want to keep riding is to see if I can get the jetting/tuning dialed in. It still doesn't feel right. It pulls great, but on partial steady throttle I can feel what seems like a miss. Valve lash and timing timing are right so trying to see if I can adjust it out with the idle air screws. I cleaned and checked all the ports in the carbs already but I might go through that again if I don't make any progress with the adjustments.

 

[StuartMac]

Hi,

Rear caliper
replaced due to a stripped bleed screw thread. The prior owner provided the caliper and said he'd tried to repair it (you can see the new thread insert in the picture below) but for some reason he said the repair didn't work. If I can figure out the issue

Try a bleed screw with a bottom cone that matches the cone at the bottom of the bleed hole. The cones are the seal, not the screw threads. Trouble is:-

. you can't buy proper Lockheed bits to fit Lockheed calipers, junk is turned out by the Far Eastern equivalents of every Tom, Dick and Harry with a lathe and peddled by certain Britbike parts wholesalers who don't give a monkey's except about money;

. people who shouldn't be allowed big boy's tools don't know bleed nipple cones not screw threads are the seal, and think the fix for a random bleed nipple that doesn't seal is just a bigger wrench ...

I'll just need a new unmodified caliper bracket and be able to reinstall the original caliper.

You know how much heavier the steel caliper is vs. the ally caliper, that weight is all unsprung.

swap the front and rear calipers - I believe the stock ones are the same front and rear

They are.

But, as I say, the steel caliper is much heavier than the ally caliper, the weight is all unsprung.

Also, when you get the ally caliper to the front, even if the inlet thread is UNF rather than metric, the ally caliper inlet isn't at the same angle as the steel caliper's, so you have to replace or bodge the short pipe from the slider fender bracket ...

Bear in mind AP Lockheed always said their rubber hoses should be replaced at most at ten years old, also wise if you don't know how old they are. Now, there aren't any AP Lockheed replacements, it's all pattern. Fwiw, I gave up on the standard steel 'n' rubber mixture decades ago, make my own hoses from Goodridge braided and stainless end fittings, any thread catered, fit-'n'-forget.

I'd lose the chrome cover on the front caliper because it won't fit over this larger caliper.

Ally calipers are bling anyway.

One of the main reasons I want to keep riding is to see if I can get the jetting/tuning dialed in. It still doesn't feel right.

You're aware of the enrichment plunger end seals problem and you've checked for it?

Hth.

Regards,

 

[pcoburn]

Try a bleed screw with a bottom cone that matches the cone at the bottom of the bleed hole. The cones are the seal, not the screw threads.

You're aware of the enrichment plunger end seals problem and you've checked for it?

The bleed screw wasn't included with the caliper so I'll have to source a new one if I want to try to re-use that caliper.

I'm reading up on the enrichment plunger end seals in this forum now - I wasn't aware so didn't do any specific checks. I didn't notice any problems, but will do a closer check.

 

[pcoburn]

I checked the “easy” one and it looked good to me. The “choke” was converted to a cable fairly recently I think so new seals then.

 

[StuartMac]

Hi,

The bleed screw wasn't included with the caliper so I'll have to source a new one if I want to try to re-use that caliper.

Ime, Lockheed bleed screws are 3/8"-24 and the cone has a rounded end rather than a point.

Hth.

Regards,

 

[GrandPaulZ]

I have (5) OEM calipers in a drawer, all of them in fair shape. I think 2 of them have good pucks.

 

[DAVE M]

One “upgrade” when you change hoses is to change the rear switch to a hydraulic one.
some people will throw up their arms but I also use DOT5 fluid front and back.
everything must be flushed through to do this so a hose/calliper change is as good as any time.
I also have stainless pistons in the brakes.

 

[StuartMac]

Hi,

rear switch to a hydraulic one.

+1.

DOT5 fluid front and back.

+1.

stainless pistons in the brakes.

+1.

Or, if invisible bling will satisfy, anodised ally pistons to save a few grammes ...

Hth.

Regards,

 

[pcoburn]

Thanks for all the brake feedback - I will definitely give some thought to the DOT5 conversion, probably a good option for a bike that will probably used less than my "new" bike (2011). Of course once I get it all dialed in that may not be the case any more!

 

[pcoburn]

I’ve been away for a week visiting family in Florida. I did some more investigation today and found the balance pipe (hose) had gone hard so I don’t think it was sealing 100%. Took it out for a ride today after putting a new piece of hose on it and it was an amazing difference. The bike rides great and pulls like a train! There’s probably still some more fine tuning I can do to get rid of a slight stumble accelerating from cruising at about 3,000 rpm but overall it is night and day.

 

[pcoburn]

Winter hit here so no more excuses and time to get started. Got everything ready to take the engine out and did a test batch of hardware to see how it comes out. I've done some nickel plating before but not zinc.

Goal for the next session will be to get the engine out so I just have the rolling frame to deal with.

Where it sits after today -

Sample set of hardware, cleaned, rust convertor, cleaned again and then about 1/2 of them I replated. I only cleaned the chrome screws since they were in good shape. Hard to see from the pictures but I'm really happy with the hardware, it came out almost like new.
Before -

After -

 

[Happyfeet]

Pull the head before you try removing the engine from the frame. In your opening post, you stated your goal was to clear up the oil leaks, so certainly you'll be doing the push rod tube seals. Taking the head off now will make the engine removal easier. At the very least, pull the rocker boxes off.

 

[pcoburn]

Yes on push rod tube seals, those and the front sprocket seal are the biggest areas of leaks I believe.

Everything is apart and bagged (a few components still not broken down like the engine, forks, wheels). I'll work on cleaning everything up, starting with the frame so I can make a decision on touching up versus full respray - I was leaning towards touching up but now everything's off I can see quite a few more chips/rubs than I had before so probably a respray.

 

[Happyfeet]

Looks like winter time fun! Going back to your brakes for a minute, I refreshed a 1979 T140E in winter /spring of 2019. The front brake functioned but the rear brake didn't, so I decided to rebuild both completely including new master cylinders. Here's what my functioning front brake caliper looked like when I opened it up. You might want to look into yours if their condition is unknown to you...

 

[Happyfeet]

The drive sprocket seal will require a couple of the Triumph specialty tools. T-handle clutch spring tool and on the left, the clutch hub puller.

Be SURE to thread the hub puller in as far as it will go so as not to strip the threads on the hub or the puller. Also if you plan to do the seal replacement on the bench, you will find the job much easier with the "clutch locking plate on a stick"tool. The big black sockets made specifically for this job are very handy too, but it can be done with a 1 7/8 inch socket most commonly found in 1/2 inch drive sets. The problem will be with the depth of the socket. This black set is a combo set for both 4 and 5 speed gear boxes. Good Luck and happy wrenching!

 

[pcoburn]

One the brakes - since I'm considering DOT5 conversion I had the rebuild kits on my shopping list (along with new hoses).

On the sprocket seal - thanks for the heads-up, hopefully there's a tool rental thread! I did know someone local to me who was really into British bikes that I'm sure would have had access to a few special tools locally but unfortunately he passed last year.

I haven't decided on the order I'll work on things, but at least assembly-wise I'll probably follow the reverse of disassembly - basically I got down to a basic rolling chassis, then took the engine out, and then removed the wiring harness, then the wheels/forks/swing arm. I don't have a lift table so keeping the bike on wheels means I'm not crawling around on the floor. Since it will probably be too cold to paint here soon I'll work on getting each of the components ready that don't need paint - engine, brakes, forks, etc. so when it does warm up I should be able to move pretty fast.

Very last thing will be refinishing the tank / side panels, no decision made there yet. If I go back to stock '79 colors I'd lean towards the red/black or black/red but I also like some of the blue/white combinations from other years.