Bringing My '79 Bonneville Special Back to Life

grandpaul said:

AH! You got me! This is a Norton forum, but I forgot we were on "other brands" section.

Okay, employing my best Gilda Radner as 'Emily Latella':

"NEVER MIND".

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Hang in there, Grandpaul! You may have missed this one but I printed off your instructions for separating the clutch discs, used them for the work, and made them a permanent part of my Factory Manual!

When I finish the Triumph, I'm going to drag the Norton out of mothballs and start preparing it for market. I'm hoping I can make a much better thread, including pictures, of the process. I look forward to your help then as much as now!

Al

Tulsaalva said:

I've replaced the rubber parts, inspected the pristine bore, and reassembled the front master cylinder. I've found that the two parts screw together much more easily. Should I use some sealer on the threads?

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Personally, I use grease.

The number of turns that the barrel assembly has to be screwed into the casting is critical.

Hopefully the instructions giving the assembly procedure were included with your seal kit?

L.A.B. said:

Tulsaalva said:

I've replaced the rubber parts, inspected the pristine bore, and reassembled the front master cylinder. I've found that the two parts screw together much more easily. Should I use some sealer on the threads?

Click to expand...

Personally, I use grease.

The number of turns that the barrel assembly has to be screwed into the casting is critical.

Hopefully the instructions giving the assembly procedure were included with your seal kit?

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I used the instructions in the Factory Manual, L.A.B. (There were no instructions included with the parts.) It seems to have worked just fine. Of course, I can't be sure until the whole thing in assembled and can be tested. I used anti-seize on the threads.

I'm back at a standstill because the Russell parts I need were partially back ordered. I need three adaptors and got one. I need three banjo bolts and got two. At this point, they're pretty much useless chunks of chrome. Pretty, though!

Al

Tulsaalva said:

I used the instructions in the Factory Manual, L.A.B. (There were no instructions included with the parts.) It seems to have worked just fine. Of course, I can't be sure until the whole thing in assembled and can be tested. I used anti-seize on the threads.

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If you followed the procedure in the manual then everything should be OK. However the manual way is the 'old' way, as Lockheed did revise the assembly instructions for setting the barrel to the correct position. The important thing is that you can actually blow air or push fluid backwards through the master cylinder assembly with the piston/lever in the fully off position.

I've decided to give up on the Russell brake lines. I've still not been able to get the right banjo bolts and adaptors.

The main reason, though, is that I stopped by Tulsa Brake and Clutch and found that they have on staff a fellow who makes bespoke braided stainless steel brake lines. They're even D.O.T. approved, and can be made exactly like the stock ones, except the material, of course. That means they will fit the factory brackets on the front forks, which the Russell parts would not do.

They should be ready on Tuesday!

For Sale: One almost-complete set of braided stainless steel brake lines that almost fit a '79 Triumph Bonneville Special.

Al

L.A.B. said:

Tulsaalva said:

I used the instructions in the Factory Manual, L.A.B. (There were no instructions included with the parts.) It seems to have worked just fine. Of course, I can't be sure until the whole thing in assembled and can be tested. I used anti-seize on the threads.

Click to expand...

If you followed the procedure in the manual then everything should be OK. However the manual way is the 'old' way, as Lockheed did revise the assembly instructions for setting the barrel to the correct position. The important thing is that you can actually blow air or push fluid backwards through the master cylinder assembly with the piston/lever in the fully off position.

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I did follow the instructions to the letter, L.A.B., even bolting the master cylinder to the switch bracket to do the work. It seems to have worked fine. I kept the lever squeezed against the handlebar grip during the process. Is that what's meant by the "fully off position"? If not, I'll have to do it again, I suppose.

Al

Tulsaalva said:

I kept the lever squeezed against the handlebar grip during the process. Is that what's meant by the "fully off position"?

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I would consider that to be the fully on position, and 'fully off' with the lever released, which is how the revised instructions say to do it.

The important thing is to check that the brake fluid is able to pass from the brake line back to the reservoir through the tiny return bleed port when the brake is fully released? Which is best done after assembling the unit by testing if air can be blown 'backwards' through the master cylinder, or it can be tested after the system is bled by pushing the caliper pistons back and observing that the fluid level in the reservoir rises as a result.
The reason for the test is that if the barrel assembly is screwed even one turn too far into the housing, then the master cylinder piston will be set too far into the cylinder, the piston seal then covers the bleed port, and any excess pressure that builds up in the brake system cannot escape by venting into the reservoir, the result will be a dragging brake as the pressure in the system will push against the caliper pistons and so drag the pads against the disc.
This also applies to the rear master cylinder assemblies on rear disc Triumphs, and 850 Mk III Commandos.

Torque specifications for banjo bolts

Hi, Y'all!

I picked up the new brake lines and have been installing the rear brake system today. All is together and fitting quite nicely. The braided stainless steel brake lines look great and I'm sure they'll perform at least as well as the originals.

Here's my question: I like to torque fittings. That old business of "tighten securely but do not over tighten" just doesn't do it for me. Of course, there are no torque specifications for the banjo bolts in the factory manual nor with the Russell parts.

I've opted to use the Russell banjo bolts because they fit perfectly and came with aluminum crush washers quite similar to the ones used on BMW drain plugs, which seal very well. Also, the banjo bolts are chrome and pretty.

I'm thinking fifteen foot-pounds should crush the washers enough to seal the brake lines. Is that too much? The BMW manual specifies 15 to 18.7 foot-pounds for the oil drain plug, which is a bit bigger than the banjo bolts I'm working with.

Any opinions?

Al

Wheel alignment

I'm thinking forward to aligning the wheels. I've read the factory manual which suggests using straight edges (boards) abutted to the rear tires while reaching forward on each side of the front tire. One then measures the distance between the edges of the boards and the edges of the front tire on each side.

However, I have a couple of laser tools and am thinking of putting them into service for this task. Here's my plan:

The bike is sitting on a rolling platform which holds both tires about six inches off the ground. I built the mount on which the Bonneville sits so that the bike is perpendicular to level. My garage floor is level in one direction which is how I'll orient the motorcycle.

Both tires have a center groove. If I place the laser behind the bike and aim the beam at the center groove of the rear tire, it should hit the center groove of the front tire as well, assuming alignment is correct. If it doesn't, it should be a simple matter of adjusting the pull bolts on the rear of the rear swinging arm and readjusting the laser until the beam follows the center groove of the rear tire and also falls into the center groove of the front tire.

It sounds better than two boards and a ruler to me. What do y'all think?

Al

Re: Torque specifications for banjo bolts

Tulsaalva said:

I'm thinking fifteen foot-pounds should crush the washers enough to seal the brake lines. Is that too much? The BMW manual specifies 15 to 18.7 foot-pounds for the oil drain plug, which is a bit bigger than the banjo bolts I'm working with.

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Not only are the BMW washers/drain bolts a larger diameter, but also a coarse metric thread pitch? So I can't see how using the BMW figures is going to be any more scientific than the "tighten securely but do not over tighten" method, which I must say is all I've used up 'till now, although I've only used copper washers on banjo fittings, -as far as I can remember anyway?

Tulsaalva said:

If I place the laser behind the bike and aim the beam at the center groove of the rear tire, it should hit the center groove of the front tire as well, assuming alignment is correct.

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Theoretically, there's no reason that I can think of why that wouldn't work.

Please let us know how you get on?

Good point, L.A.B. I hadn't thought of the different thread pitch making a difference in the torque settings. As a matter of fact, I think the hardware store carries copper washers. I don't care to use the old ones.

Thank you!

Al

Okay, Y'all... I have another embarrassing question.

In the bag of parts for the front brake hardware, I have two light springs that are about one inch long and .25 inch in diameter. I don't remember removing them but they wouldn't be in the bag if I hadn't.

They fit between the brake pads with the split pin through the center. To me, it seems they will ride very close to the edge of the disc if installed that way and may foul it.

There were no such springs on the rear caliper. No springs came with the new brake pads. No such springs are shown in any drawings of the calipers in the factory manual.

Have I guessed the location correctly? If so, must I order replacements for the rear brake pads?

Thanks in advance! I shudder to think where I'd be on this project without y'all!

Al

Tulsaalva said:

Have I guessed the location correctly?

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Yes.

Tulsaalva said:

If so, must I order replacements for the rear brake pads?

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No!

As the springs are an 'anti-pad-rattle' modification, commonly robbed from a couple of ball-point pens!

Thanks, L.A.B.!!!

I have a lot of ball point pens around the house. My guess is they'll work even better than these and, with their smaller diameter, pose less danger of fouling the edge of the discs!

You rock!

Al

Wheel Alignment

I found out the job is best done with two lasers, one in front of the bike and one behind.

I aligned the front laser with the center groove of the front of both tires and the rear laser with the center groove of the rear of both tires. Unfortunately, the beams crossed.

I decided I should do a "rough" alignment first, so I adjusted the pull bolts until I had exactly the same distance between the adjusters and the backs of the rear swinging arm, and three-quarters of an inch of chain play.

I set up the lasers again in the same way as above. When all was done, the front laser was centered in the center grooves of the front of both tires, the rear laser was centered the same on the rear of the tires. To my pleasure, the beams both hit the lenses of their opposites.

The actual adjustment was done by measuring the distance between the adjusters and the rear of the swinging arm, not with the lasers. Although the lasers did confirm the alignment, I have to admit that I spent at least an hour and a half doing a job that should have taken fifteen minutes.

Ah, what the hell? It was fun and that's what fixing these old bikes up is all about, nicht wahr?

Al

L.A.B. said:

Tulsaalva said:

Have I guessed the location correctly?

Click to expand...

Yes.

Tulsaalva said:

If so, must I order replacements for the rear brake pads?

Click to expand...

No!

As the springs are an 'anti-pad-rattle' modification, commonly robbed from a couple of ball-point pens!

Click to expand...

I have a box of advertising ball-point pens in the attic from a business we closed over ten years ago. The result is that I have four springs exactly alike. The one's my friend used looked home-made out of another spring. The installation looks "original factory," and doesn't even come close to the edge of the disc!

Thanks, L.A.B.!

Al

I've not actually found the spring 'modification' to be all that effective myself, maybe the springs I used weren't strong enough?

The reason for the modification is that some brake pads are quite a loose fit in the caliper slots, so have a tendency to chatter (clicking noise) at low speeds. The original Lockheed pads fitted to my T140V Bonneville do not seem to rattle at all, unlike the aftermarket pads that came fitted to my twin disc modified T160 Trident when I bought it! I did the spring modification to that, but it wasn't a complete success.

I've measured three different makes of pads and the overall length does vary. I found the EBC HH pads to be the best fit, closely followed by the old Lockheeds.

Here's something I wrote about that in a reply on the TriplesOnline website forum some while ago:
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....The metal pad backing plate of the EBC HH being the longest of them all @ 59.57mm, Lockheed @ 59.5mm, unknown @ 58.9mm, the HH fits into the caliper slots quite snugly, and I've never noticed a rattle with these pads, unlike the unknown brand ones that certainly did!...
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Re: Wheel Alignment

Tulsaalva said:

I found out the job is best done with two lasers, one in front of the bike and one behind.

I aligned the front laser with the center groove of the front of both tires and the rear laser with the center groove of the rear of both tires. Unfortunately, the beams crossed.

I decided I should do a "rough" alignment first, so I adjusted the pull bolts until I had exactly the same distance between the adjusters and the backs of the rear swinging arm, and three-quarters of an inch of chain play.

I set up the lasers again in the same way as above. When all was done, the front laser was centered in the center grooves of the front of both tires, the rear laser was centered the same on the rear of the tires. To my pleasure, the beams both hit the lenses of their opposites.

The actual adjustment was done by measuring the distance between the adjusters and the rear of the swinging arm, not with the lasers. Although the lasers did confirm the alignment, I have to admit that I spent at least an hour and a half doing a job that should have taken fifteen minutes.

Ah, what the hell? It was fun and that's what fixing these old bikes up is all about, nicht wahr?

Al

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That's an interesting alternative way to do it Al.

But I think I will be sticking with my 65 pence builders line method...for the time being, anyway.

This thread on bonneville tanks has gone bunny trailing to at least 4 other topics.

In a way, that's pretty neat to see, how we all wander in our thoughts.

I'm afraid it's my fault, Grandpaul. I've just used this thread to ask questions as I progress in bringing the bike back to life. Perhaps it'd be a good idea to rename the thread. How about, "Bringing a '79 Bonneville Special Back to Life." How does one rename a thread?

Al