Author Topic: New (to me!) '77 CB400F - US model  (Read 5078 times)

Offline Bryanj

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Re: New (to me!) '77 CB400F - US model
« Reply #210 on: February 05, 2019, 04:56:25 PM »
As you need to keep the adjuster and the cable is scrap a measure of mechanical violence is OK

Online mattsz

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Re: New (to me!) '77 CB400F - US model
« Reply #211 on: February 05, 2019, 05:00:30 PM »
As you need to keep the adjuster and the cable is scrap a measure of mechanical violence is OK

 ;D

Not too much violence needed, cable housing in a vice as you said, and the adjuster "wrenched" right off.  I cleaned it off with a wire brush and I'm soaking it in white vinegar for a day or so to see if it helps it - a small test before I try it inside the fuel tank?

Offline Bryanj

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Re: New (to me!) '77 CB400F - US model
« Reply #212 on: February 05, 2019, 08:47:48 PM »
I have a cable that is longer than those measurements but approx the same "free play" you can have it for postage but that is probably more than a local e bay purchase!

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Re: New (to me!) '77 CB400F - US model
« Reply #213 on: February 05, 2019, 09:05:55 PM »
Thank you Bryan - I don't know how much the shipping would be, but the ebay guy I mentioned earlier has been very helpful with trying to sort out if it's really the right cable, and he's charging US$20 including shipping, so based on all that I'll probably go that way...

Offline Bryanj

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Re: New (to me!) '77 CB400F - US model
« Reply #214 on: February 05, 2019, 09:23:32 PM »
No problem, one of the hazards of living opposite sides of the pond!!

Online mattsz

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Re: New (to me!) '77 CB400F - US model
« Reply #215 on: February 10, 2019, 12:09:50 AM »
So I soaked the clutch adjustment bolt in white distilled vinegar for a few days, along with some fine filing, and it came up pretty neat and clean.  I'll reuse it, with plenty of lubrication/rust prevention.

The clutch lever's pivoted cable mount end is pretty badly rusted where the cable attaches.  I'd like to try to reuse it; can I safely soak it in vinegar as well?  Not sure what kind of finish it has, and whether it will handle it...



Also, where the lever attaches to... umm... whatever it attaches to with that nut (clutch adjusting bolt?)... the lever seemed sort of loose and a bit "floppy?" even though the nut was tight.  Is that normal?

Offline Bryanj

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Re: New (to me!) '77 CB400F - US model
« Reply #216 on: February 10, 2019, 08:36:30 AM »
There is, or rather should be, some "free play" in the lever movement before the mechanism starts to operate the clutch.

Offline Nurse Julie

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Re: New (to me!) '77 CB400F - US model
« Reply #217 on: February 10, 2019, 09:10:53 AM »
These is, or should be, a little anti rattle tube on the lever fitting as well. When these are shot or missing it makes the lever feel even looser.
Edit...him indoors has told me I'm loosing the plot, the anti rattle is on the brake lever...doh  :-\
« Last Edit: February 10, 2019, 09:33:31 AM by Nurse Julie »
Im a Nurse, trust me, this won't hurt.....much !!!

LINK TO MY CB400/4 ENGINE STRIP / ASSESSMENT AND REBUILD...NOW COMPLETE
http://www.sohc.co.uk/index.php/topic,14049.msg112691/topicseen.html#new

Online mattsz

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Re: New (to me!) '77 CB400F - US model
« Reply #218 on: February 10, 2019, 10:17:46 AM »
There is, or rather should be, some "free play" in the lever movement before the mechanism starts to operate the clutch.

I hesitated to refer to the looseness I described as "free play", because the movement I encountered wasn't just in the expected direction of travel.  The cable mount end could be gripped and pulled and pushed in and out a bit - laterally, 90ยบ to the normal "rotational" direction of travel.  I could also hold the other end with two fingers, directly over the mounting nut, and pivot (not rotate) it slightly - basically the same movement just described, but in any direction.  Almost as if the adjustment spindle it was fastened to was made of a stiff rubber material, rather than solid metal?  Yet the locking nut was very tightly fastened... it's difficult for me to describe.  A short video would reveal all, but I'm away from the bike this week.

Would that rubber oil seal behind lever arm allow for such movement?


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Re: New (to me!) '77 CB400F - US model
« Reply #219 on: February 10, 2019, 10:29:36 AM »
These is, or should be, a little anti rattle tube on the lever fitting as well. When these are shot or missing it makes the lever feel even looser.
Edit...him indoors has told me I'm loosing the plot, the anti rattle is on the brake lever...doh  :-\

My parts book calls it simply a "bush" - mine was in place, but in many tiny pieces.  What a pricey little headache!  I bought a replacement for $3.00 (about as cheap as I could find it), as part of an order for a few more items.  If I knew the proper size and composition, I probably could nip down to my local hardware store and find something that would work fine for $3 a meter instead of $3 a centimeter, but that's the way it goes...

Online mattsz

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Re: New (to me!) '77 CB400F - US model
« Reply #220 on: February 11, 2019, 01:07:38 AM »
The clutch lever's pivoted cable mount end is pretty badly rusted where the cable attaches.  I'd like to try to reuse it; can I safely soak it in vinegar as well?  Not sure what kind of finish it has, and whether it will handle it...

Answered my own question...

before, pretty greenish finish:

[ Guests cannot view attachments ]


after soaking the lower half in vinegar:

[ Guests cannot view attachments ]

pretty greenish finish is gone (note the "vinegar-line") and there's a similar greenish rainbow sheen on the surface of the vinegar I'm soaking in.  Hopefully I can just clean it and lube it and it will stay happy...

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Re: New (to me!) '77 CB400F - US model
« Reply #221 on: February 13, 2019, 06:45:35 PM »
Thank you Bryan - I don't know how much the shipping would be, but the ebay guy I mentioned earlier has been very helpful with trying to sort out if it's really the right cable, and he's charging US$20 including shipping, so based on all that I'll probably go that way...

Got the new clutch cable - it's identical in every dimension to the frozen one that came off, so that's a win!  Full marks to the seller who didn't know what he had, but went out of his way to post photos and take measurements to help me decide...

Does this thread belong on the "projects" board?  Does it make sense to keep adding to it here?

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Re: New (to me!) '77 CB400F - US model
« Reply #222 on: March 01, 2019, 06:00:11 PM »
I'm ordering up some brake parts... any way to tell whether my current brake hoses are original?  Should I look for any markings in particular - or lack thereof?  End-to-end, the lower hose is 14", and the upper one is 13-1/2" ('77 US-spec with higher bars).

I'm inclined to re-use them.  They look ok - not what I'd call new, but no cracks or splits or odd bulges anywhere...

Offline hairygit

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Re: New (to me!) '77 CB400F - US model
« Reply #223 on: March 01, 2019, 06:43:56 PM »
Personally I would not use old hoses, you have no idea how old they are, they could be breaking up internally, and let's face it, replacements are relatively cheap, especially compared to wrecking your bike in the event of a sudden hose failure!

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Online mattsz

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Re: New (to me!) '77 CB400F - US model
« Reply #224 on: March 01, 2019, 09:22:56 PM »
Personally I would not use old hoses, you have no idea how old they are, they could be breaking up internally, and let's face it, replacements are relatively cheap, especially compared to wrecking your bike in the event of a sudden hose failure!

Here's where I'm at right now: how many parts do I replace and repairs do I make just to get the bike to the point where I can see if it works?  I want to figure out my baseline before I start dumping money into this project.

That said, however, I'm leaning toward the wisdom of your suggestion - safety should come first!  If the brake hoses were to fail when I needed them, I daresay that damaging the bike wouldn't be my top concern...