78 CB750F2 fork seal replacement: What else while they're apart?

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78 CB750F2 fork seal replacement: What else while they're apart?

Matt Story
Title pretty much says it all.  Have my forks apart to replace the seals.  What else if anything should I look for while I'm in there?  Anything that particularly needs inspection or should be repaired as a matter of habit 'since they're apart'?

Thanks
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

TOOLS1
Administrator
Put in fresh ATF.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

Matt Story
In reply to this post by Matt Story
Any tricks besides prying to get the old seals out?  I have changed fork seal a couple of times before.  I don't remember them being this stubborn.  These have been in for 36 years it seams....  Does it hurt to apply a liberal amount of heat to the tube?  Any particular tools to ease the job?

Thanks
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

TOOLS1
Administrator
A heat gun, or a pan of boiling water works great to heat up the sliders where the fork seals are. This makes them come right out.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

Matt Story
Perfect.  Thanks a lot.
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

Matt Story
So, realizing I didn't have any DexronIII, I dug around the garage and found an old unopened quart of Spectro 10wt fork oil.  How would this compare to the Dexron for ride?  Should I run it or go out and buy a quart of Dexron?  To give an idea how old it is, the price tag is $5.99.  I would guess I bought this in the mid to early 90's.
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

LukeM
Administrator
Having just replaced the fork and dust seals on my VT700C Shadow, I'm thinking the CB750 would be about the same.

To get the seals out, you can use the dental pick approach (pry it out with a good strong metal pick), the heat gun approach (burn the thing out), or use the slider hammer approach (which I used).

You can pull the slider out of the fork repeatedly, and it will gradually pull out the slider bearing and fork seal. Putting back together, look at all the items you remove, and ask youself, "Do I really want to skimp on parts to save some money, or do I want to tear these things apart in a couple of years?"  For me, I put in new slider bearings, new circlips, new backup washers, new fork seals, and new dust seals.  I do not expect to be tearing these forks apart for a while.

I used ATF in my forks.  I didn't use the newest Dexron fluid, but Advance Auto Parts does sell a Dexron type for "older GM and Chrysler transmissions".  You could use the oil you have there, but after 20 years, I would suspect the oil is just too old and thick to use.

Hope this helps.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

TOOLS1
Administrator
Luke, you are NOT burning the seals out. You are just heating them up, so they come out easier.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

TOOLS1
Administrator
In reply to this post by Matt Story
The ATF is rated at 8 weight, so the 10m weight fork oil will work, it just might be a slightly stiffer ride.
TOOLS
Life is not about the number of breaths, you take, but the moments that take your breath away.
I don't have an anger problem. I have an idiot problem. Hank Hill
Never confuse education for intelligence.
Happiness is a belt fed weapon.
I just can't imagine what could go wrong.
No fire? No explosions? So whats the point of your story?
Those who are too smart to engage in politics are punished by being governed by those who are dumber. ~Plato
It couldn't be done, but the darn fool didn't know it, and did it anyway.
We all got problems. Ksharp
I like vintage bikes because they take me away from the clutter of technology that I work with everyday and back to a simpler time of mechanical elegance and simplicity.. "ninadm"
Darkwing Duck: The worst part of public transportation is the Public.
"That is awesome shit there" Re-Run
"Fear nothing, attack everything" Eric Berry
" Oh, you read that on the internet? Clearly it IS a massive problem. Of course it CAN’t be normal operation."

1976 CB 750-A X 2
1977 CB 750-A X 4
1977 CB 750-K
1976 CB 750 F
1981 CB 750
1966 Kawasaki SG 250
1981 KZ 750 LTD
1973 CB 350
1979 CM 185 Twinstar
1982 Honda XL 80
South of Eden (Kansas City MO)
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

LukeM
Administrator
In reply to this post by TOOLS1
Oh, I don't know...sometimes a person would WANT to set part of the bike on fire.

I understand your method, TOOLS. Judicious application of heat can do wonders.
Luke M
Used to have a 1979 CB750L, sold it as a parts bike, now riding a slightly modified 1984 VT700C. Network/Field Engineer. Central OH, USA, Earth, Sol System, Milky Way Galaxy, Universe.
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

Matt Story
In reply to this post by Matt Story
I stood them up in a boiling sauce pan of water for about 3 minutes.  Popped right out.  I likr using boiling water for these kind of operations because you have good control of the heat.

I'm ok with a bit stiffer ride.  Just wondering if the oil is still good.  I'd hate to waste it if its good.  I think Ill try it.  Whats the worst that could happen?
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Re: 78 CB750F2 fork seal replacement: What else while they're apart?

Matt Story
I asked Spectro on their website if the oil would be OK to use.  They said it should be good for "many years" if cappped.  I'm going to go ahead an use it.