'78 cb550 fork seal?

You call McGuire Bearing here in Portland, and see if they have it? Just give them the numbers off the other one you got.

 

hit up vicous cycle on interstate, they guys have had every little gasket i've needed so far.

 

if it is the high pressure seal you might try Seal Source out off of Airport Way.
when i worked at mcguire, we didn't stock many in a high pressure/cylinder type seal.

 

Really? I've gotten them there before.


Interesting to know, and thanks for the other name to add in the book. Few people know to look there first and why.

 

+1

never heard of them.

 

Dare I say Dr. Browns? That old grouch should have some for ya.

 

Yeah, ~somewhere~. crackup:

But he probably does!!!
(sorry Sax, just a joke)

 

On second thought, since when are fork seals considered 'high pressure'???

All the years I've shopped there, I thought that comment didn't make sense.

 

when i had to redo the forks on my older Yamaha, McGuire didn't have the "style" of seal used.(it looked like one in a hydraulic cylinder-which have different psi ratings) now please correct me if I'm wrong, but i think a fork is similar to a cylinder in design( rod, barrel, piston check valves etc)
so while not being "high" pressure they are higher than a normal application for a seal you might find in a gearbox or something.
i matched up the outermost seal, it being more of a wiper in it's function. now granted that was a while back and i haven't worked there since 2003. a lot changes.
and i don't know what the style of the Honda fork seal is.
the years and the bourbon make the mind fuzzy....

 

Fork seals on a '78 are NOT high pressure. You should replace both sides at the sametime. Along with the 'dust seals' on top.
Why change both at the sametime?
Because you have to remove the front wheel and fork to do one. Why not while your there and already have the bike apart do both?
Besides, usually if one goes the other isnt too far behind.
The HIGHT pressure seals MAY have a second or third seal lip. This is good for heavy equipment. But, it may not be so good on a lite weight motorcycle.
The extra seal lip may cause stiction. (drag)
If you can, stick with HONDA seals. They work. The after market stuff, not so well.
18 years as a Honda parts guy.

 

I think the bikemaster seals are basically OEM; they're Japanese-made. I just put a set of their oil and dust seals on the USD fork on my Bandit and they've held up great. Admittedly it's only been about 3 months since I installed them but I ride in real gritty conditions and no signs of any leaks... yet. You need to be real careful when installing the new seals as the inner stanchion tubes have a sharp enough edge to damage the oil seals while installing them. More of an issue on a USD fork because they tend to piss oil all over the place with the slightest leak in the oil seals. I wrapped the end of the inner stanchion with saran wrap then slid the seal onto it (dust seal first, then the oil seal). Then I clamped to halves of 2" PVC pipe to the stanchion with a hose clamp and used the hold thing as a slide hammer to press the oil seal into the outer fork tube (DO NOT try working it in there with a screw driver). They make special slide hammer tools but this is way cheaper and works great. Just be glad you don't have to fab up a spring compressor to get the spring off the damper rod, biggest PITA of working on a USD fork.

Have you checked the bushings for wear? This is the best time to replace them if they have any scoring. Also check the stanchions carefully for any scratched or scoring. I had to clean mine up a little and wet-sanded them very carefully with some 600 grit sandpaper. If you can feel the scratch with your fingernail, chances are it will slowly rip away at the new oil seal and cause another leak somewhere down the road.

 

i'll apologize and recant my use of the term "high pressure". i told you bourbon makes the brain fuzzy
i got to work this morning and was going through one of the seal books we have and see that most standard seals are good for low pressure then the next jump is medium pressure.
those ratings are based on the shaft spinning. the faster it spins the lesser the psi it can take. since the rod(shaft) of the fork does NOT rotate, then the pressure rating would be at the greatest value for that seal design. so i stand corrected. sorry my verbiage caused any confusion.

 

No problem. Between McGuires and Seal Source, people should know that they both sell most bearings and seals found on your bikes cheaper than the dealerships. And in many cases better quality or the option for upgrade.

 

It will have bushings of one kind or another in there, that's the only structural interface between the inner and outer tubes. If it's anything like a modern fork each tube will have it's own bushing for a total of four. They usually have some kind of hard teflon coating that scratches easily if a piece of road grit gets past the oil seal. The inner stanchion will usually have corresponding scratches. If there are any visible gouges on the surface of the inner stanchions, the bushings pressed into the outer tubes probably need to be replaced. Like the oil seals, they can be easily damaged when installing new ones so take your time as they run about 10-15 bucks a pop.

 

They might just be integral with the out tubes, I think that's more common on these older bikes. Once they develop slop, you replace the whole fork I guess. :scratchea You'll have to ask one of the old fossils on here as this bike was made before I was born and I have no idea crackup: