Topic: front forks

[mongeon]

I can't get my front forks off.  I need to replace the fork seals.  It may just be rusted in, but I can't seem to find a good point to pull on to get any force.

If possible, I would like to leave them in place.  Is this possible?  I have tried to unscrew the hex bolt on the bottom, but I am in grave danger of stripping them.  It may be easier if I can get the forks off, but I don't have a vice even if I do.  I realize stuck bolts is a general problem, not specific to forks, but the spinning fork adds a new level of difficulty.  Any help would be greatly appreciated.

Oh, and its a 74 550k

thanks
chris

[mongeon]

I used a little more muscle and got the forks off.  Still can't loosen the bolts.

[mgilvary]

A good way to get the forks off of the bike is to tap on the top of the fork tubes (on the bolts) using a rubber mallet, or a wooden dowel and a hammer. The forks on these bikes seem to be very prone to rusting between the clamps, so I'm sure that's the problem you're having.

[MetalHead550]

So are the damper bolts on the bottom not moving at all, or are they causing the tube to rotate within the lower fork case as you try to loosen it?  As you know, that bottom bolt is what holds the tube in the lower case and I remember having to pull the tube till it was fully extended and then pulling it that way with some force so that the bolt would loosen without spinning the tube.  Make sense?  A tip for putting the new seals in is to put the tubes in the lower case then slide the new seal over it till it sits on its lip in the lower case.  Then use a two foot lenth of 1 1/2 inch pvc pipe to press/carefully pound it till its fully seated.  Youll need to file or sand the outer edge of the pvc a bit though cuz its a tight fit otherwise.  Worked great for me though.  Good luck.

[mongeon]

not spinning at all.  It's soaking in wd40 right now, so maybe in the morning.

[oldbiker]

If you don't have an air impact wrench youself, could you not take the whole tubes into your local shop and ask them to loosen the screws with theirs.

[TwoTired]

There is a part inside the forks that the end bolt screws in to.  The only thing keeping it from spinning is the tighteness of the end bolt, and the pressure from the springs in the fork tube.

If you don't have inertia to work for you, as an impact (air) tool would provide, reassmbling the forks with the spring preload may also allow you to loosen/remove the end bolt.  Once the bolt is loose, remove the spring preload.

[mongeon]

Got it disassembled, with the help of the amazing impact driver.  Now I can't get the oil seals out.  Any suggestions?

[TwoTired]

You have to remove the snap rings.

[mongeon]

I removed one, from the top.  I think that is the only one.  there is a lot of corrosion, which may be making things worse.  I cant get a grip on the seal, and don't want to pound away to much with a screwdriver for fear of gouging the metal around the seal.

[TwoTired]

You need a pry bar.  Or, (shudder) a very large screwdriver.  Pry under the lip of the seal across the fork mouth.  Lay a stiff folded rag or some other type of pad on the fork to protect the soft aluminum from the pry bar.  You want the prybar tip to lift the shoulder of the seal without gouging the fork seal seat in the fork tube with the tip into the soft aluminum. Pry it up a little and repostion around the circumference of the seal to slowly walk out the old seal.

[mongeon]

Got it!  Not without a little blood.  New problem.  According to my manual, there is a part called an Oil lock.  I have not seen any such part.  It seems too big for me to have lost, and I don't think I would have lost both.  Is it possible that the manual is wrong, or that the forks are somewhat different between 550s and 400s (mine is 550)?

Please help, I am so close!

[TwoTired]

What manual and page number?

[mongeon]

Haynes, page 80.  Also what is the 'correct quantity of fork oil'?

[mongeon]

think I found it.  Does it go in the bottom of the fork slider?

[TwoTired]

The oil lock is the part that bolt 12 screws through.  It may have come out with the tube, or is still at the bottom of the fork lower inside.

Fork capacity 185-191cc or 6.3-6.5 oz.  In the Honda shop manual, listed page 137.

It appears the Haynes is wrong on page 9.  Those capacities apply to the CB500 forks, according to the Honda shop manual.

[mongeon]

Now my front brakes are crazy tight.  I had to loosen the two bolts that hold it together to get the wheel back on, and I can't tighten it all the way back because the pads are squeezed so tight together.  What the hell happened?

[TwoTired]

You probably bumped the hand brake. This pushes the caliper piston out.  You should be able to push it back in.
If you push it in way too far the master cylinder will over flow.  That would be bad.
If the caliper is in position against the rotor just take the plam of your hand and push the caliper into the rotor.  You might have to push pretty hard. This should retract the piston so you can reassemble the caliper halves.
After assembly, you might have to pump the lever a time or two to get things right again.

[mongeon]

should the outside brake pad be sitting loose?  Or is there some sort of pin to keep it in place?

I think the piston did come out, but I can't get it back in.  I will keep trying.  Thanks.

[TwoTired]

The stationary pad is free to float, and is retained by a cotter pins. 

If the piston came out there will be a loss of brake fluid and rather a mess.  It's probably best to clean and rebuild the caliper if this occurs.  Remnants of brake fluid on the wrong side of the seal will shorten the life of the caliper and degrade the pad.

See:
http://sohc4.us/node/50