FORK OIL CHANGE

[RC42]

Hi all
I have a 1995 cb750 rc42, i want to change the front fork oil but not done this before. not sure how much i need and is it as simple as undoing top nut and undoing drain bolt at base of leg ? any help would be gratefully appreciated.

andy

[TOOLS1]

Welcome to the forum Andy.
Yes changing fork oil is that easy. Unfortunately I do not know how much your bike holds. I know the 69-78  hold 5.5 oz of ATF. I am sure your locale Honda dealer will be able to tell you, or there might be a downloadable manual in our manual section here. Also if you have never changed fork oil before. You will be surprised how bad it will look, and smell. that stuff takes a beating. I change mine every year.
TOOLS

[sgtslag]

Sorry, I don't know the amount, either.  However, after removing the drain plug, and top cap, be sure to pump the forks up/down, to expel all of the old fluid.  BE CAREFUL!!!  Once you remove the top caps, there is nothing holding up the front end!...

If you want to really clean the insides out, pull the top caps, one at a time, and pour in 2 oz. of SeaFoam*, then replace the top cap.  Bounce the front end up/down several times, then pull the drain plugs, and the top caps.  SeaFoam* will dissolve any sludge within the forks, and it will slightly thin the fluid.  This will ensure that you get all of the crud out of the tubes that is possible to remove, without complete disassembly, and using a parts cleaner.  Cheers!

*:  SeaFoam is available everywhere, but Wal-Mart seems to be among the lowest priced.  It is a multi-use solution.  Be sure to read the label for directions, although this is a slightly non-standard application.  It will NOT harm any seals, or parts within.

[RC42]

Hi
Nice one, thankyou. I'll try a dealer.

[RC42]

Hi
Nice one some good tips there, i know the springs will pop up so i need to control the top nut on release but hadn't thought about the bike being held up !! thanks.

[TOOLS1]

Just do one at a time, and you will not have to jack up the front end. Also when you remove the top cap's the springs only move about an inch, so don't be afraid of them flying across the room.
TOOLS

[TOOLS1]

Here you go.

Suspension
Front fork oil capacity 482cm³
Front fork oil type 110
Front suspension free spring length 28cm (10.7 inch)
Rear suspension damper medium Compressed Nitrogen Gas
Rear suspension free spring length 253mm (10 inch)

TOOLS

[maverickfhs]

Sorry for bumping this old thread, but I am planning to replace a fork seal, as well as oil. Is there a drain plug for 1992 NH 750 too?

Also, should I replace the bushing too or no need for it?

[TOOLS1]

There should be a drain screw/bolt on the lower part of the fork to drain the oil out of. As for the bushings, I have never seen any worn out bushings. However I have seen damaged bushings from people improperly installing them.
TOOLS

[maverickfhs]

Thanks very much, I appreciate it :)

Are you talking about the hex bolt, which uses an impact to be removed at the bottom center kind of area?

Would you think I can use these ones? http://www.ebay.com/itm/321808830075?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

Also, I am planning to remove the fork tubes, one by one and then slide the dust seal upwards and then try to shred the old seal. Then will open the forks from top, take the old fluid out and will slide the new seal in place.

Is this method going to work or no? Thanks for the help.

[TOOLS1]

I do not know what size seal your bike uses, so can't say on the seals. They do seem pretty cheap though, and that should be telling you something. The drain screw/bolt is usually on the outside of the fork slider on the side near the bottom. You might be able to remove the seal without disassembling the fork, but if you are able to accomplish this your next move should be to buy a lottery ticket. I would remove the bolt on the bottom that holds the slider onto the tube, and the clip at the top over the seal, remove the tube from the slider (the seal should come out with it). Then reinsert the tube into the slider, and then install the seal over the tube.
TOOLS

[maverickfhs]

Thanks, I guess then I should not waste time trying to shred the seal then?

Any thoughts on these two:

http://www.ebay.com/itm/Fork-Suspension-Seals-41x54x11-Honda-Kawasaki-Suzuki-Yamaha-Motorcycles-/151846858488?hash=item235ac72ef8:g:psIAAOSw~bFWHCFH

http://www.ebay.com/itm/151846846616?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[TOOLS1]

K&L products have a good reputation.
TOOLS

[Re-run]

Well, I figure it can't be too difficult. First, leave everything in place. Remove the drain screw and drain the oil out. Jack up the front and brace it. Then remove the top and take the spring out. Remove the tube from the tree then. Now, I prefer to clamp the lower in a vice. I put wood on each side to protect it, then clamp it down. Remove the center bolt from the lower and then you can pull the tube out. This wwill remove the oil and dust seal.

Now, I did my Magna forks like this. The biggest issue was getting ALL corrosion or build up off the bushings, or they won't go back in easily if at all. For the seals, I used All-Balls. They seem good and are commonly used for steering bearings and wheel bearings. Biggest thing is to drive the bushings and seals in properly. Lube them before putting them in, also. My magna forks are probably the same size as yours and I used a 1.5 inch I.D. pvc tube to drive them in straight.

You did get the manual here, right?

[maverickfhs]

Thanks TOOLS, I'll get K&L then.

Re-run, I do have a honda service manual. If there are any other manuals, can you please point me to them?

For removing the drain screw, should I use an impact or regular hand tools?

Mind sharing length of PVC pipe? Like 6" or 12" ?

[Re-run]

For the drain screw on the side of the leg, a regular tool will be fine. The screw on the bottom that holds the leg together, use an impact.

Length should be long enough to go over the upper as you'' use it to pound on to drive the seal in. So, if the upper is 12 inches, then at least 14 for the pvc.

The honda manual is the best you'll find.

[maverickfhs]

Thanks Re-run and makes sense :)