Rear shock oil change?

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Rear shock oil change?

Postby rbates9 » 03:52 pm Mar 29 2013

I am looking to change the oil in my shock this weekend and I am just looking for tips and what NEEDS to be replaced every time the shock comes apart.

I looked thru the book and it doesn't look too bad to do. Pretty much just clean up the bores before you drag the seal head and bladder past the snap ring groves.

Anything else I'm missing?
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Re: Rear shock oil change?

Postby Jason » 08:52 pm Mar 29 2013

If it has a lot of hours on it:

bottom out bumper
bladder
seal head
shaft nut
piston band
o-ring under piston band

If you feel real froggy, bleed bolt o-ring, reservoir circlip and body circlip

Measure compressed shock spring length before loosening lock collar, so you can reset to correct sag level.

Shove grease down into the hollow shaft before grinding the peening off the nut. No need for shavings to get inside. :naughty:

If you use a bench grinder, take small bites, don't sit and wail on it for a long time.

Red Loc-tite (25 ft-pounds) on the NEW nut.

Surface sand both sides of the piston lightly on 320 sandpaper on glass (or if you are lucky enough to have a surface plate.

Use LOTS of brake cleaner.

Use a piece of wire to put all the shims and piston on when you take it off the shaft. Check for any cracked shims.

Good luck!
Thank you, Julien D for all your hard work!

PLEASE! Do not "dip" PWK Keihin carbs in Berryman's to clean them! It will damage the internal o-ring (jet block gasket).
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Re: Rear shock oil change?

Postby KDXrider1989 » 09:35 pm Jun 21 2013

Jason wrote:Shove grease down into the hollow shaft before grinding the peening off the nut. No need for shavings to get inside. :naughty:

If you use a bench grinder, take small bites, don't sit and wail on it for a long time.

Red Loc-tite (25 ft-pounds) on the NEW nut.

Surface sand both sides of the piston lightly on 320 sandpaper on glass (or if you are lucky enough to have a surface plate.




Im rebuilding my rear shock right now as well. The seal doesn't leak, but the shock probably hasn't been apart in over 20 years and I figured since Im already in there I might as well replace it, I gotta install a new bumper anyway. Im kinda stumped on grinding off the peening, its okay to grind off all that metal to where its level with the nut? and what do you mean by sanding down the piston on glass?
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Re: Rear shock oil change?

Postby Jason » 11:16 pm Jun 21 2013

KDXrider1989 wrote:
Jason wrote:Shove grease down into the hollow shaft before grinding the peening off the nut. No need for shavings to get inside. :naughty:

If you use a bench grinder, take small bites, don't sit and wail on it for a long time.

Red Loc-tite (25 ft-pounds) on the NEW nut.

Surface sand both sides of the piston lightly on 320 sandpaper on glass (or if you are lucky enough to have a surface plate.




Im rebuilding my rear shock right now as well. The seal doesn't leak, but the shock probably hasn't been apart in over 20 years and I figured since Im already in there I might as well replace it, I gotta install a new bumper anyway. Im kinda stumped on grinding off the peening, its okay to grind off all that metal to where its level with the nut? and what do you mean by sanding down the piston on glass?


WOW! That must be some fine smelling oil!

If you can, post a picture of the bladder, please.

http://www.racetech.com/page/id/138

YEAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHHHHHHHHHHHH!!!!!!!!!!!!!!!!!!!! :rock: :rock: :rock:

I need to post the links for everyone.
Thank you, Julien D for all your hard work!

PLEASE! Do not "dip" PWK Keihin carbs in Berryman's to clean them! It will damage the internal o-ring (jet block gasket).
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Re: Rear shock oil change?

Postby KDXrider1989 » 11:39 pm Jun 21 2013

You guessed right, and that oil was BLACK! even better, when I drained out the old oil it rushed out after I pumped the shock, and it hit the corner of the oil pan just right to splash up and onto my face. guess I shoulda worn a face shield :kick:

very helpful link you got there, I looked at this one: http://dirthammers.com/wp-content/uploa ... ervice.pdf
of course the KDX oil specs are gonna slightly differ, but everything else is almost the same
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Re: Rear shock oil change?

Postby KDXrider1989 » 11:47 pm Jun 21 2013

can the KDX shock rod peening be completely grinded down?
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Re: Rear shock oil change?

Postby Jason » 07:22 am Jun 22 2013

Yes, use some paper towels or rag during disassembly. I ruined two shirts before figuring it out.

Yes, just shove some grease in there and slowly grind it flat. Watch the second shock video.
Thank you, Julien D for all your hard work!

PLEASE! Do not "dip" PWK Keihin carbs in Berryman's to clean them! It will damage the internal o-ring (jet block gasket).
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Re: Rear shock oil change?

Postby KDXrider1989 » 11:35 am Jun 25 2013

trying to bleed out the air now, no oil is coming out of the air bleed screw after filling both the reservoir and shock body to the recommended levels. added more oil into the hole and pumped the shock a few times and still no oil coming out. what do I do now? I followed the exact directions from my manual
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Re: Rear shock oil change?

Postby Jason » 04:10 pm Jun 25 2013

Is the oil level at the bolt hole?
Thank you, Julien D for all your hard work!

PLEASE! Do not "dip" PWK Keihin carbs in Berryman's to clean them! It will damage the internal o-ring (jet block gasket).
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Re: Rear shock oil change?

Postby KDXrider1989 » 07:37 pm Jun 25 2013

I ended up taping a cut open soda can and submerged the top of the shock in fork oil, pumped it a few times and screwed in the bleeder bolt while submerged and let it sit for a few minutes. when I went to open it again the oil is at the very bottom of the threads, so I guess Im okay. If I were to fill both sides more than the recommended levels, wouldn't that make it easier since itll just pour out of he bleeder hole?
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Re: Rear shock oil change?

Postby Jason » 10:42 pm Jun 25 2013

Are you pumping the shock, in an upright position, then letting it set for a few minutes, then removing the bolt??

When the bladder is installed, the excess in the reservoir runs out over the edge.
Thank you, Julien D for all your hard work!

PLEASE! Do not "dip" PWK Keihin carbs in Berryman's to clean them! It will damage the internal o-ring (jet block gasket).
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Re: Rear shock oil change?

Postby KDXrider1989 » 11:16 pm Jun 25 2013

yep thats what I did, got the shock injected with nitrogen and no leaks anywhere from the looks of it. the shop I took it to could only get it up to 120 psi, Ill have to take it to a motorcycle shop / dealership tomorrow
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Re: Rear shock oil change?

Postby Jason » 12:43 am Jun 26 2013

Sounds good. 150 on the psi.
Thank you, Julien D for all your hard work!

PLEASE! Do not "dip" PWK Keihin carbs in Berryman's to clean them! It will damage the internal o-ring (jet block gasket).
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Re: Rear shock oil change?

Postby KDXrider1989 » 03:04 pm Jun 26 2013

I put 170, thats what the manual says is stock setting
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Re: Rear shock oil change?

Postby Jason » 07:33 pm Jun 26 2013

Hmm. I thought 142 was stock.
Thank you, Julien D for all your hard work!

PLEASE! Do not "dip" PWK Keihin carbs in Berryman's to clean them! It will damage the internal o-ring (jet block gasket).
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