'85 Fork Seals, looking for, if memory serves, David R's homemade tool inst.

[JoBrCo]

Does that DWV PVC have enough mass?
It might be better to keep it long, more mass.

Plus I don't know about yours, but my wife said she likes mine real long.

FJ's Forever

JoBrCo

The mass comes from the hammer that drives it... nuff said... 

[movenon]

Don't over think it.
George

I'm just saying that I fully understand your concern of pits on the tube, effectively resulting in the machining action of the seals sealing lip, thus causing early failure.  I was agreeing with you George, while at the same time sharing your concern, as it's one of mine.  So will I be able to see pits where I don't want pits, using your method?  I wasn't being rhetorical, I really wanted your thoughts on the matter.

The pit I had you could see and feel. Looked like a rock had it it. From memory 1/16inch on diameter.  And was located dead center in the front of the tube in the middle of the usable area of the suspension.

Worn fork bushing can also contribute to seals not holding. Or could be as simple as this. https://www.youtube.com/watch?v=1owBoyM-i3k RPM stocks them or you can make your own.  https://www.youtube.com/watch?v=nEzjdFQp6IM

[Bones]

Before you put the new seals in, give the stanchions a linish with some very fine wet and dry sandpaper and wd40. Clamp the fork in a vice, cut the sandpaper into strips, spray the stanchion with wd40 and wrap the strip of paper around the stanchion as many times as length allows and pull back and forward while going up and down the leg. It'll smooth out any little nicks etc. Doing that and using good quality seals should ensure a long life between changes.

[racerrad8]

See my OP, I bought the ones I have from you, but then I believe I understand marketing, though I'm no salesman, you?  
JoBrCo

JoBrCo,

You are correct, I did glaze over the OP and missed the fact you had already purchased the RPM FJ 41mm Fork Seal & Wiper Kit.

Randy - RPM

[JoBrCo]

Before you put the new seals in, give the stanchions a linish with some very fine wet and dry sandpaper and wd40. Clamp the fork in a vice, cut the sandpaper into strips, spray the stanchion with wd40 and wrap the strip of paper around the stanchion as many times as length allows and pull back and forward while going up and down the leg. It'll smooth out any little nicks etc. Doing that and using good quality seals should ensure a long life between changes.

This post begs the question:  What are the "inner" tubes made from?  What I mean to ask is, are they made of a base metal such as regular steel, that's chrome plated, or are they some sort of "solid" alloy, that stays shiny and corrosion resistant, no matter how much material you take off?  I've always assumed they were chrome plated base metal, that can't sustain a very deep pit without further corrosion taking place at a more rapid rate, and thus more abrasive to the seals.  So personally I'd be afraid to take 800 grit W/D to them.



Anyone know?


FJ's Forever   


JoBrCo 

[JoBrCo]

See my OP, I bought the ones I have from you, but then I believe I understand marketing, though I'm no salesman, you?  
JoBrCo

JoBrCo,

You are correct, I did glaze over the OP and missed the fact you had already purchased the RPM FJ 41mm Fork Seal & Wiper Kit.

Randy - RPM

Right... 

By the way, last year, when I talked to you about the float needle valves leaking, I found out that I had unknowingly slightly bent one of the float hinge pins, and it would randomly get hung up, causing the fuel overflow. 

So I painstakingly bent it straight and sanded it a bit as a temporary measure, I need to get four of those pins some day. 

FJ's Forever   



JoBrCo

[fj1289]

Before you put the new seals in, give the stanchions a linish with some very fine wet and dry sandpaper and wd40. Clamp the fork in a vice, cut the sandpaper into strips, spray the stanchion with wd40 and wrap the strip of paper around the stanchion as many times as length allows and pull back and forward while going up and down the leg. It'll smooth out any little nicks etc. Doing that and using good quality seals should ensure a long life between changes.

This post begs the question:  What are the "inner" tubes made from?  What I mean to ask is, are they made of a base metal such as regular steel, that's chrome plated, or are they some sort of "solid" alloy, that stays shiny and corrosion resistant, no matter how much material you take off?  I've always assumed they were chrome plated base metal, that can't sustain a very deep pit without further corrosion taking place at a more rapid rate, and thus more abrasive to the seals.  So personally I'd be afraid to take 800 grit W/D to them.



Anyone know?


FJ's Forever   


JoBrCo 

Older ones are steel tubes with hard chrome plating.  Newer models have some different "low friction" coatings - but I don't know if they are applied directly to the base layer or over something like hard chrome. 

[Bones]

The tip about linishing the stanchions came from an Australian motorcycle magazine called Motorcycle Trader.  I did my stanchions this way a couple of years ago and have had no problems after doing it. I put new seals in when I fitted RPM valves and new bushes recently, but didn't really need them, the old ones were still in good condition and leak free.


http://www.trademotorcycles.com.au/spannerman-tech-advice/1312/advice-how-to-replace-fork-seals/

[CutterBill]

FYI... fork tubes are hard-chrome plated, then ground to size.  If you find that your fork tubes are badly nicked or scored, don't throw them away.  They can be re-chromed.  I do this to airplane landing gear struts all the time.  It's no big deal and not terribly expensive.

[FJmonkey]

FYI... fork tubes are hard-chrome plated, then ground to size.  If you find that your fork tubes are badly nicked or scored, don't throw them away.  They can be re-chromed.  I do this to airplane landing gear struts all the time.  It's no big deal and not terribly expensive.

That is a great idea, thanks.

[JoBrCo]

The tip about linishing the stanchions came from an Australian motorcycle magazine called Motorcycle Trader.  I did my stanchions this way a couple of years ago and have had no problems after doing it. I put new seals in when I fitted RPM valves and new bushes recently, but didn't really need them, the old ones were still in good condition and leak free.


http://www.trademotorcycles.com.au/spannerman-tech-advice/1312/advice-how-to-replace-fork-seals/

Hey Bones, what grit did you use? 1200?

Quite some time ago I couldn't find anything above 600 grit, but today I see much finer.  What would be the minimum grit to be considered a polishing grit?  What about either "Polishing Compound" or "Rubbing Compound?"

[JoBrCo]

FYI... fork tubes are hard-chrome plated, then ground to size.  If you find that your fork tubes are badly nicked or scored, don't throw them away.  They can be re-chromed.  I do this to airplane landing gear struts all the time.  It's no big deal and not terribly expensive.

Landing gear struts...  ...Now that's something I'm familiar with, at least those on a Lockheed P3C.

Though expensive is relative, and I'd say that anyone that owns an aircraft, can relatively afford to re-chrome their struts. I mean, how much do brand new struts cost anyway?

How much would you suppose it'd cost for both fork tubes to be "hard-chrome" (heat treated or chrome alloy?) plated?


FJ's Forever!   


JoBrCo

[CutterBill]

...Though expensive is relative, and I'd say that anyone that owns an aircraft, can relatively afford to re-chrome their struts. I mean, how much do brand new struts cost anyway?

For a Cessna 310... $5000.  Each.  Last time I had them rechromed (for a customer) it was $1100 for all three.  But that's airplane stuff... 

To rechrome motorcycle fork tubes, I would guess $200-300 for both.  But I could be wrong...
Bill