Fork leak crush or no?

[gerard]

Hey guys,

Been a long time, but after some health problems and work goofiness and a marriage proposal I am trying to get the bike back on the road.

Anyhow, '78 R100/7

I had to pull the sliders to set the new dual disc one and I cannot get the large nut on the bottom of each to stop leaking. i used copper crush washers and no luck. Torqued to 100 NM. I cleaned the nuts and sliders before placement. I looked in Clymers and they said to not even use the "gaskets" -- just smear some unspecified sealant on the threads and torque away. Any thoughts/opinions?

[SteveD]

Welcome.

Maybe try some white plumbers tape? Is the 100Nm the correct torque?

[wookie]

Noobie here. Just checking; I assume you put the crush washer on the threaded end of the damper rods before you installed the sliders.

[Slashsevenpig]

Post by gerard » Mon Nov 28, 2011 1:42 pm

Anyhow, '78 R100/7

I had to pull the sliders to set the new dual disc one and I cannot get the large nut on the bottom of each to stop leaking. i used copper crush washers and no luck. Torqued to 100 NM. I cleaned the nuts and sliders before placement. I looked in Clymers and they said to not even use the "gaskets" -- just smear some unspecified sealant on the threads and torque away.

Hi Gerard,

Two years ago, I rebuilt the front steering/suspension on my '77 R100/7. Like yours, my slider caps wouldn't stop leaking. I'd like to offer an observation, and my solution.

In my experience as a mechanic, I've noticed over the years that drain plugs of any species, (engine, gearbox, final drive) may look the same in terms of size and color, but the hardness of material itself may be different. Maybe it's less expensive for manufacturers to produce, maybe their stamping dies are getting dull and they produce better-looking washers from the harder stock, or maybe their supplier is using cheaper material. I haven't researched it enough to know for certain.

Here's what I do on all of my machinery (cars, motorcycle, lawn and garden equipment): Clean up the plug really well after removing. Before placing the washer on the drain plug, use a toothpick, q-tip, or another small type of applicator to put a small bead of sealer in the radius of the drain plug where the threads end, and the inner "face" of the plug begins. Don't use too much. or get any on the threads. Place the sealing washer on the plug, and install it. Clean up any excess that gets squeezed out. I use Permatex #2, because it works well, doesn't harden, and is readily available in the U.S.

Of course, the pug will have to be cleaned up and re-sealed at the next removal, but it isn't too difficult. I use a small screwdriver, transmission pick, or similar tool. Once removed, the Permatex kinda' "crumbles" from the plug. I've used this method on all my drain plugs, with no ill effects.

[gerard]

Definately used crush washers on he bottoms of the threaded plug and that isn't leaking. The oil is coming from the large nut that threads into the slider. Clymer says to not even use crush washers there, even though I did use the new copper ones I had in stock. I did clean the threads but used no sealant. Can i reuse the copper crush rings, even though they are crushed already? I just dont feel like waiting or paying $10+ for shipping for the rings but if I must, I must. Has anyone reassembled without using the big crush rings?

[the quinner]

Definately used crush washers on he bottoms of the threaded plug and that isn't leaking. The oil is coming from the large nut that threads into the slider. Clymer says to not even use crush washers there, even though I did use the new copper ones I had in stock. I did clean the threads but used no sealant. Can i reuse the copper crush rings, even though they are crushed already? I just dont feel like waiting or paying $10+ for shipping for the rings but if I must, I must. Has anyone reassembled without using the big crush rings?

I used to always use Hylomar on those threads...along with new crush washers. Now, I don't remove those caps unless I REALLY have to. I use Hylomar on the upper fork cap threads, too.

[Slashsevenpig]

The oil is coming from the large nut that threads into the slider.

Yep, those were the ones that leaked on mine..

Clymer says to not even use crush washers there, even though I did use the new copper ones I had in stock. I did clean the threads but used no sealant. Can i reuse the copper crush rings, even though they are crushed already?

I looked in my Haynes manual, and it said the same thing (don't use the crush washers). I wonder if it might have been a proofreading error. Maybe they meant to say: "Don't re-use the old ones"?

When mine leaked after reassembly, I re-used them, along with Permatex #2 on the threads of the large caps. I haven't had any leaks since. One of the points I was trying to make in my previous post was that those large crush washers seemed to be too hard to "crush," so ordering new ones wouldn't have solved the problem.

it's a mystery to me why those washers are still available, when Haynes and Clymer say not to use them.