XRAY - Model racing cars

What is your method on building and bleeding the XB8 shocks?
When you bleed the shocks where do you have the shock shaft, all the way out, half the way in.................?
I built my shocks and I oppend them to see if everything is ok, but I saw that there are air bubbles in it, and also the shock blater of 2 shocks where pushed in.
The way I did them is fill the half the way with oil, move the piston slow up and down so the bubbles will escape, leave them for some time so all the bubbles escape from the oil, fill the rest of the shock with oil, screw the cup on the shock, press the shock shaft 3/4 in, put the shock in 45 degree angle with the small hole facing upward and screw the shock body on the cup while holding the shock shaft steady at 3/4 in.
Am I doing something wrong?

1,Extend the shaft all the way to the bottom of the body.

2, Fill with oil to about 1/4" 1/2" from the top.

3,let the filling bubbles rise and pop.

4,slowly push the shaft up letting the oil backfill in around the piston, to fast on the up stroke and you will whip massive amounts of bubbles in the oil. dont raise the piston out of the oil, keep it submerged.

5,Once you have completed the down stroke, let the shock sit for a bit.

6, Repeat #4 again. (I usually do this about 4 times to get all the bubbles out).

7, All shock shafts should be positined at the down stroke once you are done with step 4

8, Make sure the cap bladder is seated in the shock cap properly, wet the bladder with a couple drops of shock oil.

9, Now top the shock off till you see the surface tension of the oil slightly pushing the oil up above the shock body (but not spilling over, if you can help it).

10, have a rag handy for the next few steps,,,LOL.

11, very carefully lay the cap on the top of the body and thread on till you start to see the shock body thru the bleeder hole on the cap, do not tighten down the cap all the way.

12, With the bleeder hole stightly oozing oil from capping, start moving the shock shaft up very slowly allowing the oil to esape out the bleeder hole, GO SLOW on the up stroke.

13, Complete the up stroke with the shaft all the way up against the shock rod end.

14, Allow the oil to esape for a few seconds out the bleeder hole before tightening down the cap.

15, Tighten down the cap using good judgement, dont overtighten or you stand the chance of cutting the cap bladder. (check for burrs on the top of the shock body where the body hits the shock cap bladder, if by chance you find any, sand the tops of the bodys flat with some 4000 grit sandpaper)

If I missed a step or someone has an addition to this please chime in.

Hope this helps Silo.

Keith

I noticed that the when the shock shaft of the front shocks are completely compresed, piston is touching the bladder, Is this ok? Doesnt it affect the shock performance?

My apologies, slightly smoothen the edges of the piston with a fine coarse sandpaper, test it on the shock body to see if it just has enough room to slide freely without binding; till you feel a smooth movement of the piston going up and down.

i wonder if it was possible, to place a small o-ring on the bottom of the piston inside the shock body, to protect it from warping during sudden droop?

it could be revolutionary! LoL

Here's how I build mine:

First, I leave the shock shaft fully extended and fill 90% of the body with oil.

Second, slowly work the shaft up and down while being careful not to break the surface of the oil and create more bubbles. Fully extend the shaft and allow the oil to rest for a few minutes to get rid of the air bubbles. After the bubbles are gone, fill the shock up until you see the surface tension.

Third, I slowly push the shock shaft about half-way through the stroke (while being careful not to push the oil out of the body). I place the cap on and turn it once. Pull the shock shaft down and then screw the cap the rest of the way on. Oil will leak from the bleed hole.

Lastly, you will find a lot of rebound in the shock. Adjust it to your liking by slowly unscrewing the cap until a small amount of oil leaks from the bleed hole. Tighten it up again and feel the stroke to see if it's what you want. Do it a little at a time to get the shock to your liking.

Hope it helps .

You are going to have air in the oil after pushing the shafts up and down.

These are a air/oil emulsion shocks. they are just a oil filled dampner, not a nitrogen gas charged shock like you would find on a full size vehicle. (the nitrogen in a full size pops the bubbles that form and also cools the oil.)


during the bleeding process you are just trying to get rid of the large quantities of trapped air and excessive oil so you dont have Automatic rebound or compression, Like Ajoiner explained on his last paragraph of his post.


If you rebuild a shock and have it sitting there on the worktable,, you then pick it up and run the shaft up and down, several times real fast, then uncap it,, you are going to find a bunch of air bubbles in the oil.

Tru dat

another thing i do is when i put the cap on about one thread i make sure the bleed hole is facing up and then i screw the body onto the cap.

no dont cover the hole let it breath.