RC4 Reservoir, 32mm cone wrench?

[Deerhill]

Anyone know if Park Tool HCW-7 30/32mm Headset Wrench is narrow enough?

[Deerhill]

IFP bleed screw a regular hex like old DHX?

[B$$]

Thought I'd chime in on this as there isn't much info posted on the RC4 yet. Yes, the Park Tool HCW-7 30/32mm Headset Wrench can be used to remove the reservoir cap (I don't see what else could be used) and the IFP bleed screw is a regular hex. I found that placing the shock between two pieces of wood in a vice is needed rather than just clamping the bottom eyelet (the shock body will flex if you do that). There are two points/part of the shock body that are the same width so that clamping with wood blocks works. That's all I got for now. I'm following the DHX Coil rebuild by Nick-M2R.

[Deerhill]

Ah, ended up making my own. Had this apart a few times since, took photos. Will post them when I get home, thanks for the info B$$

[B$$]

That would be great. I had a hard time removing the shaft cap until I put it between the blocks of wood. Any tricks you've learned along the way would be great. I started this due to oil leaking through the shaft seal.

[Deerhill]

Leaking through the dust seal or near the rebound rod?

[B$$]

Through the dust seal and on to the bumper and spring. I'm going to try replacing all the o-rings that see friction and do a bleed. The rebound seemed ok so probably not going to open that up. I did notice that after opening the reservoir and removing the IFP that it was difficult to re-extend the shaft. Don't know if that's normal. I measured my IFP depth at 25mm for an 8.5 x 2.5 shock.

[Deerhill]

These are just some of my notes added to Nick's.. keep in mind, I don't advise anyone do this unless you tune, just send it in for oil change

File #'s changed when uploaded to this site for some reason.. Photos 01-13 here- 12 RC4 in case they don't show up


01 Reservoir needs 32 mm cone wrench (or make vise clamp from aluminum)


02 Release pressure, open BO adjuster. Clamp in vise, turn shock body from right to left to start, unthread by hand


03 Flip cap over, turn both @ same time, don't force threads


04 Measure IFP for general idea (if shock is leaking it's not a "correct reading")


05 Clamp OS stem @ start of threads ( I try not to go over 40 in/lb ) on shock body. Protect the shaft while you crack it open, unthread by hand


06 Use longer screw in bleed port to pull IFP


07 Do the math so IFP doesn't bottom/top out. Write these down... measure chamber depth, measure IFP thickness. Notice where reservoir threads end, be aware of BO adjuster location inside res when knob is full closed (clockwise) position. Make sure you do the math to ensure IFP doesn't bottom or top out, write down depth and any other tuning changes made



08 Bleed/cycle submerged. Seal head threaded a couple turns works. If you hear bubbles, probably a bad thing


09 Main seal should be snugged up, no need to torque yet. Compress


10 Shouldn't see any bubbles on IFP, flip it while submerged


11 Place IFP below top of reservoir


12 Longer screw threaded couple turns allows fluid to pass through bleed port to set depth. Leave fluid on top, close bleed port and cycle. Check proper depth, it may change once it squares up. Remove top fluid, torque everything back together.


13 Don't cycle shock w/o pressure, add 200 psi and leave over night to check for leaks

[B$$]

Good stuff, Deerhill. Thanks. What size shock is that? I saw another post on Ridemonkey where the poster measured the IFP depth at 25mm for an 8.5 x 2.5 shock. Seems shallow compared to other references I've seen but those are for longer stroke shocks. If I was leaking oil wouldn't that result in a deeper IFP measurement?

[Deerhill]

Wouldn't go by someone else's numbers because the shock can have different dimensions (photos are just reference, shaft could be partially extended). Measure when shaft is fully compressed so you can make sure ifp doesn't move near the adjuster, and measure when shaft is fully extended to make sure ifp isn't near the bottom.

If there was oil in the shaft when it was filled, that could leak out and not affect ifp. Would come out near the rebound adj all over the bumper and spring

[B$$]

I did some quick measurements last night and 25mm looks accurate. Into the 30's and I'm at the bottom. I'll definitely do some bench testing. Looks like I should pressurize before testing/cycling the shock. Also, do you find it necessary to submerge the piston and reservoir for the bleed or can if be done the way Nick-M2R does it? Off to the o-ring supplier today.

[Deerhill]

#12 you can cycle it and measure for clearance without pressurizing, like it says just make sure fluid is on top and you close the port to cycle.

I always bleed it like this, never tried the other way. I use old vitamin bottles and tape body for tight fit (look at #09)

[B$$]

OK, this is what I found out at the o-ring place (Rocket Seals in Denver, CO)
Shaft seal - 2-208 B7
Shaft cap housing seal - 2-022 B7
IFP seal - 2-214 B7
Reservoir/boost cap seal - 2-024 B7
These are standard sizes and it looks like the B7 stands for buna, 70 durometer.

[Deerhill]

Cool, did you get o-rings for the hsc/lsc adjusters too? I have not needed to open the boostvalve side or the compression adjusters yet

[B$$]

Everything seems to have gone well. O-rings look to be the right size. Props to Rockets Seals (Rocket Seals). The guy took his time and there was no minimum. I did not open that stuff either. I was just looking into the leaking shaft seal. Everything inside the shock looked good and the old oil was not discolored. I cycled the new oil through a couple of times using the IFP and discovered quite a few air bubbles trapped in the bridge area. So I'm pretty confident I got a good bleed. And, 25mm looks like the correct IFP depth. While I was at it I redid my shock pump too. Thanks for your pointers.

[Deerhill]

Tunability of this thing at 130psi and heavier spring has been really good. Once I start to try softer spring/more psi maybe I'll need to add to the hsc or boostvalve and I'll update the pics, if anyone beats me to it feel free to post up some photos

[B$$]

That's how I've been running it (lower psi and stiffer spring) and it's been great. It's on a Yeti ASR 7 and I've been pretty happy with the setup. Big test tomorrow to see how it holds up. I would have taken pics but I was kind of bumbling along. We didn't discuss oil but I used Silkolene 10 WT, same as my Fox 40 damper. I made an oil bath on the shaft side using a short length in inner tube. Worked pretty well. I run a low budget operation. Gotta use those old tubes for something.

[Deerhill]

Gonna use the tube next for sure, seems faster. Started w/ the like water to flush and been thickening when making changes