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Rear shock sounded and felt fine before if a little sticky - but it hadn't been taken apart and cleaned in ages so I went to do an air sleeve service.
Took it off, cleaned all of the parts. Inspected the o rings (fine) and seals (fine) and split washers (fine).
Oil inside was very dark and dirty so I cleaned that all out. Re-lubed (used 15wt suspension oil), put back together and now it make a very noticeable squelch sound upon initial compression.
Just the first 1mmish of every movement. I haven't actually ridden the bike but it doesn't seem to be impeding the shock in use.
Just the sound cant be good.
I'm pretty sure I've done the same with a different float before - but I've serviced ten or fifteen forks and never had a problem.
My currently un ridden CTD shock does this on initial movement so watching with interest 🙂
It's just the lube in the air can passing through the transfer port (a little nick on the inside of the can that charges the negative air chamber).
So it's my choice of lube (15wt fluid) that's causing the sound? Or did I put too much in? The sound hasn't gone away?
I have the same. It popped up a hundred miles offer a service by Mojo. Can,t stop it and they didn't,t want to know. All seems to work but every pedal stroke squelches.
Open back up .Empty the half a pint of 15wt you put in. 😀
Does it still make the noise.If not put a wee bit of float fluid in next time.. 😉
You only need a small amount.
at 7.00mins
Took it apart, emptied out the 2-3cc of 15wt, reassembled, and it still squelches on the first few mm.
It's fine when the shock has no pressure in it, but as soon as I put a few psi in it and start to cycle the suspension... "psssht. Pshhht".
Don't have any float fluid as I take offence at spending £10 for a tiny sachet of blue fox piss.
Maybe I'll try 80w gear oil.
Float fluid is 80wt or 85wt gear oil, so that sounds ideal. The squelch is just some oil moving through the port hole and is nothing to worry about. As the piston seal moves the first 2-3mm it passes the equalizing port and air and oil move through by design, only way to prevent the noise would be to have no oil lubricating the piston seal and that's not going to end well.
With 'no air in' there is likely insufficient pressure to move the oil out of the way/through the port during your cycle test. So that should be why you can't hear the noise.
Also in case you think it should stop over time, it won't (unless the oil blows out the shock). As you start to compress the air pressure rises in the positive and falls in the negative, as the piston seal hasn't yet passed over the equalizing port the air flows along with some oil though the port to maintain equal pressure. Then the seal passes over the port and no more air and oil can flow. On extending towards uncompressed the seal passes back over the port opening the port. At this instant the pressures are equal, but as the shock extends to full length the pressure rises slightly in the negative chamber and air and oil flow through the port to maintain equal pressures. (equal pressures, so why does it extend? Well nitrogen charge in the damper, momentum, weight of undamped mass).