On 27/10/2020 21:38, T i m wrote:
On Tue, 27 Oct 2020 20:55:41 +0000, newshound
wrote:

snip

OOI, does that mean that I could use 'any' oil that complied to ISO22
(average viscosity 22 @ 40DegC etc) or is that just an umbrella term
(because of the additives I believe you have mentioned previously)?


It's a highly refined mineral oil, so not likely to have a particularly
good viscosity index (this is a measure of how rapidly viscosity changes
with temperature).

Ok.

ISO 22 just tells you about its viscosity. Most hydraulic oils seem to
use Group II base oils (refined mineral oils) with assorted additives
including anti-wear, anti-oxidation, anti-sludge, foam inhibitors.

Ok.

I'd
go for something that claims to be suitable for m/c forks since a
trolley jack oil doesn't really need anti foam performance, for example.

Ok thanks ... I was only wondering if it was just marketing.

Talking to an old motorcycle mechanic the other day and he said he'd
often used ATF in forks and it worked well?

ATF is the same sort of stuff and probably very similar viscosity.
There's perhaps not quite the same scope for foaming as in forks.


When I drained the forks on daughters new bike the other day the leg
the PO said he's changed the seal on (but was still leaking) had some
cleanish fluid in it but the other side that had an unchanged seal in
it wasn't leaking because there was only an eggcup of a grey sludge in
there (grey from the ally of the from the inside of the fork leg). ;-(

In one way I'm glad it showed the signs of needing a 'good going over'
as otherwise she might have been riding it like that.

Once I've got the front forks / wheel / mudguard / new disk and pads
and rebuilt caliper back on, I'll change the oil and check the air
filter and take it out for a test ride for her (assuming it's not
still raining ... ). ;-(

I'll probably get mine back on the road as well as I like to have at
least one bike available, just in case ... and it's nice to have a
pootle round the B roads. You get some nice dry days, even in the
winter and she's bound to want to go for a little ride out with her
old Dad. ;-)

I don't often feel tempted to get another bike, I get my kicks (as it
were) from horses these days. However having been dumped on a rock the
other day leaving me with a very bruised glute I do sometimes wonder.

:-)