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About Hydrolic Fluid

What kinds of hydrolic fluid are there?

Where can I get fluid?

Which is best?

David Bruckmann:dave@bruckmann.com
Fri, 12 Apr 1996 16:15:12

The debate about which fluid is OK rages on and on. The most logical
argument I've ever heard for NOT using Dexron or Type-F is as follows:

Automatic transmission fluids contain "friction modifiers" which are
designed to reduce slippage of the clutches in automatics. The presence of
these friction modifiers leads to faster wear of seals (particularly the
teflon rings) in the Citroen's hydraulic system. Apparently, type-F fluid
has even MORE friction modifiers in it (which is why there are often big
warnings about not using it in systems designed for Dexron). So, although
the ATF-type fluids are mineral based (as opposed to vegetable-based like
brake fluid), they have other properties that are less than ideal in a
Citroen context. In an emergency, you can basically use anything (including
engine oil -- clean engine oil!!) except a DOT3/4/5 fluid.

So, if I were you, I'd ditch the Dexron and use either pure LHM (if you
have money kicking about) or buy a pail of Texaco Aircraft Fluid (Esso
equiv. is called Univis J-13, at about $2.00/litre in 20 litre pails).
Alternatively, you could use the Univis to flush the system, and then drain
and fill with LHM. That way you've replaced traces of ATF with traces of
J-13, a safer compromise.

One other thing... there is apparently a new verison of LHM, called
LHM-Plus, with improved lubrication properties. Anyone have access to this
in North America? I'm told it's the bee's knees in Europe.

Anthony Boutard:ab@friends.org
Sat, 13 Apr 1996 03:28:13

>So, if I were you, I'd ditch the Dexron and use either pure LHM (if you
>have money kicking about) or buy a pail of Texaco Aircraft Fluid (Esso
>equiv. is called Univis J-13, at about $2.00/litre in 20 litre pails).

Per earlier discussions, this is fine if the viscocity profile
is not a problem.  That is, you don't have citromatic.  The aircraft 
fluid has a different viscocity profile which becomes a problem 
for citromatic at low temperatures.  Interestingly, the layout of the
hydralic piping cools the fluid very efficiently.  In cold 
weather the clutch engagement is slowed and the idle does not kick
down properly when the Texaco fluid is used, at least in my
experience. 

In an ID, you would not notice the problem.  If your system
has only minor leaks, LHM is the best option.  If it is a 
gusher, use the Texaco oil until the problem is fixed. 

Adam:1ADAM12@delphi.com

A mention of the LHM-plus...we/I haven't seen any of this stuff in the
states, BUT during my recent RAID LAPLAND travels (I'm sorry that I have
yet to get these accounts into a story format for you all to enjoy) I did
notice the LHM-plus and LHM-extra which I found was made by no less than 5
manufacturers other than TOTAL, which suprised me.  There was nothing on the
plus/extra bottles to tell you what was new, only a mention of the original
Citroen spec #.  Does anyone actually know what is so new and improved about
the "plus"?

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