mobil 1 synthetic vs. pentosin 7.1
07-20-2006, 07:32 AM
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mobil 1 synthetic vs. pentosin 7.1
i recently posted a thread to the citroen list, and the answer may be of interest:
me: i have spent a little time on an audi list (dealing with the other problem child) and i have a question that i may already know the answer to, to wit:
my audi uses pentosin 7.1 green mineral hydraulic fluid for the power steering and brake assist servo. i use the same fluid to float the cx (i know, i know more expensive than LHM, but locally available). the people on the audi list have talked about using mobil 1 synthetic transmission fluid as a replacement for the 7.1, and in fact mix the two. it is said to help with hydraulic fluid leaks, works just as well as 7.1, and is much cheaper and more available.
am i dreaming up the wrong tree by thinking it would work in the cx and mix flawlessly with 7.1?
chris in australia: Simple answer is NO.
Mil Spec 5606. ie:Aeroshell Fluid 41 & Mobil Aero HSS are the only near
viscosity equivalents, but these 2 were around before LHM was specified by
Citroen in I guess about 1963 (????)after their initial precarious Brake
fluid hydraulic systems, suggest there was a reason!! Since then LHM has
been thru at least 2 revisions.
Some say you can use Auto Trans fluid too, & it will wear your hydraulic
system out for free too (it has friction enhancers), apart from having
totally wrong viscosity characteristics (Viscosity Index VI).
Engine oil should only be used as an emergency, again is VI is way off spec.
Regards,
Chris Stuart
Perth, Auss
me: i have spent a little time on an audi list (dealing with the other problem child) and i have a question that i may already know the answer to, to wit:
my audi uses pentosin 7.1 green mineral hydraulic fluid for the power steering and brake assist servo. i use the same fluid to float the cx (i know, i know more expensive than LHM, but locally available). the people on the audi list have talked about using mobil 1 synthetic transmission fluid as a replacement for the 7.1, and in fact mix the two. it is said to help with hydraulic fluid leaks, works just as well as 7.1, and is much cheaper and more available.
am i dreaming up the wrong tree by thinking it would work in the cx and mix flawlessly with 7.1?
chris in australia: Simple answer is NO.
Mil Spec 5606. ie:Aeroshell Fluid 41 & Mobil Aero HSS are the only near
viscosity equivalents, but these 2 were around before LHM was specified by
Citroen in I guess about 1963 (????)after their initial precarious Brake
fluid hydraulic systems, suggest there was a reason!! Since then LHM has
been thru at least 2 revisions.
Some say you can use Auto Trans fluid too, & it will wear your hydraulic
system out for free too (it has friction enhancers), apart from having
totally wrong viscosity characteristics (Viscosity Index VI).
Engine oil should only be used as an emergency, again is VI is way off spec.
Regards,
Chris Stuart
Perth, Auss
07-20-2006, 07:59 AM
#2
He's reading that as yoou are using engine oil.
The fact remains that Audi did use ATF in older versions of the system (so I've been told), and several of us have used the Synthetic ATF with good results.
Try reposting and clarify that ATF is used.
Try reposting and clarify that ATF is used.
07-20-2006, 09:10 AM
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But... Older sytems *specified* atf as opposed to Pentosin..must be a reason..
Older sytems *specified* atf, while some of the newer specify the 'mineral oil' pentosin. They *are* different systems! I'm sure there is a reason for the specifically specified different liquids. I just don't know why.
(For that matter, some manufacturers specify ATF for manual transmissions...)
I'm also sure that there somewhere in the world, there should be a similar and compatable liquid.
I've heard of a hydraulic oil that some farm tractors use. Generically called 'trans-hydraulic', in that it's gear oil that is also used in the tractror's hydraulic system. May bear further investigation at the farm Co-Op store..?
(For that matter, some manufacturers specify ATF for manual transmissions...)
I'm also sure that there somewhere in the world, there should be a similar and compatable liquid.
I've heard of a hydraulic oil that some farm tractors use. Generically called 'trans-hydraulic', in that it's gear oil that is also used in the tractror's hydraulic system. May bear further investigation at the farm Co-Op store..?
07-20-2006, 10:15 AM
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Re: He's reading that as yoou are using engine oil.
and some of us are going on 4 years with ATF our PS system instead of P / no leaks .
1987 5000 qt .
as it's my winter car I don't care that much , but have not had one problem since 2002
1987 5000 qt .
as it's my winter car I don't care that much , but have not had one problem since 2002
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07-21-2006, 05:41 AM
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Older = 83 urq too..
83 Urq uses ATF too. PS runs both steering and brake servo, but bomb looks a bit different, and I suspect that the 'mystery thing that looks a bit leaky that the bomb mounts on' is different too.