What really is PS?

[boxcab]

Is it simply an R & O oil or an hydraulic oil? It really can't be all that mysterious, given that most specs call for "PS" fluid or ATF. What would be a suitable off-the-shelf synthetic alternative, apart from the obvious ATF applications?

Viscosity? What else? Why, of all things, is PS fluid so generic?

 

[PT1]

Good question...I'm trying to figure out what's in RP MaxEZ synthetic.......well kept secret I guess. Anybody have any idea?

 

[onion]

I can't speak with any authority on the subject. I can only say that I've been told that it's essentially hydraulic oil. I've seen power steering oil, hydraulic oil, and atf mixed and/or used interchangeably in multiple applications more times than I can recall... with never a problem resulting.

 

[onion]

https://www.cbest.chevron.com/generated/MSDS/PDS763683.PDF

Havoline power steering fluid:

TYPICAL TEST DATA
Typical test data are average values only. Minor variations
which do not affect product performance are to be expected in
normal manufacturing.
Product Number 221806
MSDS Number 10825
API Gravity 31.2
Viscosity, Kinematic
cSt at 40°C 39.7
cSt at 100°C 7.7

Viscosity, Saybolt
SUS at 100°F 201
SUS at 210°F 52.0
Viscosity, Brookfield
cP at -40°C 30,000
Viscosity Index 167
Flash Point,°C(°F) 210(410)
Pour Point,°C(°F) -48(-54)
Color Red

Looks an awful lot like run-of-the-mill ATF, if I recall.

 

[Gary Allan]

It was so much simpler when we just put in ATF.

 

[bruce381]

High VI
Low PP
HAS friction modifiers
HAS AO and AW
HAS seal swell.

yeah kinda like a ATF fluid BUT there is a full add pak avaible to make a GM approved oil and labeled as such not just ATF tho that works in most cases I guess.

 

[PT1]

Here are the RP MaxEZ specs from their website


Viscosity

cSt @ 40°C
45.0

cSt @ 100°C
9.0

SSU @ 100°F
228

SSU @ 210°F
57

Viscosity Index
187

Flash °F
400

Fire °F
445

Pour °F
-75

Foam Test

Sequence I
0 ml / 0 ml

Sequence II
0 ml / 0 ml

Sequence III
0 ml / 0 ml

Density

A.P.I.
33.03

Specific Gravity @ 60°F
0.86

Pounds / Gallon
7.16


*ALL PROPERTIES ARE TYPICAL AND MAY VARY