After just going through a little debacle with having to replace the power steering pump and lines in the Impala SS after the pulley shaft bearing completely destroyed itself, I decided to spend a few extra dollars on Red Line power steering fluid, despite the fact that I have quite a surplus of Maxlife ATF, Castrol Mercon V, Valvoline Mercon V, and Mobil 1 ATF.
So.....in the spirit of contributing to the global BITOG knowledge database:
While I cannot disclose the specifics of GM p/s fluid spec 9985010, here are a few observations:
*Let's expound on that last one. Time and time again, I have read people make the argument that ATF (and sometimes ISO 32 hydraulic oil) is "good enough" for most power steering systems. I don't want to split hairs since practically speaking it may only make a marginal or even imperceptible difference (laboratory test environment vs. real-world automotive environment), but I challenge anyone to name a so-called "Dex/Merc" ATF that is rich in zinc. While power steering systems are relatively straightforward hydraulically compared to transmissions, the fluid may still be pressurized to 1200+ psi and temperatures of 125°C or higher are not uncommon.
Conclusion: Use with confidence!
So.....in the spirit of contributing to the global BITOG knowledge database:
While I cannot disclose the specifics of GM p/s fluid spec 9985010, here are a few observations:
- Flash point is well within spec (shouldn't be a surprise)
- Kinematic viscosity of this sample looks a tad bit on the low side compared to spec'd initial KV, even slightly lower than Red Line's published "typical" viscosity after shear.
- Zinc and phosphorus both exceed the spec'd minimums by a significant margin.*
*Let's expound on that last one. Time and time again, I have read people make the argument that ATF (and sometimes ISO 32 hydraulic oil) is "good enough" for most power steering systems. I don't want to split hairs since practically speaking it may only make a marginal or even imperceptible difference (laboratory test environment vs. real-world automotive environment), but I challenge anyone to name a so-called "Dex/Merc" ATF that is rich in zinc. While power steering systems are relatively straightforward hydraulically compared to transmissions, the fluid may still be pressurized to 1200+ psi and temperatures of 125°C or higher are not uncommon.
Conclusion: Use with confidence!