What's the upper temperature range for power steering fluid?

[Irun]

I asked ChatGPT 03 and below is the answer I received. Does this sound correct? Asking because I'm adding a cooler and trying to determine if a push lock hose with a max temp of 257°F is sufficient. I'm guessing that it's okay, because I'd have other issues before getting to that temperature.

Typical temperatures when rock‑crawling​

Operating context	Common fluid temp	What’s going on
Normal on‑road driving	150 – 180 °F (65 – 82 °C)	Moderate steering effort plus good vehicle speed keeps the return‑line cooler supplied with airflow. Pirate4x4IH8MUD Forum
Slow technical off‑road/rock crawling	≈ 200 – 240 °F (93 – 116 °C) sustained, with brief spikes up to ≈ 250 °F	Very high steering load at idle/low rpm and almost no ram‑air through the factory “paper‑clip” cooler lets heat soak quickly. Pirate4x4JL Wrangler Forums
Warning / damage zone	> 250 °F (> 121 °C)	Fluid oxidation accelerates, seals harden, pumps cavitate and may “puke” fluid through the cap; many OEM systems will trigger a steering‑temp warning light around this point. Pirate4x4Grassroots Motorsports

Rule of thumb for trail rigs: keep the fluid under ~220 °F whenever you can; treat anything over ~240 °F as a sign you need more cooling or higher‑spec fluid.

 

[Chris]

@mrblaine likely knows.

 

[KennethS]

The Gates web site says their power steering pressure hose is rated for -40F to +300F.

https://www.gates.com/us/en/fluid-p...17-000000-000000.v.33170108.html?related=true

 

[mrblaine]

I asked ChatGPT 03 and below is the answer I received. Does this sound correct? Asking because I'm adding a cooler and trying to determine if a push lock hose with a max temp of 257°F is sufficient. I'm guessing that it's okay, because I'd have other issues before getting to that temperature.

Typical temperatures when rock‑crawling​

Operating context	Common fluid temp	What’s going on
Normal on‑road driving	150 – 180 °F (65 – 82 °C)	Moderate steering effort plus good vehicle speed keeps the return‑line cooler supplied with airflow. Pirate4x4IH8MUD Forum
Slow technical off‑road/rock crawling	≈ 200 – 240 °F (93 – 116 °C) sustained, with brief spikes up to ≈ 250 °F	Very high steering load at idle/low rpm and almost no ram‑air through the factory “paper‑clip” cooler lets heat soak quickly. Pirate4x4JL Wrangler Forums
Warning / damage zone	> 250 °F (> 121 °C)	Fluid oxidation accelerates, seals harden, pumps cavitate and may “puke” fluid through the cap; many OEM systems will trigger a steering‑temp warning light around this point. Pirate4x4Grassroots Motorsports

Figure it to be about the same as trans fluid.

 

[Richard Mccullough]

For most rock‑crawling you’ll stay below 240 °F, and you really only hit the danger zone above 250 °F.