Ready to Fill, PSF or ATF, in a GM

[rn2fine]

Just put a rebuilt power steering gearbox and power steering pump in my 72 Suburban. The system is is empty of any fluid and I am contemplating whether to put in PSF or ATF. I live in AZ where temps are high. Suggestions?

 

[Jim 5]

If your power steering system was originally spec'd for an ATF, then I'd definitely run a full synthetic like M1 ATF or Amsoil ATF. Power steering systems can run really hot without any provision made usually for cooling.

It's pretty much the ideal application for a synthetic, especially in the context of long change intervals. Most PS systems don't hold a great deal of fluid, so going synthetic isn't typically a cost hardship.

 

[EricF]

Drop in some Redline PSF. GM's don't like ATF

 

[George7941]

My 2006 Sierra, with rack and pinion, specs PSF but I replaced the factory fill with M1 ATF anyways about a year ago and, so far, it has worked well. It greatly lessened the squeal when starting up at 0 deg F and below.

 

[GMorg]

I just switched my GM to Redline PS fluid a few weeks ago. The steering is much smoother now.

 

[tig1]

Synthetic ATF like Amsoil or M1 ATF(which is what I use) will work as well as anything there is.

 

[Jim 5]

Originally Posted By: EricF
Drop in some Redline PSF. GM's don't like ATF


This statement is true for modern GMs.

Remember, we're talking about a nearly 40 year old GM truck. I'm betting it has a saginaw "canned ham" power steering pump (named as such because the reservoir that surrounds the pump is built in the shape of a "Spam" can), which was likely spec'd on ATF into the early 90's or later. I have one of these in my ford application and it was spec'd for type F ATF. Same pump.

Anyhow, I think the wear factor is heat/fluid cleanliness. I would go with a synthetic fluid where ATF is permitted. Redline will likely be a synthetic so it would be a good choice, but expensive. For my money, I'd go with a garden variety Dex III Synthetic - available at any wally world.

 

[tig1]

They don't sell much for synt ATF at WM in my area. I can't remember seeing any at all.

 

[EricF]

If the p/s pump is rebuilt by A1 Cardone, they actually don't specify ATF for their pumps. They have an "approved" list of tested and approved p/s fluids. Redline PSF isn't on the list, however I called the tech dept, and they said 99.9% chance it will pass. they haven't bought the redline psf, and allegedly there's none for sale in their area. I was supposed to send a bottle but never did.

They did say if ATF was spec'd as OE fluid it would be OK to use it as well.

 

[Jim 5]

Originally Posted By: tig1
They don't sell much for synt ATF at WM in my area. I can't remember seeing any at all.


Interesting. I can get supertech synthetic Dex III here. We're used to having way less selection than our friends in the states.