Power steering fluid

The neon is apparently boiling power steering fluid. 

I have some heat shielding to do, but need to replace the missing fluid. 

What to replace it with?

Prestone is current. 

Professor brap suggests atf for higher boiling point. 

Dad swaers by napa power steering fluid as a higher boiling point fluid.

What, and why? Figured this could be a good discussion.....

Ford now uses Mercon V in anything with hydraulic ps... before that it was III... so trans fluid is my suggestion! 

A higher end brand?  (Royal Purple, Lucas, etc.).  Check out their websites for info.  You may possibly be drawing air in somewhere.  Air in the system will cause problems with heat.  Check O-rings, hoses etc.  Is the pump, hoses and so on, from the swap?

What type of fluid is recommended in the owner's manual?  I did a quick search and found one source that said "2000-2001 is ATF+3 and 2002+ is ATF+4 ".

Is it boiling or frothing? My Miata used to froth its PS fluid when making lots of quick transitions at autocross. The fluid wasn't particularly hot, but didn't like getting pushed back and forth so quickly. Red Line PS fluid cured it.
 

Im uncertain if boiling or frothing, to be honest. It only does it during autocross, not on the street.. . 

Owners manual reccomends plain power steering fluid. Pump, lines, rack, etc are all stock 1997 neon parts. Nothing exotic. 

My thoughts were to boiling, as the long tube header runs much closer to the rack, the resivoir, and the lines. 

Is putting a cooler in the low pressure PS line an option?

MadScientistMatt said:

Is putting a cooler in the low pressure PS line an option?

This would probably be the best way to solve the issue.  I'm running a cheap cooler on my hydroboost setup just for insurance.  Link

Some heat shielding on the lines that are near the header wouldn't be a terrible idea either.

If it's getting the fluid hot enough to get too thin for good pump operation or hot enough to burn the fluid, add a cooler in the return line.  It's low pressure and even a small cooler will often make a huge difference.  

i went through this with the Korean cars. The Elantra, Forte and Tib all had the same issue. Adding coolers helps, but a good fluid is more beneficial. I ended up using Amsoil's P/S fluid as they had one of the highest boiling points and more anti-foaming agents. If you can add capacity with a cooler, that will help. gives the fluid more "down time" in the reservoir to let the air escape and cool down. 

I will not be adding a cooler if i can help it, honestly. Wrong vibe for the car....

A "cooler" for most of these was literally a piece of metal pipe that ran in a loop in front of the radiator. Adds a quarter of a quart and helps get temps under control. 

Can you measure the fluid temperature in the reservoir with an infrared gun?

PT Cruisers all had power steering coolers, both turbo (part of the rad) and NA (separate and attached to the subframe).  I'm pretty sure it's the same case for 2nd gen Neons.  The little separate ones with brackets on the subframe might adapt to a 1st gen pretty well and be hidden from view.

I'm currently piecing together an electro-hydraulic PS setup for my Escort GT.   I needed a cooler & started shopping through various OE options... I found one that's ideal for my setup & might work well for you too.  Its from a Dodge Caravan of all things... nice and compact, built in mounting bracket with 2x threaded holes.  Should be extremely easy to mount where I need it.

https://www.dodgeparts.com/oem-parts/mopar-power-steering-cooler-4743140ac

I bought one of these NOS, cosmetically damaged ones on ebay.  Straightened a few fins and it's good to go.  https://www.ebay.com/itm/184680684999

I think ATF+3 or ATF+4 is what I used in my rallycross Neon, although it still boiled over on some of the courses that involved a lot of tight turns, even with a heat shield.  Didn't help that it was a two driver car.  Would it make sense to switch to a 2nd gen ps pump to get the reservoir away from the exhaust?