Power Steering Fluid

[JMF]

What power steering fluid should I be putting in ? I have ATF Type F for my 70 Mustang, would that be ok ? Also should the cap be vented ? It does say vented on it but I can't see any holes on it, I have fluid coming out of the top on full lock, thanks

[Bronzedodge]

ATF will swell the seals.  I have had better luck with regular power steering fluid.  If you are overflowing at full lock, it is either overfull or there's a bad seal in the box.  The box has to separate the left and right power chambers, over 500 psi at times; from return pressure, which is very low.  I suppose the cap vent could be clogged, never had that happen.  How is it running w/ the cap off?  There's a cold and hot level marked on the dipstick.

[JMF]

It's definitely low because it's not showing anything on the dipstick when cold

[John_Kunkel]

ATF will swell the seals. 

Nonsense!!! Notice the ATF product description below states it can be used as a P/S fluid.

http://www.valvoline.com/our-products/automatic-transmission-products/type-f

[A383Wing]

ATF was used as power steering fluid in all the major carmakers of the 60's & 70's

[c00nhunterjoe]

How long are you holding it at full lock?

[JMF]

Only for simple manoeuvres like 3 point turns etc, couple of seconds etc

Where is the vent on the cap ?