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Does anyone use brake fluid in their power steering?

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Someone had once indicated to me that a lot of parts store power steering fluid is just repackaged brake fluid. What are supposed to be the differences between the two?

There's a thread I'll link to if I can find it. There were some interesting remarks inside.

http://www.dsmtuners.com/forums/newbie-forum/151848-special-kind-power-steering-fluid.html

EDIT: After some reading it sounds like power steering fluid is actually compressible, unlike brake fluid(?). I'm not sure if freezing temperature is relevant.
And what of ATF vs power steering fluid? The friction argument was interesting.
 
Brake fluid is hygroscopic, meaning it readily bonds with water effectively lowering the boiling point. It is also not a very good lubricant. Definitely don't recommend. If moneys tight, dextron 3 is compatible with power steering fluid.
 
Someone had once indicated to me that a lot of parts store power steering fluid is just repackaged brake fluid. What are supposed to be the differences between the two?

There's a thread I'll link to if I can find it. There were some interesting remarks inside.

http://www.dsmtuners.com/forums/newbie-forum/151848-special-kind-power-steering-fluid.html

EDIT: After some reading it sounds like power steering fluid is actually compressible, unlike brake fluid(?). I'm not sure if freezing temperature is relevant.
And what of ATF vs power steering fluid? The friction argument was interesting.

I don't see where they mentioned brake fluid at all. They were talking about ATF.
 
ATF, and sometimes even engine oil are used for power steering on semi and large three axle trucks.
 
PieEyedPiper said:
There's a thread I'll link to if I can find it. There were some interesting remarks inside.

http://www.dsmtuners.com/forums/newbie-forum/151848-special-kind-power-steering-fluid.html
I don't see where they mentioned brake fluid at all. They were talking about ATF.
They didn't. They did, however, have interesting remarks.


ATF, and sometimes even engine oil are used for power steering on semi and large three axle trucks.
Wow, engine oil. I wonder what the power steering engineer has to say about that one :snicker:
 
Do not use Brake fluid in a power steering system unless you want to replace every single part of you steering system. Had a customer think he was smart enough to top up his "brake" resevoir one time, that was an expensive mistake. We will just say it will cause leaks....alot of leaks...lots and lots.
 
Do not use Brake fluid in a power steering system unless you want to replace every single part of you steering system. Had a customer think he was smart enough to top up his "brake" resevoir one time, that was an expensive mistake. We will just say it will cause leaks....alot of leaks...lots and lots.

I guess I just never really thought about it. I really just ASSumed they were really similar. I suppose I don't have to be as worried about getting power steering fluid on my hands anymore if it's not the poison that is brake fluid.

Does anyone know what kind of rubber material SS clutch and brake lines are made of to resist brake fluid?
Still interested in the ATF vs PSF thing though.
 
Most P/S fluids are very similar to ATF, just different additive packages for anti-foaming etc.. Some of them are not and have base oils and special additives in the for the vehicle specific system they are used in. Always use the fluid the factory recommends and you will be good. Change it to something different at your own peril. I've seen first hand the disaster putting the wrong fluids in causes. $$$$$
 
Most P/S fluids are very similar to ATF, just different additive packages for anti-foaming etc.. Some of them are not and have base oils and special additives in the for the vehicle specific system they are used in. Always use the fluid the factory recommends and you will be good. Change it to something different at your own peril. I've seen first hand the disaster putting the wrong fluids in causes. $$$$$

Fortunately, I've never had to even top it off. I'm assuming Dexron II is in it currently.
My neighbor was doing some shit to his car the other day and asked me if he can use brake fluid in his power steering. Not knowing, or having ever considered it, I just said no. But he also wanted to use brake fluid from 1980.
 
They only thing I found about ATF vs P/S fluid is that the newer cars HAVE to use the P/S stuff, and older cars like ours take ATF but can use the P/S fluid.

I used Valvoline ATF in my P/S system with a new steering rack and it works excellent.
 
I guess I just never really thought about it. I really just ASSumed they were really similar. I suppose I don't have to be as worried about getting power steering fluid on my hands anymore if it's not the poison that is brake fluid.

Does anyone know what kind of rubber material SS clutch and brake lines are made of to resist brake fluid?
Still interested in the ATF vs PSF thing though.

The rubber brake hoses use an EPDM tube, the SS hoses use a teflon, or PTFE tube. PTFE is some amazing stuff. Superior heat and cold temperature range, it absolutely does NOT age at all, and remains inert to almost any chemical. Those "heat barrier" gaskets that the shops are selling for our intake manifold and throttle bodies are PTFE as well.

Oh, on the subject of mixing and matching fuilds, have any of you ever seen what happens when you mix DOT 5 brake fluid with DOT 3....
 
Back in the day, Late 60's thu the 70's Ford actualy told you to use ATF in the PS of the cars they built.

Ever seen "Type F" trans fluid. That is what you used in old Fords.

Honda has a special PS fliud they have to run.
 
Brake fluid is glycol based, PS and ATF are not. The seals in the non-glycol based systems will swell (substantially) if the fluid is replaced with glycol and vise versa, rendering either unuseable. Made this mistake once a few decades ago. Toss the seal of one into the other fluid and watch them grow, it is profound and irreverseable.

That said, an old mechanics trick is to put a small amount (a shotglass or so) into a leaking automatic transmission or power steering system to slightly swell the seals. It does work, I did this in a '67 Imperial that was losing its entire contents, through the pump seal, in about 5 miles. I put in a shot glass worth of DOT 3 and topped it off with ATF and it NEVER leaked a drop again. YMMV.
 
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