Cooling Steering Fluid

Rek

Rek

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My donor car has a cooling apparatus - a serpentine aluminium cooling array which the steering fluid passes through. This metal tubing sits in front of the main radiator. There was nothing like this on my '71 CS

My question is, do I need to repllcate this and has anyone had any issues with steering fluid heating up?

Any experience or advice welcome.
 
Thanks Mike - thats interesting. I feel that I won't be putting that much stress on the fluid and maybe in the E34 (donor) BMW was designing the car for the various climates where it might operate so as to survive in desert as well as the frozen north.

Notwithstanding this, the high pressure hose needs building so I will incorporate a junction where I can attach a cooler if needed.
 
I overheated the power steering in my Coupe while chasing a bunch of Lotuses during a Lotus drive. I seriously doubt most of us would drive a Coupe that hard often enough to require this, but I'm a testament to the possibility of it happening.

I don't think it would happen auto crossing or tracking either. It was about 30 min before it manifested, which is longer than most sessions on the track, and definitely an auto X.
 
Luis A. said:
How did you know the fluid overheated?
Click to expand...

I could hear the pump aerating fluid, it was whining, the power steering was inconsistent, the lines were extremely hot, and I could smell fluid burning. I gave it a fluid flush at the end of the day and it's been fine since.
 
What type of fluid are you using?

The reason I'm asking is that I researched this a couple of years ago and concluded that although Dexron VI has presumably replaced Dexron III, it is better to use Dexron III type fluids, which was the original specification (actually Dexron II/B) due to the viscosity. By using Redline's D4 ATF, their Dexron III spec fluid, I get a synthetic base with its improved longevity and performance in high temperature use.
 
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No idea what it had in it at the time I over heated it. It was the last fluid I hadn't flushed.

I'm running a Dexron III now.
 
My CS has an issue with diminishing power assistance in very hot weather. So far it has only happened in Italy. No additional noises though.

Power assistance has never been terribly great, and I always thought it was part of the car's character. There is a big difference in steering effort when the engine is off so it is working. It could be that the pump is not delivering its full pressure. It is leaking slightly too so a change shouldn't hurt. I have a complete system lying around that I will cosmetically fix up and then fit this summer to see if it makes a difference. Or are you saying I should change the fluid? It's probably still on the original stuff...
 
Chamonix_E9 said:
My CS has an issue with diminishing power assistance in very hot weather. So far it has only happened in Italy. No additional noises though.

Power assistance has never been terribly great, and I always thought it was part of the car's character. There is a big difference in steering effort when the engine is off so it is working. It could be that the pump is not delivering its full pressure. It is leaking slightly too so a change shouldn't hurt. I have a complete system lying around that I will cosmetically fix up and then fit this summer to see if it makes a difference. Or are you saying I should change the fluid? It's probably still on the original stuff...
Click to expand...


Before condemning your fluid type or the pump, consider the oft overlooked filter that sits in the reservoir. It could be restricting flow.
http://www.e9coupe.com/forum/showthread.php?t=10935
http://www.e9coupe.com/forum/showthread.php?t=6196



The hydraulic power steering must be bled whenever the hydraulic system is opened or the oil level falls so low that the vane type pump draws in air.
Fill the reservoir up to the rim with oil¹). Turn the engine over with the starter and continue to add oil¹) When the oil level no longer falls, run
the engine at idle speed. Turn the steering wheel rapidly from one full lock position to the other and back until no further air bubbles rise in the reservoir.
During this operation and afterwards the oil level must always remain at the upper mark. ¹) For oil grade and quantity, see technical data.
Click to expand...
For starters:
p_107.jpg
 
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