Bimmerfest - BMW Forums - View Single Post - DIY - E39 525i Fluid Triple Play (PS, diff & tranny fluid change)

bluebee · #31 03-23-2011, 10:11 AM

I added a link to this thread in the bestlinks for future reference.

In addition, I linked to it in the summary fluid printout:
- BMW E39 fluid summary printout for your glovebox (1)

Doru suggests we replace the fluid in the power steering reservoir at every oil change:

It only takes about half a quart to suction out and then refill:

Most say you can't remove the filter but some (JimLev) say you can, so see his DIY on cleaning the filter.

Just make sure you use the right fluid. Do not use PSF; use DexronIII/Dexron VI ATF!
(This was my rookie mistake a few years ago when I first bought my bimmer & changed the fluids.)

Tying the PSF with the oil change makes sense, especially since the o-ring in the cap deteriorates at about the same rate as the two little o-rings in the lower half of the oil filter housing; so replace all three o-rings at the same time (every few years):

At about the same time, check the lower reservoir hose for leaks & fix it the cn90 way:

And, climb underneath to fix the power steering pump hose leaks also:

Otherwise, you face a power steering pump autopsy like this:

As for the power steering fluid pump filter, here is JimLev's procedure:
- E39 (1997 - 2003) > Looks like PS systems are the hot topic today

Quote:

On the V8 the drain plug on the PS pump will empty almost all of the fluid

There is apparently a screw or bolt holding the filter in place:

Apparently the circular screen will simply lift off at this point:

JimLev suggests you flush it all out with gasoline or other suitable solvent.

He also suggests you plug the filler cap with a Q-tib cotton swab:

But most of us recommend simply replacing the filler cap o-ring every few years.