cybertronicify

Hello everyone! What type of power steering fluid do i use for my 2003 S430? Its on the 20C MIN line when the engine is at 80C. When i replace my fluid, do i need to drain the old fluid out?

VMAX7

CHF11S pentosin fluid on ebay is the cheapest and is oem.

Just add to existing fluid.

cybertronicify

I ended up buying from Amazon because i have prime free 2 day shipping. Can you check if this is the same one? Thanks!

s55_hapa

Yes, that's the one I used on my '05 S55.

ibeforreal

You can also use the Pentosin CHF 11 for the pump in your trunk that hides in the section by the battery.

cybertronicify

What is that pump that is located next to the battery? Are you talking about the vacuum pump? Would it fix the need to pull the fuse every month?

ibeforreal

The pump located next to the battery is for the trunk opening/closing. If your trunk opens slowly or doesn't shut properly the first thing you should check is that pump to make sure it has fluid.

cybertronicify

Oh my 2003 S430 doesn't have the self closing trunk. It only has the assist where you have to manually push it down until it clicks.

ibeforreal

Do you have soft close doors? The nice thing about the self close trunk is that you can open and/or close from the door button. You can also lock the car from the trunk.

cybertronicify

Soft close doors are standard on the W220 models (at least in the US of A). But i can see how handy the self closing trunk can be. Happened countless times, i'm here holding two big bags of stuff and no hand to close the trunk.

wallyp

"Are you talking about the vacuum pump? Would it fix the need to pull the fuse every month?"


The PSE is computer controlled, and if there is a system leak, the computer is smart enough to kill the specific unit that has failed (one door, for example). It is also smart enough to kill the pump if there is a continuing leak.


Pulling and replacing the fuse resets the computer, so it will try again. If the leak has not been repaired, the computer will eventually shut the system off again. If you keep resetting it without repairing it, you will eventually burn out the pump - $$$.

ibeforreal

I agree with Wally the PSE pump controls the soft close for the doors and also the gas cap door. They are about $800.

VMAX7

I have an extra vacuum pump if anyone needs.

cybertronicify

It seems like only the driver door is leaking, as it is always the first one to go. The passenger door gets pretty much equal use and its perfectly fine. Time to whip up some epoxy and some tools and fix the leak. Thanks for the tips everyone!


OH and... My power steering is so much better after the fluid change. I didn't want to introduce bubbles into the system so only 80% of the fluid was flushed. But that was enough to make a massive difference in the smoothness of the steering wheel.

Old fluid was BLACK smelled burn't
New fluid was coolant like GREEN.

ibeforreal

Driver's door leaking could be the door lock actuator. Easy enough to check it out. Take the door panel off and the moisture barrier, then if you hear a hissing sound it is more likely the actuator for that particular door. The white plastic cap on those actuators are under a tremendous amount of pressure and eventually just wear out. Check out this thread and procedure I wrote for the actuator lock problem.

https://mbworld.org/forums/s-class-w...l-process.html

cybertronicify

John, that is a really nice write up! I should have done that when i checked on my driver side airbags. Right now the door stopped working, so i'm going to leave it like that until i fix the actuator. Thanks for the help everyone!