checking power steering fluid




But today I remembered and thought I would check the fluid level just to do sure. The dipstick has two measurements - one at 80 degrees Celsius and another just below at 20 degrees Celsius - so I suppose either would work but I'd rather do what is most accurate.
Also, does the engine need to be running to get a proper reading? Is it better when the engine is properly warmed up after making a few lock to lock turns or can I do this cold in the morning before the car has been started?
For background, I haven't checked the fluid before on this car. My other cars have a nice clear reservoir with clearly marked max and min lines which makes it easy. My car has been dealer serviced thus far and I know it is listed as part of the procedures to check it with each service, but I always doubt they check all those things. I haven't noticed any signs of leaking on the ground or around the reservoir. PS fluid changes are not in the maintenance manual AFAIK
Last edited by thefisch; Aug 5, 2017 at 01:59 PM.
added some ch 11 (cant remember since it was couple months ago) and noise went away.
i also read some articles though as i wasnt sure... and at this point i cant remember , but i did add a small amount.




Just didn't know if it made a difference if you checked cold or warm. The MB workshop manual (link is for coupe but should be the same) says the ignition should be off and doesn't say whether hot or cold is better, just says use the reading for the current temperature. I may try it both ways. There are threads about changing or flushing the fluid - don't want to bother with that now - just trying to make sure it is topped off.
Seems like the most prevalent fluid mentioned for adding is the Pentosin CHF 11S which runs about $20 online and in some stores. My local NAPA has another option which they tell me they ordered specific for someone's MB. Going to see if it meets spec. https://www.napaonline.com/en/p/AOF0009898803 Anyone try this other one?
I've never checked the fluid when the engine is running, as the reservoir (at least on other vehicles) can get slightly pressurized from the fluid circulation at the pump. MB reservoir is above the pump, so less chance of splash, but on our Silverado, taking the cap off when the engine is running invites a nice coating of fluid everywhere lol.
I bought the recommended Pentosin fluid online as my thinking was not to mix fluids when topping off. I also pull some PS fluid out of the reservoir every oil change or so using the good old turkey baster method and replace with new fluid. Over the long run it may not be all new but better than all old fluid.









During my searching, I also came across a Prestone European Power Steering fluid that is commonly available at most auto parts places, even Walmart has it. It goes for around $7-8 and says it is compatible with CHF 11S. Anyone try it?
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So I decided to call some other dealers just to see what they said. The next two parts departments I called said to use Pentosin - one didn't know much about it but another said that's the fluid they use in all their cars now. When I asked about the different colors and mixing fluids, they didn't say offer anything other than that is what their system told them.
I called a fourth dealer just outside my area. He said the system said to use Pentosin. When I asked about the different colors of fluid, he cautioned me against mixing different types of fluids and it can harm the seals. He offered that I should bring it over for one of their mechanics to ID the fluid that is in there now.
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The gold star goes to the one guy who asked for my VIN (only one who did) and he said that my car came with the regular PS fluid, not pentosin and that I should use the same kind. $9 a bottle.

so far no issues after mixing (or possibly adding the SAME) fluid , and its been a long time , and also fixed the noise...
pheww lol




so far no issues after mixing (or possibly adding the SAME) fluid , and its been a long time , and also fixed the noise...
pheww lol




$8.70 plus tax out the door. And they even put it in a fancy tote bag like I was buying one of their fancy accessories.
Of course I snagged a bottle water and cookie while there. The car wash would have taken 30 minutes and I had somewhere to be (and maybe started to feel a little guilty).
I do owe an apology to NAPA because the fluid they showed as compatible is the same one as the one I just picked up. Every other website I checked only showed the CHF 11S. I did take a second cookie to bring to them as an apology but I ate it before I got there.









Will have to try some of the same turns this week to see if the groans are gone. And now that I have a good level, I can check for any loss in a month or so.
Will have to try some of the same turns this week to see if the groans are gone. And now that I have a good level, I can check for any loss in a month or so.
its loudest when temperatures are very hot and has continued to get louder for 2 years despite dealer visits telling me they cant replicate the sound/issue.
Here is a video of the noise - turn your volume all the way up and you can definitely hear it. When you guys had low power steering fluid did you experience noise like this? will check the fluid but am concerned its something with the steering column or steering rack????? any feedback would be hugely appreciated as i have 3 months of factory warranty left and need to get this figured out asap




its loudest when temperatures are very hot and has continued to get louder for 2 years despite dealer visits telling me they cant replicate the sound/issue.
Here is a video of the noise - turn your volume all the way up and you can definitely hear it. When you guys had low power steering fluid did you experience noise like this? will check the fluid but am concerned its something with the steering column or steering rack????? any feedback would be hugely appreciated as i have 3 months of factory warranty left and need to get this figured out asap
Thanks






