Power Steering Reservoir question

[ProfessorX5]

Getting ready to order the part, since I've got a slow seep, but Seeing something on websites that I don't quite understand:

Product Notes: NOTE : BMW has replaced ATF P/S Reservoirs w/ CHF 11S reservoirs. Replace fluid accordingly. Includes non-serviceable filter.

What's this mean? Will I have to go with Pentosin hydraulic fluid rather than ATF?

I only see this note on ZF reservoirs. The listing for a Dorman reservoir doesn't say anything of the sort. I'd like to keep things simple :P

Also, any quality difference between the two brands?

[BMWX5CHI]

Are you sure your reservoir is leaking ? Mine was leaking and turned out it was all of the clamps on the hoses. Over time those German style clamps get loose and cause ATF to seep out. I replaced all of the hose clamps, drained and removed all the old fluid with a siphon pump, cleaned and reused the reservoir since it was still in great shape. May not be the your case but doesn't hurt to look and see.

[Qsilver7]

Originally Posted by ProfessorX5

....something on websites that I don't quite understand:

Product Notes: NOTE : BMW has replaced ATF P/S Reservoirs w/ CHF 11S reservoirs. Replace fluid accordingly. Includes non-serviceable filter.

What's this mean? Will I have to go with Pentosin hydraulic fluid rather than ATF?

As stated...BMW used to have 2 different style of PS reservoirs...the small black plastic type with a lid that had an incorporated dip stick built-in & used with ATF fluid...and the larger reservoir used in the models that had rear SLS & that used Pentosin.

Well, they stopped making the small black reservoirs...which only leaves the taller type...but you DO NOT have to start using Pentosin...continue to use the fluid your car came with (aka "replace as accordingly").

They also sell a sticker that you need to order, too that indicates which fluid you should use in the PS reservoir...especially if your car uses ATF...because if you get the replacement CHF reservoir...the new lid may have that information engraved into it...and the next owner or shop will be confused as to what fluid is in the PS reservoir and may put the wrong fluid in (which is NOT a good thing).

You can see the 2 types of reservoirs in the image below from the e38 owners manual...again, the smaller ATF reservoir (on theleft) is no longer available...which now forces owners to substitute the CHF reservoir since all the hose fittings & mounting points etc are the same:

Since there's no dip stick to the CHF PS reservoir...I guess we can assume to fill it to the same level with ATF as it would be filled with Pentosin?

[ProfessorX5]

Aha! Thanks, I feel slightly less cartarded now

[Ricky Bobby]

I bought this ZHF reservoir over winter and it doesn't show on the cap what fluid, however, I know its ATF since it says so on my stock cap.



You could swap caps on the new reservoir to keep the indication of fluid present, or maybe mark with white out somewhere on the reservoir "ATF" to help future owners.

Personally I just swapped reservoirs and refilled with fresh ATF as I'm well aware mine wasn't taking CH-11ES.

[mferek]

I just bought a new PS reservoir (same as the one pictured is Ricky Bobby's pose) last week, so they're definitely still available. Got it from Pelican Parts.