DIY: Refresh your Power Steering Reservoir/Hoses, for 10 Bucks

[Ricky Bobby]

Note: This only applies to vehicles where you are sure the PS reservoir has no cracks, and the hoses are in good shape from what I have gathered it is a pretty stout piece, and isn't prone to cracking like our expansion tanks. Most replace them because they are cheap comparatively, at 40 bucks for Genuine BMW, or ZF (OEM) for around 25 bucks. My 2003 has 71k miles and the reservoir is basically brand new, hoses going from the reservoir look good as well, not dried out or cracking. This DIY is performed on a 3.0 M54, but process is similar for V8 models. Obviously I am not liable for any damages to your vehicle when following this procedure.

You will need:

1 - Quart of Synthetic ATF (PS fluid, I used Mobil 1) or if your cap says CH-11S on it, use that ($5.99 for Mobil 1 ATF at WalMart)

1 - Size -130 O-ring, pick your poison as far as material goes, personally I used a Fluorosilicone O-ring (military rated, higher temp and chemical resistance than Viton, and its blue! lol) from McMaster Carr, $3.50

2 - Stainless Steel worm drive hose clamps, I forget the sizes but somewhere in the 7/8" range, just measure the diameter of the hoses first, if you prefer your clamps not to "bite" into the hose you can use fuel line clamps which are smooth inside

Tools:
-Utility knife or PVC pipe cutter (great for hose trimming)
-Socket driver or screwdriver for hose clamps
-Turkey baster or siphon for draining reservoir
-Socket for mounting bolts of PS reservoir
-Drip bottle for catching old fluid


1) Open the PS cap, remove o-ring by picking it out with a small knife or screwdriver, throw old o-ring in trash, lubricate new o-ring with fresh ATF or CH-11S, install on cap in groove, set aside for later.

2) Take your turkey baster ($1 at dollar store, then you can throw away after and your wife won't get mad), suck out all fluid in reservoir

3) Unbolt reservoir off its mount, now you have some room to work

4) Use flathead to loosen clamps on bottom of reservoir, place drip bottle underneath, and remove hoses from reservoir 1 at a time, catching the drippings from the reservoir into your catch bottle, and draining the fluid from top of the hose, remove old clamps from PS reservoir hoses

5) Take pipe cutter or utility knife and cut approx 1/2" off the ends of the hoses, make a clean cut and expose a fresh hose end, slide new worm gear clamps over hoses

Optional Step from Miniz Guy if you'd like to replace your hoses but don't want to buy factory ones for $60:

On E36's, the hoses are 1/2" ID. Use transmission hose rated for high pressure applications and you can replace the original hoses for about $10. Cut the original crimp off, but not into the barb, and slip the new hose on with another worm clamp.

The process should be the same on the X5. A little better way that using the old hoses.

6) Reconnect hoses to bottom of reservoir (they are different sizes so you can't mix up), tighten clamps with screwdriver or socket, now is a good time to wipe down the 2 hoses with degreaser, and use a rubber protectant on them, I use 303 Aerospace protectant on rubber items

7) Bolt up reservoir back to its mount next to the Oil filter housing (on 3.0 models), and refill with fresh ATF. There is a dipstick on the cap which has a clear marking for the correct level, don't overfill. Put your cap with new o-ring on the reservoir and check level.

8) Start car, do a couple lock to lock turns, then shut car off and check level on dipstick. Remove some fluid with siphon if too high, add some if level shows low. Obviously check for leaks on bottom of reservoir, but as long as hoses were in good shape, you should have none as long as you exposed a fresh hose end and used new clamps

10) Have a brewski and enjoy not having to mess around with your PS system for a few years!


I have to give credit to bluebee and others at Bimmerfest for the O-ring sizing on the reservoir, this DIY is inspired by their threads and helpful information on the M54 engine, and I thought I'd pass along the information to my fellow Xoutposters, with some preventative maintenance and inspection, a half hour of your time and about $10 in materials, this is an easy procedure to perform if you are doing an oil change or something similar. Hope this is helpful to some!

[mam4.6]

A+ for preventative!!

[JCL]

Isn't the reason to replace the reservoir that it includes a non-replaceable filter?

[tmv]

[Ricky Bobby]

Originally Posted by JCL

Isn't the reason to replace the reservoir that it includes a non-replaceable filter?

The filter is non-replaceable, but it is cleanable. Its basically a fine screen.

If you wanted to run some gas or other cleaning liquid through it in order to flush the screen of any trapped contaminants, you could do so, and secure the filter and probably have more life out of it.

You could buy a replacement reservoir for 25 bucks, use the O-ring size I listed (slightly thicker than stock for a better seal, and better material if using fluorosilicone), and then you would have a refreshed PS system for $40 instead of the $10 I listed in the title, lol!

Here is a reference from Bimmerfest on cleaning the filter inside the reservoir at the time of this, which would keep the "refreshment cost" at $10 still, I would obviously clean out the reservoir/filter with gasoline when it is disconnected from the car, don't want any going down the hoses!

- Power steering: Dexron III ATF Bentley page 020-20. (realistically, that means Dexron VI ATF because all GM Dexron III licenses expired at the end of 2006 & were not renewed by GM). Replacement Interval: Bentley says it's "permanently filled"; but most of us would replace the hygroscopic power steering fluid at 30,000 miles; some recommend removing the 8 ounces (250 ml) in the reservoir at every oil change - and removing the T20 Torx bolt on the permanent reservoir screen every 5 years to clean the circular filter more thoroughly to prevent cavitation - and to replace the power steering cap o-ring every five years to prevent misting. [Volume: about 2 quarts to replace; otherwise about 1 quart to flush the reservoir twice & clean the filter screen; the fluid level should be between the MIN/MAX marks on the dipstick].

Personally I'd just take the extra few mins to flush the screen out when doing this service, as it's pretty easy (just don't drop the T20 screw securing the filter, lol!)

[MINIz guy]

On E36's, the hoses are 1/2" ID. Use transmission hose rated for high pressure applications and you can replace the original hoses for about $10. Cut the original crimp off, but not into the barb, and slip the new hose on with another worm clamp.

The process should be the same on the X5. A little better way that using the old hoses.

Sent from my SAMSUNG-SGH-I537 using Tapatalk

[Ricky Bobby]

Originally Posted by MINIz guy

On E36's, the hoses are 1/2" ID. Use transmission hose rated for high pressure applications and you can replace the original hoses for about $10. Cut the original crimp off, but not into the barb, and slip the new hose on with another worm clamp.

The process should be the same on the X5. A little better way that using the old hoses.

Sent from my SAMSUNG-SGH-I537 using Tapatalk

Nice and thank you miniz for the contribution, I will add that to the top of the thread!

[Doru]

I used to do this 1/2" cut as well, but this will last for only so long. I am not sure what the OEM rubber is made of, but once it start changing form (expanding), the end of the hose is near.
The first sign is that slow seep at the clamp level - fixed in Ricky Bobby's DIY by cutting the 1/2". The 2nd sign is when these hoses start to sweat the ATF through. In my case, the "fix" lasted less than 1 year, after which I changed the hoses altogether.

Another aspect of the equation is the fact that there might be a flow restrictor in the feed line (I am not 100% sure about this, but I did some reading, and one can experiment trying to flush the ATF - take the reservoir off, you will have 2 open ended hoses, one should go in an empty jug, the other in a fresh jug with ATF - if you are not careful, i.e turning the steering wheel too fast, you will empty the feeding jug in seconds and suck in air - the jug to be filled will fill also in seconds and will overflow - hence the need for a "controlled" flow in the steering lines). That restrictor has also the role to guide the PS hose(s).

just my 0.2

[Ricky Bobby]

Thanks Dorin, as always valuable knowledge. This "refresh" is only recommended for cars with lower mileage, hoses still in good shape, etc. In my case, my hoses are still black in color, as you mentioned in our conversation a good tell tale sign when you see hoses and plastic parts turning brown, they are at the end of their service life and should be replaced.

[Brandon002]

This DIY wouldn't be a "refresh" more like a quick fix for a leak.