2000 Ford Diesel Superduty
Hydraulic System Filtration

I feel that the cleaner I keep my hydraulic fluid, the longer my power steering and hydroboost components will last. To accomplish this, I installed an in-line filter into the hydroboost low-pressure return line. 

I decided to do this after seeing the inside of my transmission pan after installing a similar filter in the cooler lines for that system. The last time I dropped the transmission pan, it was SPOTLESS inside after 45,000 miles on the oil! A great Blackstone Laboratories oil analysis confirmed the filter's value.


From a steel supply company:
4" x 4" x 1/4" "gussett plate"

From auto-parts store:
1 ea - 3/4-16 spin-on filter base (TransDapt #1028 or equiv)
1 ea - BT111 Baldwin filter (or equivilant)
20 ft - 3/8" transmission fluid rated hose (AutoZone 81352, $2.49/ft.)
1 ea - small tube of Loctite thread sealant
4 ea - small fuel-line-size stainless screw-type hose clamps
2 ea - 3/8" x 1/2" NPT brass "thread bushings"
2 ea - 3/8" NPT right-angle brass hose fittings to fit 3/8" I.D. hose
1 ea - 6" of 4.8mm SAE 30R7 small fuel line

From the hardware store:
4 ea - 5/16-18 x 3/4" grade 8 bolts, will be trimmed to custom lengths later
1 ea - 5/16-18 x 1-1/4" grade 8 bolt
1 ea - 5/16-18 grade 8 nut
6 ea - 5/16 grade 8 flat washers
Plastic wire-loom to cover hoses for abrasion protection
Wire ties as necessary

(Click on any photo below to enlarge it)

Prepping the Parts

This drawing is used to lay out the holes on the 1/4" plate (click to enlarge most photos).  Note I turned it to a 45-degree angle to allow stuff to slide off easier, but it's not necessary.
The plate is a piece of 4" x 4" x 1/4" mild steel "gusset" stock from a local steel supplier.  It could be thicker, but it's not necessary, as there is plenty of thickness for threads.
Note that the lower four holes are first drilled to 9/32" then threaded to 5/16-18, and the upper-most is a through-hole of 5/16".
Due to the center-to-center distance between the threaded ports on the top of the filter base, a portion of one of the hose "nipples" must be shortened.  Easy if you have a disk-sander.
The filter base is a standard spin-on base with 3/4-16 threads.
Note one shorter nipple. Use LocTite on threads.
This is why one nipple needs to be shortened.
Due to four of the the mounting bolts coming into the plate from different sides, and something being in the way past the plate, the bolts must be custon-sized to length.  Two of mine are now
5/16-18 x .525", and two are 5/16-18 x .625" long.
Though these look rusty, they are primered.

Where I Mounted It

This location is on the outside of the driver's-side frame rail, above the rear edge of the transfer case cross-member.  I used this because of the existing group of three holes (circled in chalk).  I do not like drilling holes in my frame, and thus far have never had to.

This is the filter base when mounted on the frame. I used a coating of RTV between the frame and the plate, and between the plate and the base.  This is to avoid a place for water and mud to gather, thus a place for rust to begin. I was careful to keep RTV out of the threaded holes, and they are sealed with the use of LocTite on the bolts. Notice the small piece of split fuel line over the parking brake cable to prevent abrasion and rattling.

Here is the Baldwin BT111 mounted to the base.  Just out of this picture the hoses begin to be covered with plastic split-loom for abrasion resistance.

Tapping into the Hydraulic System

This is where I "tapped in" to the return line to add the external spin-on filter. The factory hose in place there is completely removed. You can figure out the hose routing down to the filter. Use the proper hose, rated for ATF! The hose I bought says "Gates 3/8" (9.5mm) CPE HIGH TEMPERATURE POWER STEERING RETURN LINE HOSE" and is AutoZone Duralast p/n 81352.

This is where the fluid is returned from the filter to the pump reservoir. Securely clamp all the hoses using small stainless screw-clamps, and add plastic split-loom for extra abrasion resistance.

The Filter


I use Baldwin filters as I believe them to be the best on the market. The BT111 is for hydraulic filtration applications, and has a built-in 20-PSI bypass valve.  You could use a B2 (or even a Motorcraft FL-1A) with an 8-PSI bypass valve if you couldn't find the BT111's.





Small neodymium magnets, attached to the filter base plate on the inlet side, collect magnetic sludge the same as the magnet in the trans pan. It's better to collect it, and it's easy to clean off every time you change filters, but this is optional. I've shown small, rectangular ones, and you'll only need a couple of them. They're available from All Electronics, www.allelectronics.com as part number MAG-74. They're fifty cents a piece, so get a few. You'll use them on your refrigerator door, too.

Be prepared to "top off" the system a few times over the next few days as air gets worked completely out of the system. You'll know it needs additional fluid when you hear that familiar low-fluid "pump whine".

The filter should get changed initially at about 5000 miles, then every 15-20,000, unless you implement this addition at the same time you do a complete fluid change. Then you could likely go 15,000 miles on the first filter. Be sure to clean and re-use the magnets, too, if you used them.

Does it Work?

I don't know yet. I own this truck for "the long run", so I'm going to find out! I'm installing this with 195,000 on the "clock", and I'll see how much longer I can extend the power steering pump, steering box, and hydroboost units, all of which still operate perfectly at this time using synthetic ATF in the system.

Edit 22JUN19: Now with 270,000+ miles. So far, so good....

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write: SpringerPop

Last updated 03/19/11