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How To: Power Steering/Hydro-Boost Flush

524K views 514 replies 229 participants last post by  Rex 
#1 · (Edited by Moderator)
Today, I serviced the PS/HB system with a flush; I took some pictures and thought I’d share my procedure I do regularly to prolong the life of the PS and HB units and keep them functioning properly.

ITEMS NEEDED:

  • Drain pan
  • Large channel-lock pliers
  • 5-6’ of 5/16” Fuel Line Hose (3/8" will work also, it's just what I had on hand. Clear hose to view fluid is another choice.)
  • Scrap piece of 1x6
  • Small funnel
  • 2-3 quarts p/s fluid, Just buy a Gallon Jug, it's cheaper



I'm currently using Royal Purple synthetic, but plain PS fluid is fine. I pull heavy in bad traffic and experience higher heat levels than the average user. I've experimented with a few different syn ATF with mixed results. None proved superior, some were actually detrimental to performance. Looking for a synthetic PS fluid has proven to be an elusive endeavor. At this time of edit, only RP and AmsOil offer syn ps fluid. Again, regular PS fluid is fine to use.


Here we have the culprit at hand,



CAUTION: in the picture below, you’ll see the curved metal brace coming from the cowl. I STRONGLY recommend you place a rag, towel, blanket, or some kind of cushion in this area.



(Edited with input from DF member fflmlf)
Open the PS reservoir cap to relieve any excess pressure BEFORE pulling the return line hose shown below.

When giving the final pull on the LP return hose, the release/recoil will have the underside of your wrist striking this, with potential gashes and blood spilled on your truck, resulting in you cussing me later. GrrRRrr I pull mine regularly and it comes off much easier than one that's been on for 70-80k miles.



Compressing the spring clamp,



turn the hose left and right to break the seal, then pull back off the nipple.



There will be a slight leak of fluid from the hose end when removed, so have a rag or paper towel in hand to catch it and not make a mess.

The curved end of the hose (with rag/towel over end) will hook over where the Hydro-Boost unit meets the Master Cylinder, it'll be out of your way and not leak more fluid out.


Re-using the OEM spring clamp, I secure the drain hose at the HB unit



and lay the board down to hold the hose in place with the drain pan in site from the Driver’s seat.



With the engine running and in Park, SLOWLY depress the brake pedal till it feels firm at the bottom and hold, turn the steering wheel from 12-3 o’clock and hold, release the pedal SLOWLY to the top, then bring the wheel back to 12 o’clock. Look down and you'll see the flow and then you can adjust your speed of press and release actions so as not to spray fluid out of the drain pan. It may take 2-3 times before you see the fluid start to flow.

Here we see the old, burnt, and dirty fluid beginning to flow.





.....................Continued on the next post, I'm too picture-happy to conform here.
 
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#2 ·
Good wright up!! :D



 
#3 · (Edited)
Part 2

Continue the same procedure alternately turning from 9 to 12 to 3 o’clock until you start to feel/hear the steering bind a bit, usually 4-6 pedal cycles, then turn off the engine.

Grab your funnel and refill to the bottom of the neck of the PS reservoir.



Hold up the funnel so you can see the fluid level coming up and not pour fluid all over, usually about a third of a quart at a time.




Climb back in, start ‘er up, and get after it again, repeating over and over till you see the fluid start to run clear. I know it is tempting to do but, PLEASE!, don’t leave it running while you refill the PS reservoir, the danger is too great to have your Left Arm get caught and have it get D-MAXED.

Here, we see the fluid is now running clean.




Leave the drain hose connected, check the fluid level in the pump, and fill accordingly to the Cold Line. It you over fill it, just pump the pedal a few times to drain.

Remove the drain hose, wipe the nipple clean of residual fluid, and replace the Return Line using the Spring Clip.



Start ‘er up, roll forward turning the wheel and feel the new ‘Creamy Cool Whip’ resistance in your steering, and yer ‘Good to Go’.

Consider also:
Your HB unit works in conjunction with your Brake system. Brake fluid is like a magnet for water/moisture and should be flushed annually to aid in longevity to your brake system components AND to keep the fluid's boiling point up to spec.

How To: Brake Fluid Flush

Also:
For as little as $35-ish, you can easily add a Power Steering Fluid Cooler to your HD.

How To: Add Power Steering Fluid Cooler
 
#497 ·
Continue the same procedure alternately turning from 9 to 12 to 3 o’clock until you start to feel/hear the steering bind a bit, usually 4-6 pedal cycles, then turn off the engine.



Grab your funnel and refill to the bottom of the neck of the PS reservoir.







Hold up the funnel so you can see the fluid level coming up and not pour fluid all over, usually about a third of a quart at a time.







Climb back in, start ‘er up, and get after it again, repeating over and over till you see the fluid start to run clear. I know it is tempting to do but, PLEASE!, don’t leave it running while you refill the PS reservoir, the danger is too great to have your Left Arm get caught and have it get D-MAXED.



Here, we see the fluid is now running clean.







Leave the drain hose connected, check the fluid level in the pump, and fill accordingly to the Cold Line. It you over fill it, just pump the pedal a few times to drain.



Remove the drain hose, wipe the nipple clean of residual fluid, and replace the Return Line using the Spring Clip.







Start ‘er up, roll forward turning the wheel and feel the new ‘Creamy Cool Whip’ resistance in your steering, and yer ‘Good to Go’.



Consider also:

Your HB unit works in conjunction with your Brake system. Brake fluid is like a magnet for water/moisture and should be flushed annually to aid in longevity to your brake system components AND to keep the fluid's boiling point up to spec.



http://www.duramaxforum.com/forum/how-tos-diy-write-ups/40081-how-brake-fluid-flush.html



Also:

For as little as $35-ish, you can easily add a Power Steering Fluid Cooler to your HD.



http://www.duramaxforum.com/forum/d...5850-how-add-power-steering-fluid-cooler.html
It has been probably 2 years since I've done this. Could be time. I did flush my brake fluid last month though. It was definitely time for that!

Sent from my SM-G960U using Tapatalk
 
#5 ·
It's amazing to see the junk that comes out of the bottom of the system. You'll wonder how it ever performed in that condition. :D
 
#6 ·
That's good post..pics help too

I guess mine need it,I tow some heavy loads once a week or so.Thanks for the DIY.I will flush mine now that I know how smooth it goes...THANKS:drink:drink
 
#7 ·
I guess mine need it,I tow some heavy loads once a week or so.Thanks for the DIY.I will flush mine now that I know how smooth it goes...THANKS:drink:drink
Much easier to perform than coming up with $400+ for a NEW HB unit! :D
 
#10 · (Edited)
Not sure on the miles, I don't even keep track on it anymore as my use is out of GM parameters anyway.

IIRC, under heavy use, GM suggests intervals of 20k miles. That’s a BIG guess as everyone’s definition of ‘Heavy Use’ varies as much as the Owners use varies under even more diverse conditions.

On one end is a light commuter that occasionally pulls the Bass boat out on the weekends. In between is the Owner that pulls 10k lbs, 2-3 times a week. I’m on the other end, sometimes moving 60+k lbs daily.

Add in level or hilly terrain, highway or city use, in light or heavy traffic with extended repeated heavy braking for more than an Hour, how can one pick a definitive point to schedule service?

I just look for the telltale signs of Fluid Wear for my intervals. When backing a trailer and applying the brakes while turning the wheel, you can feel and/or hear, the PS pump whine/strain and sometimes an unusual feel to the pedal also.

Many folks will drive their gassers for hundreds of thousands of miles and never think of changing their PS fluid, then seem perplexed when the unit finally gives up. :rof I have never seen or witnessed a PS pump failure in high mileage vehicles that had the fluid changed regularly.

It’s not uncommon for the HB unit to fail at 50-70k miles on many HDs that have lacked service in this area.
 
#11 ·
Update

Well, after flushing the system this weekend I also installed a set of 'Sulastic Rubber Springs'

https://www.sulastic.com

on My '05 3500, and I replaced the coupler on my GN trailer

Cushioned Gooseneck Coupler



I have to say, the combination of creamy steering and a feathered cushion ride has my dually riding and driving like an Escalade! :pimp
 
#466 ·
Well, after flushing the system this weekend I also installed a set of 'Sulastic Rubber Springs'

https://www.sulastic.com

on My '05 3500, and I replaced the coupler on my GN trailer

Cushioned Gooseneck Coupler



I have to say, the combination of creamy steering and a feathered cushion ride has my dually riding and driving like an Escalade! :pimp
Hook'em_Horns , blast from the past, but how did your Sulastic springs work out? Were you pleased / still pleased?

Thanks for the PS flush write up!
 
#12 ·
Did you buy direct from sulastic? How much trouble are they to install? Do you support the frame and let the axle fall when you install them?
 
#13 ·
Ignore the enclosed directions. Support the chassis with the rear tires off the ground, remove the Receiver Hitch and lift the axle at the differential to remove spring load. Remove the lower shackle bolts and then LIFT the axle to remove the top bolt ABOVE the frame.

There is No need to remove shocks or air springs to complete the install.

Available here:
..:: Nor Cal Truck ::.. ..:: Online Store ::..

This guy has ‘em on all four corners, impressive. The course should have him slinging around inside, yet the body stays relatively calm.
http://www.youtube.com/watch?v=NuTjZmd86js&eurl=http://www.duramaxforum.com/forum/general-discussion/8347-sulatiacs-springs.html
 
#15 ·
The cc-2 is (only) rated for 30k lbs.

 
#17 ·
Great. I've been running one since last December. A problem developed with the Rubber sleeve on the old one and they dropped shipped me a new replacement that arrived two days later, free, with return shipping included.

Standup guys that back their product. :D
 
#18 ·
Just did this power steering job today and all I can say is WOW. Thanks for the write up Hook. It was very easy following your instructions. Smooth as butter now. Mine was bad too, and low when I started so I used almost 4 quarts and still was a litle brown. Thanks again.

Brian
 
#20 ·
I just did it today after reading this, first time it had been done with 100,000 miles now. Only took me about a half hour if that other than going out and getting the fuel line and fluid. The fluid was very dark and smelled burnt, the steering definately feels alot better. The write up by Hook'em Horns was well done, thanks for the info
 
#22 ·
:thumbsup Ya'll 'er :welcome Hope the word gets out to save some members from Hydro-Boost woes. :p


Gives a new feeling to an old truck's feel. :wink
 
#24 ·
Replacement's easy, just hard on the wallet for $400.

Dealer Warranty? I would think they would flush when unit was replaced, then again, who knows.
 
#26 ·
#28 ·
The Power Steering/Hydro Boost flush was very well done!
I have a leak between HB and Master Cylinder. I'm thinking about getting a seal kit and rebuilding instead of replacing the whole unit. Anyone have a write up with pics on doing this? Info is much appreciated.

TEXAS!! FIGHT!!!
 
#29 ·
:D

I haven't even found a rebuild kit available. It may not be worth your time, as here is a $ource for only

OUR PRICE: $274.61
GM LIST: $527.91
GM PART # 15854059
CATEGORY: All
PACK QTY: 1
CORE CHARGE: $0.00

GM Parts Direct: Your direct source for Genuine GM Parts

Don't wait too long, that fluid will eat off all of the undercarriage coatings that it comes in contact with. :cool

 
#33 ·
Hookem,I just flushed my hb unit this morning and used the Dec VI fluid. I tow pretty heavy and was wondering if you noticed if it lasted longer than reg ps fluid.
 
#34 ·
Yes, it has held up better. I'm going to try a switch to syn PS fluid as a member sourced NAPA as stocking a Valvoline synPS fluid. Just called and they're going to order it, be here tomorrow. $4 something instead of $6 something for DEX-VI.

Rumored also that GM parts has one for a SAAB exclusive use, but that's probably mas Dinero$.
 
#37 ·
Well, that was a no go. I couldn't find the product on the Valvoline site any longer. Come to find out they have a new part number in place of the old for SynPower, which in reality is just plain PS fluid. It's been discontinued. So, the search is still on. Some had suggested the product for SAABs in a green can, but this is NOT a synthetic fluid.

Royal purple is available for just under $5 for 12oz., not in my price range. :p
 
#38 ·
No. Simple stuff, requiring about 30 minutes. Remove the two nuts from the studs connecting to the Master Cylinder, and move forward out of your way. DO NOT remove any brake lines or open the brake system in any way.

Remove the threaded couplings for the high-pressure lines and remove the clamped-on low pressure return line.

On the inside, remove the keeper connecting the push rod to the brake pedal. Remove the 4 nuts from the studs on the HB unit, I recommend a boxed end swivel head ratchet wrench.

Pull the unit forward to remove, and then work in reverse to install the new unit.

Hook up the lines, start the motor and cycle through as described in the flush instructions by moving the wheel left and right while depressing the brake pedal. The unit is self-priming, so kill the engine, and check your PS fluid levels to add back what the new unit displaced in fluid, and you’re good to go. :thumbsup
 
#39 ·
Cool, Thanks.
Just one dumb question so I am clear. Is it supposed to be dry where the HB and MasterCylinder connect (no fluid)? Becuase that seems to be the place it is leaking from but I could be wrong about that. I was wondering about a gasket becuase I was under the impression that there was fluid under pressure at that connection.
 
#40 ·
Not dumb, just a logical conclusion, viewing two units joined together.

Here is a pic, (I like pics :D)


Recessed in the unit body at that connection is the seal for the piston rod, which is worn, leaking and seeping through that connection.
 
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