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How-To: Flush Hydroboost System

PostPosted: May 30 2020, 10:04pm
by 19trax95
I intend this write up to be simple, and to the point.

I will show how to flush the old, often neglected, power steering fluid that is used for the trucks with the Hydroboost braking systems.

This will replace all your old fluid, as well as help to flush and crud that may have built up in the system.

Tools needed:
-Hose pinch pliers (optional)
-Spring clamp pliers (optional, regular pliers will work)
-small funnel (again, optional but depending on the fluid you get, it may be needed)
https://i.imgur.com/WcPtujo.jpg

Supplies needed:
-Power steering fluid. (It took me just under a gallon, so I recommend getting a gallons worth)
-Approximately 6 feet of 3/8" rubber hose
-Bucket or drain pan
-Rags

Step 1:
Using the hose pinch pliers, crimp off the return line on the Hydroboost unit mounted behind the master cylinder. This is the small 3/8" rubber line held on with a spring clamp. You will still have some fluid leak out of the fitting so have a rag under it to stop it. Now move that line off to the side. You can take the clamp off and use it in the next step, or use a worm drive clamp. https://i.imgur.com/KrybPm2.jpg

Step 2:
Install your rubber hose on the fitting and clamp it. You can use the factory spring clamp or a worm drive. Either will work find for this job as there isnt much pressure there. Route this hose into a bucket or drain pan. Again, there isnt much pressure here, but there is some, so make sure it cant flop out of the bucket. https://i.imgur.com/VXQilFJ.jpg

Step 3:
Remove the cap from the reservoir and take note of the color and level of the fluid. Now here comes the important parts. Start the truck and slightly tuen your steering wheel. Go just until you hear the pump working a bit, and hold it there. Now, slowly but firmly press down on the brake pedal and release. It will take a pump or two until fluid will begin to come out. Keep the wheel held and slowly press and release the brake about 5 times.

Try not to let the reservoir run empty, so after 5 presses of the brake pedal, use your new fluid and top off the reservoir. Now repeat the holding of the steering wheel and pressing of the brake, filling the reservoir and repeat until you see nothing but new, clean fluid coming out of your hose. https://i.imgur.com/3dzgCZh.jpg https://i.imgur.com/MFyBGAQ.jpg

Step 4:
Now that you have clean fluid throughout the system, shut the truck off and remove your drain hose. There again will be aoke fluid that will come out. Install the factory return hose and clamp. Un-pinch the line and bring the reservoir up to the full mark on the dip stick. Start the truck up and turn the wheel back and forth and pump the brakes. This will make sure no air is in the system.
https://i.imgur.com/9EU4KML.jpg
Step 5:
Do a final level check and clean up any spills you may have made, and enjoy the smoother feeling steering and know you just did what most people neglect. Now is also a great time to change the brake fluid.

Sent from my SM-N960U using Tapatalk

Re: How-To: Flush Hydroboost System

PostPosted: May 31 2020, 4:01pm
by Walkers
Nice write up. Just FYI, you dont need to crimp off the return line. There is no pressure on it, just keep the end above the level of the PS reservoir.

Re: How-To: Flush Hydroboost System

PostPosted: May 31 2020, 4:10pm
by 19trax95
Yup. I do it just to help limit the amount of spilled fluid when removing the line. Helps keep things cleaner.

Sent from my SM-N960U using Tapatalk

Re: How-To: Flush Hydroboost System

PostPosted: Jun 05 2020, 5:38pm
by Bradley21sanders
Nice, I wish more people did detailed writeups on stuff just because its neat to see/learn stuff.

In your opinion, is this something that someone should do every year or every 5 years or?

Re: How-To: Flush Hydroboost System

PostPosted: Jun 05 2020, 5:48pm
by 19trax95
I would say yes. Just like brake fluid, crud builds up and the fluid gets nasty.

Its one of those things that all too often gets neglected. I'd say coolant, power steering fluid and brake fluid are the 3 most neglected fluids.

Re: How-To: Flush Hydroboost System

PostPosted: May 12 2021, 5:17am
by tinner
19trax95 wrote: Its one of those things that all too often gets neglected. I'd say coolant, power steering fluid and brake fluid are the 3 most neglected fluids.


I agree, was changing brake fluid and power steering fluid on my 2000 1500 a few years back when a friend came over and his first words were, "Having brake problems?" I said, "No and I don't want too either."

Re: How-To: Flush Hydroboost System

PostPosted: May 31 2021, 5:50pm
by silentbravo
19trax95 wrote:I would say yes. Just like brake fluid, crud builds up and the fluid gets nasty.

Its one of those things that all too often gets neglected. I'd say coolant, power steering fluid and brake fluid are the 3 most neglected fluids.


And rear differentials. Like come on, who actually changes that fluid? :lol:

Anyway, Thanks for writeup, just changed mine (well still have the cleanup and bleeding part). If the pump doesn't get a bit quieter I guess that will be on the list for replacement....