How to: Power Steering Flush (Video)

Thanks for that video A/Ox4! Had seen a writeup on this, but the video persuaded me to do this sooner rather than laterm i.e., TODAY!

Prepared by calibrating a 1 1/2 gal vinegar bottle in 16 oz increments as a capture container to measure what came out so I knew what had to go back in. Was hoping to flush 6 qts. My system had not been flushed at all in 94K miles. Have owned this truck 13 yrs and it just started groaning over the last year.

All I had was a 10' length of 5/16” ID x 10' clear vinyl tubing. Got it to work by putting one end in hot water and inserted needle nose pliers to spread the opening. It slipped over the nipple easily and it gripped tightly without a clamp. I decided to flush w/o raising the front wheels off of the ground because we have soft soil out here and I didn't have anything available to support the feet of 2 jack stands. Probably should have figured a way to do it.

I usually start out with (nitrile) gloves. It is a given that at some point, they come off and stay off, but I keep trying.

This did not go as smooth for me as in the video. The video clearly warned against getting air into the system and thought replenishing the reservoir at ~4oz at a time would work. All started well with the fluid coming out dark. After what seemed like seconds of my helper turning the steering and pumping the brake, the fluid in the tube started to turn pink and foamy. The pump started groaning. Shut it down to check fluid and it was below the cold fill mark.

Replenished and tried again, replenishing at a faster rate, but was having a real hard time. Eventually the steering wheel wouldn't budge and we couldn't go any further than 2 qts. Shut it down and decided to do an online search for solutions. A good sign was that the foam seemed to dissipate in the tube and expect the same was happening in the system.

My biggest concern was possible damage to the hydroboost and/or the pump. Another diesel forum had 2 solutions: 1) keep checking the level and drive it until it purges and 2) a procedure for bleeding the system. Chose #2.

The procedure basically was to vent the filler opening by sealing it with a rubber glove with a small hole in one of the fingers to prevent getting fluid all over the place but allowing air to vent while turning the wheel lock to lock at least 25 times and maybe as much as 60 times The glove seemed unnecessary because the cap looked vented to me, but used the glove as described, anyway. Was real careful not to drop the rubber band inside to add to my problem!!!

It was nearly impossible to move the steering wheel without great force or moving the truck and it groaned fiercely. Would muscle the steering wheel while slowly moving the truck in “S” turns in forward and in reverse making sure to do full lock to lock turns. After a few turns, would shut it down and check the reservoir level. Each time the level went below the cold fill mark. Continued to replenish as necessary and repeated lock to lock turns at least 80 times. Throughout this procedure, it slowly came back to normal operation.

Shut it down several times over a few hours and let it cool, checked level and let it sit, then go back out and repeat. It kept getting easier and finally reached a point where operation was silky smooth except for a pump protest at extreme lock or hitting the brake pedal.

Overall, it finally got back to the way it should be. It has definitely improved over the pre-flush condition, but I was really concerned.

While searching for a solution to my foaming problem, it was recommended in the other forum to NEVER start this flushing process when the fluid is HOT. It should be started when the truck is COLD. Couldn't see any explanation why. Anybody have any ideas? Hope there is an answer out there for that.

Normally after such an experience, I have a recommendation or two to prevent problems I encounter. Can't say I can prevent the foaming from occurring again. However, I would at least recommend that you start with a cold truck and make sure the reservoir is at the COLD FULL level on the cap's dipstick. The trickiest part of this procedure is getting a feel for the rate to replenish the reservoir as the old fluid is being purged. I thought I was even a little ahead of the purge rate, but apparently wasn't. At one point, shut down and extracted some fluid because I got too far ahead of it.

Once air is in the system, things might get worse before you can make them better. If you can get your front wheels off of the ground, that will very likely make the flush a lot easier, especially if this is your first flush experience. You'll be better prepared to purge the system if you get air in it, too .

While things seem to better than before I started, it is unknown if there is any damage to the hydroboost or the p/s pump. I wanted to flush 6 qts to really make sure it was clean. I stopped at ~2 1/2 plus whatever I added a few ounces at a time over the next few hours. Will keep an eye on this and maybe give it another go later.

I can't fault the video. Somewhere, I got probably got behind the purge rate. If anybody has any ideas where it went wrong for me, I'm all eyes and ears.

This almost made me think twice about attempting Mark Kovalsky's ATF flush procedure. The good news is that you WANT bubbles showing up at a certain point in his procedure!