Diesel tow truck power steering and braking maintenance

[Bamaman]

I recently had an O Ring blow on the power steering on my 2003 F250 7.3 diesel making me lose all fluid. Since there was already some play in the steering wheel, I chose to install a rebuilt steering gearbox ($130), power steering pump ($62) and high pressure p.s. hose ($30).

Upon further reading, I now know that diesel pickups have no vacuum to operate power brakes on. They use the power steering pump and the fluid goes through a HydroBoost system that provides braking assistance. I have read that all diesel pickups should have the power steering fluids (automatic tranny fluid) flushed approximately every 35K miles. (My truck has 135K without steering maintenance.)

My tow truck now has no play in the steering wheel, and you wouldn't believe how easy stopping the truck is after flushing the fluid and bleeding out all the air. Flushing and bleeding the HydroBoost requires two people, 1-2 quarts of automatic tranny fluid and a 6' piece of 3/8" clear vinyl tubing--and it's just a 10 minute job that's best done with the front wheels off the ground.

Everyone that's towing travel trailers or fifth wheel trailers really needs to keep their brakes, suspension and steering systems at 100% condition for safety's sake.

[steve gravelle]

Probably ATF is the proper fluid for your vehicle. However I encourage everyone to research manufacturers recommendation for exact fluid. Many specify a special fluid for their systems, and maybe any old fluid will perform the function, but when 20-30000 pounds are riding on the full function of both the steering system and brake system, why take chances? Steering and braking effort increases 5-10 times without hydraulic assist. Maybe a $10-20 difference, not worth the uncertainty IMHO!

[WhittleBurner]

Actually any fluid will brake down after extended use and needs to be serviced. Read your owners manuals to learn when different components need to be serviced.

[steve gravelle]

Great point! Not all owners manuals specify service intervals, and remember we are under the severe service operating condition. Computer based estimating systems will give you recommended time and mileage intervals.

[K&I337RLS]

I totally agree Steve & WhittleBurner.

[LCBoyer]

I read that Mercron ATF was recommended for Ford Heavy duty

[Bamaman]

Yep, the fluid in my SuperDuty power steering and HydroBoost system was automatic tranny fluid (Mercron). I was surprised how expensive the stuff has gotten @ $5.99 a quart. But it just takes 2-3 quarts.

After I drained the 135K mile OEM fluids, it was really full of metal shavings. The simple flush is not at all difficult. Changing the power steering pump and bearbox were another issue, as it requires a couple of special tools.