Power steering delete
Introduction
Hydraulic power steering systems continually pump fluid even when steering assist is not needed. The pump takes engine power to run and reduces efficiency.
Manual racks have no power assist, and electric racks only use electricity when you actually turn the steering wheel.
Manual steering racks have been used for many decades before power steering so the modification does mean it takes more energy to turn the wheel however the car is still drivable. The extra arm power required to turn the steering wheel wont even be noticed after driving without power steering for a few days.
Note: After this modification steering at a dead stop will be difficult therefore parking style may need to be changed a bit to compensate, slight car movement while turning will make it much easier. Steering is also easier with tires pumped up to higher than normal pressures,
Contents
Instructions for mod
For cars with hydraulically powered steering the best option for drivability and efficiency is an electric rack however the cost is very high. Drivers that are happy to use a little bit of arm strength to turn can use a manual rack which is the easiest, most efficient option and it can be a free conversion.
A hydraulically powered steering rack can be converted to a manual rack within a very small amount of time. Standard manual racks do provide slightly lower force to perform a turn due to the gearing of the rack however the difference is only around 20% gear ratio difference between a hydraulic rack compared to a manual rack. Changing out a steering rack for a manual version can take up to several days and a lot of effort for very little benefit, converting a already installed power steering rack to a manual is relatively easy and will take several hours.
To convert a hydraulic rack to a manual rack the steps are as follows
- Disconnect the hydraulic lines on the power steering rack which go to the power steering pump. Oil is likely to start coming out of the disconnected lines.
- The cylinder on the power steering rack will have a hydraulic port on either end of the rack, disconnect one of these hydraulic lines and allow some hydraulic fluid to drain out so that mostly air will be in the cylinder with a little hydraulic fluid.
- Use the existing hydraulic line connected to the other end of the cylinder and connect it to the port which is now unconnected. The ports on either end of the cylinder should now be connected together. This will allow fluid and air to flow from one side of the cylinder to the other when turning the steering wheel while keeping the hydraulic cylinder a closed system to stop contaminants fouling the cylinder.
Note: Just removing the power steering belt will stop the wasted energy using up fuel however it will cause the steering to be very heavy. For people that want to test how manual steering will feel after modification you must loop the 2 sides of the cylinder on the power steering rack otherwise every turn of the steering wheel will involve forcing hydraulic fluid through lines and back power the power steering pump which will cause much more force to turn the wheel than the proper modification.
User experiences
Please enter your user name and any relevant data in the table
| User Name | Car Make, Model, Year | Cost of Mod | Time to Perform Mod | MPG Before Mod | MPG After Mod | MPG improvement guess | Instruction Link |
|---|---|---|---|---|---|---|---|
| Saand | Mazda, 626, 1991 | $0 | 2 Hours | ||||
| Echo-Francis | Toyota Echo 2005 | $0 | 1 Min | Maybe 1% | Only removed the PS Belt | ||
| Oil Pan 4 | 1984 diesel suburban | $200+ | 6 hours | 24 | 25 | +0.8mpg | installing a P/S clutch, hydraulic power required for power brakes |
| hondaworkshop | 2000 civic | $0 | 5 Min | 2MPG | Only removed the PS Belt | ||
| Daschicken | Honda, Accord V6, 2006 | $20 | 2 Hours | Less than 1% | Installed shorter accessory belt |
I have seen testing data graphs (done by OEM's) of several cars with PS vs e-steer systems. For most cars with hydraulic power steering (PS) changing the system to electric power steering (e-steer) improves the car efficiency by 1-2MPG. This is what 5+ steering engineers explained to me was why the e-steer systems are taking over the market. It adds cost to cars but helps meet the government mandated MPG standards. I saw this data and talked this over with many engineers when I worked at a major steering systems manufacture (located in Saginaw MI).
--WeatherSpotter-9828 22:23, 7 September 2010 (EDT)
Problems / Consequences of mod
- Turning is more difficult which is mostly felt during manovering while parking, steering difficulty is not noticed after a few days with new steering.
- Turning is not really possible when your vehicle empty weight is near 3 tons. Loaded down and towing, turning at very slow speeds may not be an option with out P/S.
- Hard cornering, even at speed will take noticeably more effort versus with power steering.
References
Forum thread links
Electric Power Steering
A/C compressor clutch on a P/S pump
Power steering delete for fuel economy gain
reducing power steering pump pressure
honda civic P/S disable +2mpg
Electric power steering pump conversion
Electrohydraulic Power Steering
