Results 1 to 6 of 6

Thread: '94+ bird power steering pump.....

  1. #1
    Join Date
    Sep 2002
    Location
    SE CT
    Posts
    715

    '94+ bird power steering pump.....

    Do the '94+ birds (or M VII's) have power steering pumps have a remote resivoir?

  2. #2
    Join Date
    Feb 2003
    Location
    Tinton Falls, NJ
    Posts
    1,488
    4.6 powered birds and markviii's have the remote reservoir pump. SCs and 3.8na birds have the style with the integrated reservoir.

  3. #3
    Join Date
    Sep 2002
    Location
    SE CT
    Posts
    715
    Quote Originally Posted by MadMikeyL View Post
    4.6 powered birds and markviii's have the remote reservoir pump. SCs and 3.8na birds have the style with the integrated reservoir.
    Thanks, that makes it easier to ask to look at one at the local parts store.
    Next Q's, do any of those have EVO? Does it mount to the PS pump same as the SC?

    I got home tonight and pulled the EVO off of an SC PS pump. I noticed that the male part that screws into the pump body has what looks to be a bleed hole between the threads and the first O ring. There also appears to be a passage in the pump outlet that matches up with the hole. Q, does this passage bleed back to the reservoir through the pump body? Am working on my BBF swap into my '93 SC and trying to plan my parts, budget/timeline. Planning on going Hydro-Boost and want to keep my VAPS and the remote res. pumps don't take a lot of room on the front of the engine. A/C and Alt are are going to be fun also.
    MikeH

  4. #4
    Join Date
    Dec 2007
    Location
    Salem, OR
    Posts
    6,289
    From the service manual:

    The EVO system is designed to vary the flow from the power steering pump as a function of vehicle speed and steering wheel rate of rotation, giving a form of variable assist. The system provides full power steering assist at low vehicle speed for light parking effort, and minimum assist at hight speed for good 'road feel' and directional stability. Full assist is returned during evasive maneuvers.
    The speed sensor at the trans and steering wheel optical rotation sensor communicate to the control module in the package tray in the trunk, which activates the EVO valve in the power steering pump. The EVO valve is a stepped piston that pushes against a spring and is moved by applying current to the coil in the body, much like a starter solenoid. As the control valve moves in/out it allows fluid pressure to bleed off and present lower pressure out to the steering rack or to remain high as needed.

    Vehicle Speed Sensor:
    The vehicle speed sensor, also used for adaptive suspension, is located on the transmission and is used to establish the vehicle speed. The output current to the actuator is a function of the vehicle speed and steering wheel rotation rate. When the vehicle speed is 5 MPH or less, the output current is 0 mA, and full power steering assist is provided. As the vehicle speed increases to 20 MPH, the current increases linearly to 225mA. As the vehicle speed continues to increase up to 80 MPH, the current increases linearly to 550mA. The current then remains constant at 550mA for vehicle speeds above 80 MPH. Conversely, as vehicle speed decreases, the current decreases at the linearly rate.
    Last edited by KMT; 07-03-2014 at 01:27 AM. Reason: added info

  5. #5
    Join Date
    Sep 2002
    Location
    SE CT
    Posts
    715
    Sorry, but this calls for more than a basic 'One line diagram' overview. Been reading tech/repair manuals for a living 35+ years now. Just haven't got a handy dandy manufacturer's pump tech pub in my library, yet.
    Need to figure out how to get fluid from the pump to the hydro boost unit at all speeds WITH OUT being restricted by the EVO as the vehicle increases speed. So, it looks like: 1)A fitting to take the place of the EVO on the pump outlet. 2)A 'T' fitting to feed both the hydro unit and 3) An female inline piece to accept the EVO so that VAPS still functions. 4)Hoses to connect Pump, Hydro Boost unit, remote reservoir, Steering Rack and cooler.
    This is where the need for information about the fluid dynamics between the pump and EVO when the Actuator changes the flow rate through the steering rack. Can a straight in/out in-line type fitting be used to place the EVO in line with the Rack? Or, does it need a bleed path to function correctly?

  6. #6
    Join Date
    Dec 2007
    Location
    Salem, OR
    Posts
    6,289
    So you want to combine these two systems?




    -=-=-



    In that example, I would delete the EVO from the pump and come straight off with an applicable fitting.
    Last edited by KMT; 07-03-2014 at 11:10 AM.

Similar Threads

  1. alternator or power steering pump?
    By marrart in forum Technical Forum
    Replies: 1
    Last Post: 05-03-2003, 04:27 PM
  2. power steering pump locked up at 6,000 rpm
    By mannysc in forum Technical Forum
    Replies: 2
    Last Post: 03-24-2003, 12:20 AM
  3. Need new power steering pump!?
    By Hellraizer547 in forum Technical Forum
    Replies: 0
    Last Post: 03-12-2003, 01:01 AM
  4. Does anyone make a "quiet" power steering pump for our SC's?
    By phils89sc in forum Technical Forum
    Replies: 28
    Last Post: 01-23-2003, 02:42 PM
  5. Power steering pump wont stop leaking!
    By bigcletus94 in forum Technical Forum
    Replies: 2
    Last Post: 01-19-2003, 05:08 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •