No Power Steering

[captinsho]

My timing belt went out on me last week. I replaced it last night and the job went well. However now for some reason I have no power steering. I did intentionally disconnect any power steering mechanisms and the belt is on the pump and seems to be turning it fine. Does anyone have any idea why my power steering would not function? Maybe some trouble shooting tips.

 

[projectSHO89]

You didn't mention if you checked the fluid level.

It also helps if you identify the year, engine, and transmission of your car. We are not psychic.

Did you move the PS reservoir out of the way to work on the belt? If so, you may have kinked the supply hose from the reservoir to the pump.

With the engine idling and the fluid at the correct level, observe the fluid in the reservoir eith the cap removed. If it is moving, my best guess would be the rack. If it is not moving, look at the pump or the pump pulley/shaft.

Steve

 

[captinsho]

Sorry I missed the year/tranny info. I am running on about 4 hours of sleep for the last two nights and my brain is hardly functioning. The car is a 94 MTX. I did not move the resevoir. The long story is that I did the job last week (crank pos. sensor) and drove the car and everything including the power steering worked fine. SOMEHOW my belt slipped. I must not have had the tensioner in the right position. I have done a timing belt on it before and had most of the same area apart for a water pump replacement and never had power steering problems. It is possible that the power steering pump went bad but it just seems like too much of a coincidence seeing as it worked fine until I did the timing belt again last night. I will try your tips and I do appreciate them. If anyone else has any ideas pass them my way. Is is possible I disonnected a wiring connection or would that not affect power steering?

 

[projectSHO89]

The PS system is totally hydraulic unless it has VAPS. If it has VAPS, it is conceivable that the VAPS system has forced the system into the lowest boost condition or is otherwise interfering with the hydraulic system.

Steve

 

[captinsho]

Okay you might have to treat me like a 2 year old here but I just want to make sure I am understanding you correctly. When you say VAPS I am assuming that means vacuum assisted power steering, correct? If that is the case how would I check for a low boost condition?

 

[projectSHO89]

My apologies for this curt reply, but I do not have sufficent time to go into detail at this moment.

You can research VAPS (Variable Assist Power Steering) by performing a Google search on "Ford VAPS" There are multiple hits that will give you some ideas as to how it works.

Here is the roubleshooting section from th 93 service CD for vehicles WITH VAPS:

NOTE:
The following diagnosis chart applies to a variable assist steering system.


STEERING SYSTEM DIAGNOSIS

Condition(s):
o High (Excessive) Steering Gear Efforts at All Vehicle Speeds is a Condition Recognized While Turning Corners and During Low Speed Maneuvers and Especially While Parking. The Assist Concerns May Occur in Both Directions or Only in One Direction, They May be Intermittent, or Consistent.
NOTE:
Discolored steering fluid in a rack-and-pinion steering system should not be misdiagnosed as a functional or noise concern.

Possible Source(s):
§ Low pump fluid.

Action(s) to Take:
§ Fill as required and check for system leaks.

Possible Source(s):
§ Gear assembly external or internal leak.

Action(s) to Take:
§ Replace steering gear assembly. Refer to «Section 11-02».

Possible Source(s):
§ Pump external leak.

Action(s) to Take:
§ Refer to «Section 11-02».

Possible Source(s):
§ Pump pressure and flow improper.

Action(s) to Take:
§ Perform «Pump Flow and Relief Pressure Tests» . Service as required.

Possible Source(s):
§ VAPS (Variable Assist Power Steering) system malfunction.

Action(s) to Take:
§ Refer to VAPS system diagnostic procedure in «Section 11-02».

Possible Source(s):
§ Improper drive belt tension.

Action(s) to Take:
§ Check for proper belt tension.

Possible Source(s):
§ Hose external leak.

Action(s) to Take:
§ Service or replace as necessary.

Possible Source(s):
§ Hose restriction.

Action(s) to Take:
§ Clean and replace as necessary.

Possible Source(s):
§ Pump pulley loose/warped.

Action(s) to Take:
§ Replace pulley. Refer to «Section 11-02».

Possible Source(s):
§ Power steering pump belt loose/glazed/broken or water on belt.

Action(s) to Take:
§ Inspect, adjust belt tension or replace as required.

Possible Source(s):
§ Engine idle too low.

Action(s) to Take:
§ Adjust idle.

Possible Source(s):
§ Tires not properly inflated.

Action(s) to Take:
§ Inflate.

Possible Source(s):
§ Suspension bent or interference.

Action(s) to Take:
§ Inspect service or replace as necessary. Refer to «Section 04-00».

Possible Source(s):
§ System contaminated.

Action(s) to Take:
§ Inspect system for foreign object, kinked hose, etc.
-- Flush system
-- Refer to power steering pump, «Section 11-02».

Possible Source(s):
§ Valve screen plugged.

Action(s) to Take:
§ Prior to rebuilding a pump, examine the valve screen for contamination, Replace all valves which have plugged or contaminated valve screens.

Possible Source(s):
§ Flex coupling rubbing against housing face.

Action(s) to Take:
§ Reposition flex coupling.

Possible Source(s):
§ Column misaligned or binding.

Action(s) to Take:
§ Align column assembly.


Regards,

Steve

<small>[ December 11, 2003, 04:00 PM: Message edited by: projectSHO89 ]</small>

 

[captinsho]

No appologies necessary. I just appreciate the assistance. Thanks!

 

[Rockledge]

When I had my '93 Sable I remember I read a little bit about VAPS in my '93-'94 Ford Factory Workshop Manual. I use the same manual now for my '94 SHO, obviously.

I was able to pull this out of there, might help you get an idea VAPS works:

Steering, Power--Variable Assist

The Variable Assist Power Steering (VAPS) system utilizes the existing steering components and by use of a power steering auxiliary actuator (3N803) and a power steering variable assist control and bracket (3F721) adds improved smoothness and handling characteristics.

The VAPS system consists of a microprocessor power steering variable assist control and bracket, a power rack-and-pinion steering gear (3504), a power steering auxiliary actuator, hose assemblies, and a high efficiency power steering pump (3A674) for:

- Taurus GL (High Series Only)

- Taurus LX

- Taurus SHO

- All Sables (Includes 3.0L and 3.8L)

NOTE: VAPS is not standard or available on Taurus GL lower series and Police.

The system uses a modified rotary valve in the steering gear with two independent hydraulic circuits called the primary and secondary circuits.

- During parking and low speed operation, the flow from the power steering pump is routed to the primary circuit by an electrically controlled power steering auxiliary actuator.

- As vehicle speed increases, the power steering auxiliary actuator gradually opens, diverting an increasing amount of fluid to the secondary circuit.

The power steering auxiliary actuator is a pressure-balanced variable orifice valve, controlled by a stepper motor-driven linear spool.

- The power steering variable assist control and bracket receives signals from a vehicle speed sensor (VSS) (9E731).

- Then it signals the stepper motor-driven spool to adjust the opening of the actuator valve.

The power steering variable assist control and bracket is programmed to perform a self-diagnostic check every 16 milliseconds.

- If a concern is detected, the power steering assist control and bracket microprocessor deactivates its output signals.

- The power steering variable assist control and bracket is programmed to perform a service diagnostic procedure when activated by the service technician.