Help! No Power Steering or Brakes after vacuum pump swap

[IBMobile]

37 minutes ago, RayNAz said:

In general, does it come back a bit at a time or all at once?

There should be power steering and brakes immediately all though it may be jerky and noise from the system due to the entrained air and slowly go away in a day or two.  There is flow so the pump is delivering fluid but is there pressure?   I think you have "3.  That pressure regulator in the pump has gotten stuck open and even though there is flow the pressure is too low to do the job."  If the high-pressure line/hose was blocked there would be very little flow and the pump would be making a noise as if the steering wheel had been turned to full left or right with no let up.   You may want to remove the pressure relief valve and inspect it.

 

[Tractorman]

On 12/15/2024 at 8:36 PM, Tractorman said:

Place the vacuum pump unit in a vise.  Make a suitable tool that can be operated with a wrench to engage into the jaw coupling hub.  Have helper hold the gear from rotating with the use of a strap wrench.  Using the newly made tool and the wrench, try to rotate the coupler in the opposite direction of normal rotation to see if it slips.  Use your best judgement on how much force to apply.  If it slips, you have your answer.

 

@RayNAz, did you skip this step while you had the unit on the bench?

 

- John

[RayNAz]

22 minutes ago, IBMobile said:

There should be power steering and brakes immediately all though it may be jerky and noise from the system due to the entrained air and slowly go away in a day or two.  There is flow so the pump is delivering fluid but is there pressure?   I think you have "3.  That pressure regulator in the pump has gotten stuck open and even though there is flow the pressure is too low to do the job."  If the high-pressure line/hose was blocked there would be very little flow and the pump would be making a noise as if the steering wheel had been turned to full left or right with no let up.   You may want to remove the pressure relief valve and inspect it.

 

Thanks !  The fluid was pretty old when I started this whole mess (since flushed) so it's certainly possible that the screen got clogged when I was maneuvering the pump out of the truck or the valve is otherwise gunked up.  I'll pull the fitting and valve etc and have a look.

 

[RayNAz]

1 hour ago, Tractorman said:

 

@RayNAz, did you skip this step while you had the unit on the bench?

 

- John

 

Completely forgot but I'll check when I have it out to check the pressure relief valve.  I did take measurements as you suggested and that, at least looked acceptable.

[Tractorman]

You can remove the flow control / pressure relief valve cartridge without removing the power steering pump.

 

- John

[RayNAz]

Anyone know what size wrench/socket is needed for that fitting?  It looks like about 26mm or 1 inch but I thought I'd ask.

[IBMobile]

I can't remember exactly but it's either a 15/16 or 1".