Any power steering wizards on here?
Discussion
Might be a bit of a ramble this but I will try to be structured!
Mk4 Mondeo, 2009 with 98K on when I bought it.
Had a squealing power steering pump but there was a new one in the boot, seller fitted this for me when I bought the car.
I noticed after a while that the car had very light steering turning right. So much so the car would wander to the right if the hand was off the wheel even on fairly level roads. Alignment carried out still did it.
Occasionally I would get aeration in the power steering fluid which would make it noisy again. I flushed the fluid this seemed to help this.
Had the car lifted front wheels up while running and putting pressure from the wheels revealed that indeed there was less resistance pulling the wheel right as to left, diagnosed with a bum seal in the rack.
New refurb rack fitted and 4 wheel tracking. Car felt horrible and steering vague, doesn't wander to the right but is still lighter to steer to the right.
For giggles I changed both top mounts and arms and another alignment. Car drives better now but is still lighter to turn to the right.
I'm pretty sure even at stationary there is more resistance in the wheel to the right but it really shows up when at a bit of speed.
Am not sure where to go from here but it is doing my head in.
I suspect that as it's seems to be there from stationary its either the rack or the no name power steering pump.
Could a cheap pump give the problem?
Any pointers would be great.
Mk4 Mondeo, 2009 with 98K on when I bought it.
Had a squealing power steering pump but there was a new one in the boot, seller fitted this for me when I bought the car.
I noticed after a while that the car had very light steering turning right. So much so the car would wander to the right if the hand was off the wheel even on fairly level roads. Alignment carried out still did it.
Occasionally I would get aeration in the power steering fluid which would make it noisy again. I flushed the fluid this seemed to help this.
Had the car lifted front wheels up while running and putting pressure from the wheels revealed that indeed there was less resistance pulling the wheel right as to left, diagnosed with a bum seal in the rack.
New refurb rack fitted and 4 wheel tracking. Car felt horrible and steering vague, doesn't wander to the right but is still lighter to steer to the right.
For giggles I changed both top mounts and arms and another alignment. Car drives better now but is still lighter to turn to the right.
I'm pretty sure even at stationary there is more resistance in the wheel to the right but it really shows up when at a bit of speed.
Am not sure where to go from here but it is doing my head in.
I suspect that as it's seems to be there from stationary its either the rack or the no name power steering pump.
Could a cheap pump give the problem?
Any pointers would be great.
Pump is probably over flowing, the original pump will be specified for a specific flow at a specific rpm. This is probably giving more.
The pressure and consequently the level of assist is determined by a valve in the rack, but that valve will be configured for the pump of specific flow, more flow = more pressure. Especially if it's exceeding the tank flow capacity of the valve.
The pressure and consequently the level of assist is determined by a valve in the rack, but that valve will be configured for the pump of specific flow, more flow = more pressure. Especially if it's exceeding the tank flow capacity of the valve.
Is the rack bent?
Cars that take knocks to the front wheels (like kerb strikes) can easily bend the rack bar (the toothed bit in the rack that is driven back and forth by the pinion) and once that's bent, you get all sorts of horrible stiction feeling as it passes through the bearings and pinion housing etc
If it feels the same with the engine off (ie the same amount of friction turning left or right) then the rack is straight and the spool valve may be worn or have debris trapped in it.
In all cases, you'd be looking at swapping out the entire rack.
Cars that take knocks to the front wheels (like kerb strikes) can easily bend the rack bar (the toothed bit in the rack that is driven back and forth by the pinion) and once that's bent, you get all sorts of horrible stiction feeling as it passes through the bearings and pinion housing etc
If it feels the same with the engine off (ie the same amount of friction turning left or right) then the rack is straight and the spool valve may be worn or have debris trapped in it.
In all cases, you'd be looking at swapping out the entire rack.
bungz said:
The rack is a refurb from western power steering. A ok company from all reviews I have read.
Its just odd its light in the same direction the old rack was.
Ask the people who supplied it whether they can shed any light on the problem. The suppliers might well recognise the symptoms and point to a problem in the rack or the way it is installed.Its just odd its light in the same direction the old rack was.
Slim odds but it could be worth checking for stiffness in the steering column/shaft U/J before spending any more money.
Partial seizing in a joint can give weird steering, you mght not need to remove the shaft to check.
If you find a stiff spot then give the steering wheel another complete turn and see if its still the same.
Partial seizing in a joint can give weird steering, you mght not need to remove the shaft to check.
If you find a stiff spot then give the steering wheel another complete turn and see if its still the same.
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