mk 5 transit lack of power steering

[the snooper]

as the title the power steering is badly lacking so I have
1, replaced all the seals, it had no effect whatsoever, no better no worse
2, changed the pump again no change
3, changed the spool valve no change

the wheels pivot freely when the track rods are removed, there is no fluid passing the ram seal I have checked and its driving me mad never mind its driver that aching arms

any ideas ?

 

[Woody.v8]

If the pumps OK it must be the rack

 

[the snooper]

If the pumps OK it must be the rack

that's what I'm thinking but ive swapped everything

 

[Woody.v8]

Dose the rack turn freely ?

 

[the snooper]

Dose the rack turn freely ?

perfectly ive put a full seal kit in it and tried another spool valve

 

[Woody.v8]

Just cut it up and sell me the back axle.....
Kidding,
well if the pumps making pressure its got to be the rack ?

 

[the snooper]

Just cut it up and sell me the back axle.....
Kidding,
well if the pumps making pressure its got to be the rack ?

its driving me mad not being able to correct it, I'm wondering if the spool valve torsion bar can work harden with use and become less flexible and in turn hardly any pressure getting to the ram

 

[Woody.v8]

its driving me mad not being able to correct it, I'm wondering if the spool valve torsion bar can work harden with use and become less flexible and in turn hardly any pressure getting to the ram

Possibly, I'm not a expert with these racks but your theory sounds good?

 

[the snooper]

Possibly, I'm not a expert with these racks but your theory sounds good?

the thing is if you turn the steering hard over until its stops then pull on the steering wheel you can feel the torsion bar twist and the pump starts to squeal but try turning the wheel whilst stood still and its stupidly heavy and the pump doesn't squeal so I'm wondering if the valve isn't operating

 

[Woody.v8]

the thing is if you turn the steering hard over until its stops then pull on the steering wheel you can feel the torsion bar twist and the pump starts to squeal but try turning the wheel whilst stood still and its stupidly heavy and the pump doesn't squeal so I'm wondering if the valve isn't operating

Sounds that way

 

[the snooper]

Sounds that way

its one of those things that drives you mad as you cant see whats going on and the fact all the seals are new and not leaking makes it even harder to think of a reason for it not working

 

[doubleboost]

You need to put a pressure gauge in the main pressure line

 

[the snooper]

You need to put a pressure gauge in the main pressure line

I had thought of that but don't have one unfortunately, although I do have a hydraulics one man band as a neighbour

 

[normspanners]

steering column u/j seized ??

 

[the snooper]

steering column u/j seized ??

no everything moves freely

 

[octo0072000]

i will go with DBs suggestion pressure gauge to check and lack of pressure from pump

 

[the snooper]

i will go with DBs suggestion pressure gauge to check and lack of pressure from pump

pump has pressure as you can hear the relief valve operate on full lock

 

[octo0072000]

pump has pressure as you can hear the relief valve operate on full lock

relief valve could be operating at wrong pressure that's the cheapest option when you changed it was it used or new

 

[rikrobson]

Have you tried putting fluid in?

 

[octo0072000]

could be power steering high pressure pipe collapsing internally under pressure not allowing full pressure to the rack