Power steering fluid frothy

Power steering fluid frothing

300 tdi in a series with power steering

Always had problems with frothing fluid / poor power assistance ,finally got round to changing steering box as it leaked but it didn't help

Fitted a new pump today and it's still the same

No visible leaks but I assume there air getting into the system

Anyone else had this? Is it most likely to be on the suction side of the pump ?

Low pressure to the pump, high to the box, low back to the bottle.

It could be sucking air in to the pump.
I could be air in the steering box.
The boxes are nominaly self bleeding (go from lock to lock, slowly, with the engine running a bit faster than tickover).
There is a bleed nipple on top of the box, I had one that I needed to bleed the air out but most I have dove have done it them selves.

Cavitation --- the pump cant get enough fluid. Supply pipe not a big enough diameter, blocked pipe, restricted reservoir outlet.

Change the hoses

Rock Basher said:

Change the hoses

Click to expand...

For what ?
New hoses ??
I won't be original then though will it ???

Which hoses should he change, all three or just the soft one ?

Should he go for LR, OEM, Britpart or another make ?
What are the part numbers ?

Why should he change the hoses ?
What will that achieve/show ?

Saying "change the hoses" is about as much use as an ashtray on a motorbike.

miktdish said:

For what ?
New hoses ??
I won't be original then though will it ???

Which hoses should he change, all three or just the soft one ?

Should he go for LR, OEM, Britpart or another make ?
What are the part numbers ?

Why should he change the hoses ?
What will that achieve/show ?

Saying "change the hoses" is about as much use as an ashtray on a motorbike.

Click to expand...

Did you have fun typing that?

Rock Basher said:

Did you have fun typing that?

Click to expand...

@ironie much

Thanks that would explain it ,she has a 3 bolt steering box mated to a 300 tdi pump so hose from pump to box is 2 grafted together

Would it only be the supply hose from the resivour or would a restriction anywhere cause cavitation ?

miktdish said:

Low pressure to the pump, high to the box, low back to the bottle.

It could be sucking air in to the pump.
I could be air in the steering box.
The boxes are nominaly self bleeding (go from lock to lock, slowly, with the engine running a bit faster than tickover).
There is a bleed nipple on top of the box, I had one that I needed to bleed the air out but most I have dove have done it them selves.

Click to expand...

I've bled it many times but only works for a short time (been ongoing for years)

chrisstdt said:

I've bled it many times but only works for a short time (been ongoing for years)

Click to expand...

If it's leaking fluid air is getting in.

Rock Basher said:

If it's leaking fluid air is getting in.

Click to expand...

No leaks now box is changed which is what made me think it may be drawing on the suction side

Fair enough

chrisstdt said:

Thanks that would explain it ,she has a 3 bolt steering box mated to a 300 tdi pump so hose from pump to box is 2 grafted together

Would it only be the supply hose from the resivour or would a restriction anywhere cause cavitation ?

Click to expand...

Only the supply hose/pipe. If you can change the pipe....a decent bit of oil resistant hose....as big as the inlet of the pump/outlet of res then it'll be perfect

EeEk said:

Only the supply hose/pipe. If you can change the pipe....a decent bit of oil resistant hose....as big as the inlet of the pump/outlet of res then it'll be perfect

Click to expand...

Thanks il give that a go tomorrow

200 90 has a rubber hose that is shaped 90 degrees before pump, mine delaminated and collapsed inside.

Changed the hose from resivour to pump and its just the same
Frothing up to the point where it pushes foamy fluid out the breather of the resivour

Power steering works butbif I go for a run it will stop working

I don't know what fluid reservoir you're using but if it's the round plastic ZF type it has a filter gauze inside it. If this gets blocked it can lead to your pump sucking air as it can't receive a supply of clean fluid.

Rangieman123 said:

I don't know what fluid reservoir you're using but if it's the round plastic ZF type it has a filter gauze inside it. If this gets blocked it can lead to your pump sucking air as it can't receive a supply of clean fluid.

Click to expand...

Hi it is the round zf type

Thanks il give that a try