Howling noise from Rack

[Tonybolony]

Hi All,
I recently replaced the main hydraulic pipe from the pump to the Steering Rack (the one with the steel 360deg loop, which had a pinhole in it).
Ever since, when 'loading' the steering wheel with engine running, there is a strange howling that can be heard inside with the windows closed, and it can be felt through the wheel.
The pipe that I fitted was made locally for me, a stainless braided unit which does not incorporate the loop. The only other difference is the solid block on the OE pipe where it fits into the wire support bracket under the water manifold (I don't suppose that is some form of pressure regulator/damper?)

Any suggestions??

[A80Avant]

Yes.
Replace it with a genuine one to avoid the noise. Apparently the genuine ones have antivibration material that prevent that noise from appearing

[Tonybolony]

Cheers A80,
I wasn't sure whether it was the pipe or the pump causing the noise- at least the genuine pipe is cheaper than a pump.

[A80Avant]

Trouble is that these are now become obsolete. Try and see if you can find one, but even used they should last.

I have had to get one as a spare as even audi tradition didn't have them.

[Error404]

You can get them remade, but they MUST reuse the ENTIRE length of the perforated plastic hose insert, right up into the hose ends as this is the vibration damper that stops this howling noise your are hearing (which is the PAS pump BTW).

[A80Avant]

You can get them remade, but they MUST reuse the ENTIRE length of the perforated plastic hose insert, right up into the hose ends as this is the vibration damper that stops this howling noise your are hearing (which is the PAS pump BTW).

I tried that as well. Didn't work.

On one previous attempt, the shop managed to retrieve the plastic insert but of course not the metal loop which they had already chopped.

The howling slightly mellowed but never went away. So maybe perhaps the loop is also required.

[Error404]

Yes you need to use the OEM hose ends and the complete insert.

[Tonybolony]

I'm glad I didn't bin the original hose then!
I'll get the pinhole welded up, and refit it. Meanwhile- is the noise just irritating, or is it likely to be detrimental to the hydraulic system??
Whilst on the subject- I have read other threads where members have mentioned the amount of Power Assistance as being too much, the Wheel feeling too light.
This certainly isn't the case with mine, and the brake pedal is also heavy. Any suggestions if this is down to the pump, the bomb- or just an individual characteristic?
(Both brakes and steering are acceptable, but certainly not OTT)
Oh, and Yes- the belt Is tight!!

[A80Avant]

Its difficult to say. If the thickness of the braided hose they made for you is not the correct size perhaps it could be straining the system. My suggestion is to put the old one back, see if everything goes back to normal and if not then you will know if the pump needs also rebuilding