Power steering hydraulic pipe

[dhb5610]

I have a leak on the power steering of my P5B saloon and its coming from the reducer that's fitted to the pipe that goes between the pump and the steering box. This pipe is less than 3 years old and now needs replacing again! I've been told that I don't need the reducer and that I can have a new pipe made without one thereby removing the possibility of it leaking again.

If I don't need to get a new pipe made with a reducer, why is it there in the first place and what purpose does it serve

[Phil Nottingham]

The reducer acts as a restrictor to prevent whining noise and vibration under certain conditions eg low speed turning and when the fluid is cold.

[dhb5610]

Thank you Phil

[lagain]

I fitted a new hose 2 years ago which has the reducer but at slower speeds turning the steering wheel is not as smooth as it used to be, but the last thing you want is for the hose to split and have fluid spraying every where !

[enigmas]

That's interesting about the reducer. Thinking about it's function like a reduction in the size of any orifice in a hydraulic circuit generally what occurs is an increase in the velocity of the fluid exiting at that point. Consider this in relation to a garden hose when a reducer or smaller nozzle is fitted. Also a reducer tends to even out fluctuations in pressure (introduces a fixed back pressure) making the output pump pressure more even and consistent AFAIK.

I can't see why a reducer would cause an inherent leaking issue. If so use an appropriate hydraulic sealant where it couples or attaches to the PSB.

[johnwp5bcoupe]

Apr 25, 2021 23:37:53 GMT enigmas said:

That's interesting about the reducer. Thinking about it's function like a reduction in the size of any orifice in a hydraulic circuit generally what occurs is an increase in the velocity of the fluid exiting at that point. Consider this in relation to a garden hose when a reducer or smaller nozzle is fitted. Also a reducer tends to even out fluctuations in pressure (introduces a fixed back pressure) making the output pump pressure more even and consistent AFAIK.

I can't see why a reducer would cause an inherent leaking issue. If so use an appropriate hydraulic sealant where it couples or attaches to the PSB.

I agree Vince it's probably a means to try and increase pressure to the box at low engine speeds ie parking? and as the pumps wear "and they do" the steering can/will get a bit heavier at low engine revs.

[dhb5610]

Hi Lagain

Thanks for you message mines been fitted since 2017 I got it from Wadhams  and since then the cars been off the road for over 12 months due to restoration work then hardly turned a wheel recently due to lock down. It's done less than a 1000 miles so I'm not best pleased in the meanwhile the price of a new one has gone up over £20 plus carriage over the last 4 years

[johnwp5bcoupe]

I had mine made several years ago by a Hydraulic Pipe company David and it's fine

[Ken Nelson]

Sometimes the worst thing you can do to a car is to have it sit stationless. I've often had silly things mysteriously fail after the car sits in my garage for a full winter. British goblins I guess.