Thread: Defender Power Steering Problem

if its been emptied it may be purging.

if youve over filled it it may just be the oil heating up and overflowing.

if you havent over filled it that much and its not always coming out only when the relief valve kicks on the ps pump (thats not how it actually works but the effect is about the same) then the back pressure from the pump can make the oil spurt.

syringe the oil back to the right level and go again.

Thx for the reply but not quite sure what I need to do. There never used to be a problem and it's not overfilled.

What does purging refer to?

It seems to get worse as the fluid heats up.

Is the back pressure incorrect? How do I sort this out? The fluid lasts a day.

What is the relief valve?

if youve let the level get low (say it has some other leak) when air gets into the pump and pressurised into the steering box it hangs around there when the air gets pushed out of the box its in the Low pressure line and on the way back to the tank, once the air is in the low pressure line it expands pushing the oil in the line along faster and this can make the oil spit out of the tank.

Thats purging.

the relief valve is in the pump, its there to stop the whole thing from exploding when the pump is trying to push oil when the oil doesnt want to move dont panic about it these only ever fail one of 2 ways, they either stick open and you loose power assist or they stick closed and you blow hydraulic bits into smaller less functional hydraulic bits.

The back pressure thing is like water hammer when you quickly snap a tap shut in a perfect world its never a problem, but as the world isnt perfect it sometimes shows up. As its not something thats ment to be there in a way bad enough to cause problems theres no way to adjust it. IME its only ever a problem if the oil level is too high in the tank.


take the cap off and with safety glasses (or a face shield on) have someone start the engine and watch what the oil does. That'll give you more clues as to whats going on. Let us know what the clues are, we'll put on our cluedo hats and see if we cant work out weather or not it was MR cavitation in the steering pump with the atmosphere thats causing your oil to bleed out.

Ok, I topped up the reservoir (It was completely empty) and turned the steering 10 times to full lock on each side and nothing leaked. I then waited for 20 minutes of idling to heat up the engine and fluid and still nothing.

I managed to identify a very small leak where one of the rubber hoses is clamped on to an unidentfied engine part. There are two hoses coming from the reservoir, one starts of as a rubber hose and then becomes a steel tuve that goes to the steering pump. The other one (the leaking one) is rubber all the way through and also comes from the reservoir but seems not to be going to the steering pump. Does anyone have an idea what this pipe does.

Lastly, ho wdo I bleed all teh air out of the steering system?

Thx

the hose that doesnt goto the pump is the return from the steering box.

what I suspect is happening is this.

its leaking, when it gets low enough it starts to suck air into the pump. when this returns from the steering box it bubbles and spits and then goes all over the shop.

it can also be venturi-ing air in through the leak which will have much the same effect.


once you replace that bit of hose bleeding is just a case of filling the reservoir to the correct level starting the engine and then turning the wheel lock to lock several times while someone else adds oil to the reservoir.

you dont need to idle for 20 minutes to warm up the powersteering oil. a couple of minutes to bleed it and make sure that its somewhere between hot and cold levels.