Mk4 Ls400 Steering Noise

[Parrot of Doom]

There's a bit of a groan lately from my power steering, when significant demands are being made of it (turning while stationary, etc). Fluid level seems ok (although discoloured). I can feel it slightly, through the steering wheel, and perhaps I'm imagining things but there may be a little bit more resistance.

I'm going to siphon out the old fluid and put some new oil in there but I doubt that'll fix it. What's likely to be the problem, the pump? The car tracks just fine. If it is the pump, well, the car will need a new cambelt in the next 12 months so I'll probably just have both replaced at the same time.

[sir john]

Sounds like the pump to me. They make a groaning/yowling noise when things are not right. Mine does it when the fluid level drops.

If the fluid is dicoloured, maybe one of the seals is starting to disintegrate. Could be in the PAS pump or the rake.

[Parrot of Doom]

Well it got really loud all of a sudden, so I checked the fluid level again and it was pretty low. Topped it up and it's gone quiet again, except when turning the wheel in reverse - there's a slight groan there.

Something to be monitored, I think.

[sir john]

I’d say you have a leak where the reservoir and the PAS pump
meet (an easy fit) or a leak at the rack (fecking nightmare to fix).

Feel round the bottom of the PAS pump for fluid. If it’s wet you have a leak there. A 5p O ring will fix it I’m told, but I
played safe and bought a repair kit from Lexus for about £12 and I still have
95% of the kit left. If it is the seal
between reservoir and pump, you need to get it fixed PDQ otherwise it will
wreck your alternator. That’s another £180.

[cruisermark]

I’d say you have a leak where the reservoir and the PAS pump

meet (an easy fit) or a leak at the rack (fecking nightmare to fix).

Feel round the bottom of the PAS pump for fluid. If it’s wet you have a leak there. A 5p O ring will fix it I’m told, but I

played safe and bought a repair kit from Lexus for about £12 and I still have

95% of the kit left. If it is the seal

between reservoir and pump, you need to get it fixed PDQ otherwise it will

wreck your alternator. That’s another £180.

i though that problem was only on the earlier ls400s - hes got a Mark 4?

[ManicMark]

Well it got really loud all of a sudden, so I checked the fluid level again and it was pretty low. Topped it up and it's gone quiet again, except when turning the wheel in reverse - there's a slight groan there.

Something to be monitored, I think.

Check the pipe that runs in front of the radiator down the bottom as these rust & leak. can be fixed with a piece of copper tube .

[Parrot of Doom]

That's a very good point - mine looks like the surface of Mars. I shall investigate and replace. I don't suppose you know the diameter, is it 8 or 10mm by chance? I have a big roll up in the loft.

[ManicMark]

That's a very good point - mine looks like the surface of Mars. I shall investigate and replace. I don't suppose you know the diameter, is it 8 or 10mm by chance? I have a big roll up in the loft.

I can't remember I will measure it later & get back to you.

[ManicMark]

That's a very good point - mine looks like the surface of Mars. I shall investigate and replace. I don't suppose you know the diameter, is it 8 or 10mm by chance? I have a big roll up in the loft.

I can't remember I will measure it later & get back to you.

Looks like 10mm didn't have a measure on me.