Xantia power steering rack

Unread post by **KennyW** » 15 Feb 2009, 10:34

Hi Guys,

Just a quick question, What is the pressure that is applied to the power ram on Xantia's

Kenny

ACTIVE8 · Unread post by **ACTIVE8** » 15 Feb 2009, 17:35

Can you elaborate please!

Unread post by **KennyW** » 15 Feb 2009, 18:02

Active8,

I was wondering what the pressure was to move the hydraulic ram on the steering rack of my Xantia through the pinion valve.

I hope this makes it clearer.

Kenny

Unread post by **CitroJim** » 15 Feb 2009, 19:13

Not a huge amount I believe Kenny, nothing approaching main system pressure that's for sure.

The ram needs LHM in volume more than pressure.

Unread post by **myglaren** » 15 Feb 2009, 19:22

I wondered why they had devoted so many pump cylinders to it compared to the suspension and brakes, seemed contradictory to me, but then I nose nuthin'

addo · Unread post by **addo** » 15 Feb 2009, 20:23

That's a reflection of CJ's comment; it needs to move bulk fluid in a hurry.

My understanding is that pressure experiences transient spikes in a PAS setup. The connections all have to be capable of enduring these with a factor of safety on top (allowing for wear and other minor mishaps).

You could easlily get the service (neutral/steady state) pressures with a gauge plumbed into the line. But the spikes might be so quick that seeing the tip is a matter of extrapolation for most...

Regards, Adam.

bruno · Unread post by **bruno** » 16 Feb 2009, 00:52

I think the 6 pistons is to ensure more flow at a constant pressure for the steering. The suspension and brakes have the regulator to keep the pressure.

@addo, the usual pressure gauge is very slow to react (seconds, at least, since they work with internal springs), and the usual 6+2 pump is putting out something like 100 pressure spikes per second (6 per revolution) to the PAS system. I'd expect the gauge to give the average pressure anyway.

Pleiades · Unread post by **Pleiades** » 16 Feb 2009, 23:17

The ram should be getting full flow at a constant 150- from the pinion, this should drop to almost nothing when the steering is held at a full lock, then come back again as soon as the wheel is moved.

Note........

Been off for a while, you would not believe the troubles that a computor can cause...

Regards
Martin

Unread post by **CitroJim** » 17 Feb 2009, 06:20

Great to see you back Martin

Pleiades wrote: Been off for a while, you would not believe the troubles that a computor can cause...

I can! They keep me in a job

Martin, I need to have a chat with you about the availability of spare O rings for hydractive electrovalves. I'll give you a ring during the week...