Power steering funnies

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B-Hive
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Power steering funnies

Post by B-Hive »

Hey All

Thanks for all your continued help in keeping Margot on the road and improving every day.

Just whilst I'm here thought I'd field another strange symptom. This time with the power steering.

It seems that at lower speeds (particularly from takeoff) I get this sort of gentle pulsating sensation through the steering wheel, and occasionally on braking and turning I'll get a kind of juddering through the wheel.

My HP pump is soon to be swapped out as is very noisy and I suspect tired in the pressure department too, would this be the cause of these "strange sensations" through the wheel?. The whole rack is virtually brand new as was fitted prior to purchase so I 'm guessing the problem is not internal in the rack.

Thanks in advance
Current
85 BX GT Mk1..
86 BX TRS Mk1
87 BX TRi


Gone
85 BX TRS mk1 auto... SOLD
90 BX TRi..parts....cubed
citronut
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Post by citronut »

if the pump is noisy it may be sucking air, check the rubber supply hose from tank to pump for any cracking, the pump problem is almost certainly your steering fault, the first thing i would check is the fluid level, this must be done on the highest susp setting on level ground
regards malcolm
curent ride
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also own
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Post by mnde »

I was about to post about the very same thing!

I noticed the steering felt funny. Heavy at low speeds and sometimes a judder through the steering wheel, and the suspension felt all wallowy.

I later discovered I had a slow puncture in my nsr tyre and it was nearly flat... but I was able to pump it up and get home. That was a couple of weeks ago and I've been using the GSA ever since.

Yesterday I finally got round to changing the wheel. I noticed as I was moving the car from the sideroad into the parking bay that the steering was still heavy at low speeds and pulsed when I turned slowly to the right. I drove round an adjacent carpark and noticed a slight squeal at full lock. Aha!

So after changing the wheel, and finding the LHM level was correct, I tightened the hydraulic pump belt. Fixed, it seems! I hope so, because I was imagining all sorts of expensive possibilities...

Cheers,

Mark.
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DLM
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Post by DLM »

If the belt is tight and levels are OK, have you considered hydraflushing? Unless you are 100% sure the pump is on the way out, it's possibly a cheaper option (about £20 in the UK for a 5l container - GSF price when I last bought some). It's certainly worth comnsidering in the very long list of standard chacks and actions for BX steering problems.

A friend was having similar problems and the car was dismally slow to raise at the front. At present a hydraflushing treatment seems to have done the trick. Winters are definietly the worst time for this problem.
Back on two wheels and pedal power for the moment.
B-Hive
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Post by B-Hive »

Thanks guys!!

we're into summer here..yay!! let me see ...belt tight yep..levels ok...pump is noisy in a bearing sorta way. so i at least want to quieten it down..

tick time is quite low at about 20-25 seconds.. Front rises reasonably quickly and smoothly (although i suspect spheres need regassing). All that aside i figured that so long as the pump at least cycles off some of the time then presumably the accumulator has sufficient pressure..unless we're now talking regulator or accumulator troubles. BTW why does the system need a sphere on the accumulator and how do you know if its "flat"?

bye for now
Current
85 BX GT Mk1..
86 BX TRS Mk1
87 BX TRi


Gone
85 BX TRS mk1 auto... SOLD
90 BX TRi..parts....cubed
citronut
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Post by citronut »

if the car rises quite quickly its probably not the pump at fault, the pump will be noisy if its sucking air, and the noise is usualy the pistons inside the pump clatering, check the main sucktion feed pipe to the pump for cracks, as this will cause the pump to suck air
regards malcolm
curent ride
K reg BX 17TD TZD est
also own
K reg D special

no longer have
H reg CX saffari 2.5 TRI (now gone to Malaysia)
R reg xantia 1.9TD est (gone to meet its maker)
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Post by roscoe »

The accumulator sphere is a source of reserve pressure for the system - it allows your brakes to work if your pump belt breaks while driving - gives you enough reserve pressure to be able to both keep the car off the ground and safely stop it. Imagine what would happen without a pressure reserve source if you broke a hydraulic belt - instantly no brakes, suspension would drop and you'd be in big trouble :cry:
For the steering shuddering when starting off or turning, one other suggestion would be to check your driveshaft CV joints - I had a similar problem on another front wheel drive car (not a Cit) that did that and never gave the other tell-tale sign of CV failure - clicking on hard turns at slow speeds. It got progressively worse and after checking and suspecting everything else, finally pulled a driveshaft out and the inner joint was so loose it was basically rotating a partial turn before 'locking' and turning the outer part of the shaft. This was then transmitted through the steering and caused the juddering and strange feeling when turning and starting off.
cheers,
Roscoe
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Post by AndersDK »

na - na -

The infameous FDV is fitted to the BX hydraulics - equipped with power steering - exactly to prioritise the power steering. This means that the power steering always gets first priority with any available hydraulic pressure from the pump.

Now remember here that the power steering circuit is connected to the pump - BEFORE - the pressure regulator and accumulator sphere feed - exactly by the FDV.
In turn this means that any flat acc sphere does not influence the power steering - but will of course give the wellknown symptoms from the brakes and suspension part of the system.

A power steering fitted BX have the following pressure feed priority :
Pump -> FDV -> powersteering -> FDV -> PR -> accumulator -> brakes -> priority (safety) valve -> suspension.

The only exception is when the FDV is at fault. In this case the FDV internal sliding valves seems to be random in their decision of who is getting priority of pressure. This is caused by partially sticking valve sliders inside the FDV.
Wellknown by sudden lack of steering help during drive - and/or the hydraulic warning and STOP lamp coming on at random during drive.
Feels like the steering wheel suddenly freezes.

The point is, that a flat acc sphere wont affect the power steering.
But a weak pump will at low revs kick through with every piston movement to the steering wheel. Therefore the rough feeling on the steering.
C U / Anders - '90red16riBreak - '91GrisDolment16meteor - Project'88red19trsBreak
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Post by citronut »

Anders the route of flow is as you say appart from the supply for the brakes runs through the safty valve
regards malcolm
curent ride
K reg BX 17TD TZD est
also own
K reg D special

no longer have
H reg CX saffari 2.5 TRI (now gone to Malaysia)
R reg xantia 1.9TD est (gone to meet its maker)
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Post by AndersDK »

citronut wrote:Anders the route of flow is as you say appart from the supply for the brakes runs through the safty valve
regards malcolm
Nope - Malcolm 8)

The supply runs TO the brakes AND the safety valve.
The safety valve is nothing but a distributor in the case of feeding pressure to the brakes. Thats exactly the main idea on the safety valve : ALWAYS feeding the brakes, but shutting off suspension supply once the pressure is down below 100bar.
The pipe port that takes the PR feed pipe is directly connected to the brakes supply pipe port ...
Take a look on safety valve from your stock !

A further note to my previous explanation :
There is a very good reason why Citroen designed in the FDV in the hydraulics circuit.
Imagine there were no FDV in the circuit. You are turning, and suddenly the PR clicks in to charge the accumulator ... :evil:
C U / Anders - '90red16riBreak - '91GrisDolment16meteor - Project'88red19trsBreak
dead cars : '89white 16RS - '89antrasitTRDturboEst - '90white19triBreak
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Post by citronut »

that is exactly what i said Anders HAPPY XMASS
regards malcolm
curent ride
K reg BX 17TD TZD est
also own
K reg D special

no longer have
H reg CX saffari 2.5 TRI (now gone to Malaysia)
R reg xantia 1.9TD est (gone to meet its maker)
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AndersDK
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Post by AndersDK »

citronut wrote:that is exactly what i said Anders HAPPY XMASS
regards malcolm
and a happy new year to you Malcolm beers
C U / Anders - '90red16riBreak - '91GrisDolment16meteor - Project'88red19trsBreak
dead cars : '89white 16RS - '89antrasitTRDturboEst - '90white19triBreak
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