BX Hydraulic Pump squealing

[foz]

Greetings,
I've had a Citroen BX 16RS for a few years now (E reg). It's a great motor that just keeps going, but recently developed a squeal. The high pressure pump for the suspension was stopping, seemed to be sticking. The drivebelt then caused the squeal as it tried to turn the pump.
I've replaced the high pressure pump with one from a scrapyard, got the pressure back ok with the 'stop' light off, but it still sticks and squeals. I'm wondering now if it's the pressure regulator that I should change (too much pressure stopping the pump?) and whether I need to also change the globe attached to the regulator? Is it one unit, is there anything I can do to service it?
The suspension pumps up to full height (with the squeal) and the pressure releases ok when the internal control level is moved. Am I right in assuming that this means the security valve is working ok?
Any thoughts on this greatly apprieciated, cheers ... Ian

[AndersDK]

Replace the drivebelt for the pump, as the long time squeeling has damaged it.
Then ensure the belt is <font color="red"><i>incredible tight</i></font id="red"> [}:)]
- nothing like an alternator belt [8)]

[foz]

Thanks for reply, did try that before replacing the pump. It stopped the squeak for a week or two. When the pressure release screw is loosened the pump turns ok, but it sticks when this is tightened.
<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote"><i>Originally posted by AndersDK</i>

Replace the drivebelt for the pump, as the long time squeeling has damaged it.
Then ensure the belt is <font color="red"><i>incredible tight</i></font id="red"> [}:)]
- nothing like an alternator belt [8)]
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">

[jeremy]

Have you got power steering? Is it working normally or has it become light?
The security valve simply opens when sufficient pressure is available and extinguishes the light, allowing pressurised fluid into the suspension and rear brakes at the same time.
The pressure regulator has a high and low pressure valve to control the pressure between defined limits and makes the characteristic ticking noise when working correctly. Does the pump noise change while the car is rising? In theory the high pressure valve could fail and might stall the pump but it would not do this while the suspension was rising as this would drop the pressure. The 'globe'attached to the regulator is the accumulator sphere and can fail causing strange symptoms but not generally yours. To test it, get the car to normal height, turn off the engine and go and sit in the boot. The car should then drop but after about 30 seconds rise to its original height. If everything else is working correctly and the car doesn't rise then the accumulator has failed.
The FDV which splits the supply for the power steering contains a pressure relief valve under the hexagonal plug. This will control the ultimate system pressure but is unlikely to fail producing extra pressure as its a simple ball valve with a follower and spring.
I suppose your drive belt is a multigrooved belt on the front of the engine. Are the pulleys in good condition or has one (for example the crankshaft pulley) worn in its grooves? Is the crankshaft pulley still firmly attached?
Jeremy

[AndersDK]

foz -
your BX 16RS has no servosteering, and then the dead simple basic hydraulic system.
It's imperative the drivebelt is <font color="red"><i>incredible</i></font id="red"> tight, and rides on the sides of the V-grooves, otherwise it <font color="red"><i>will</i></font id="red"> slip and squeel.
Funny - but once the belt is good and correctly tightened, it will last very long.
When the pressure release screw is opened, the LHM simply idles from reservoir via the pump to the regulator and back to reservoir.
The pump then never sees any resistance, and is easy to turn.
If the pressure regulator does not release at the max pressure of 170bar, then the pump is loaded hard and would cause the engine to stall at normal idle.
The drivebelt <font color="red"><i>should</i></font id="red"> in fact not give up, and start slipping/squeeling.
It is much the same situation as when you have a very hard load on the alternator at engine idle : the engine may in fact stall.
Are you dead sure the drivebelt is fresh and correctly adjusted [?]
You might have the V-grooves filled up with compacted dirt, which then prevents the belt to tension on the sides of the V-grooves.
As you can read, I keep drawing your attention to any belt problems [;)]
- because it is the most common problem at all with the symptom given.

[jeremy]

Remember this thread Anders?
viewtopic.php?t=1582
jeremy

[AndersDK]

No -
- but you did J [;)]

[foz]

OK, ok, I got the message! I looped a bit of rope over the pulley wheel from under the car then put my weight on it to really tighten the belt before tightening the bolts.
The sqeak has now stopped and the suspension feels much firmer to drive than it has done for a long time. It corners now like it did when I first bought it, which is great.
Many thanks,
Cheers
Ian

[Paintingbox]

I know this is a really old thread but my 89 BX 17RD is doing this exact same thing. I wonder if anyone has any further thoughts as the belt is new and so is the accumulator sphere. Is it really just a question of belt tightness. It is not random as to when it happens, its regular approx every 62 seconds

Thanks

[xantia_v6]

It is probably due to insufficient belt tension, but check the pulley for wear, make sure that the belt is not sitting at the bottom of the V.

[white exec]

Try squirting some water (not WD40) at the belt, and see whether that temporarily kills the squeal.
If it does, it confirms that it's belt squeal your getting, rather than pump problem.

The vee-belt on the BX needs to be fairly tight to prevent slippage; you should not have very much in the way of "twistable" belt between the pulleys. It is possible to use a brief dose of V-belt conditioner; this is a mild solvent which also leaves the belt slightly tacky, and increases its grip on what will be well-polished pulleys. (Not for use on grooved, flat belts.)

The squeak you hear at 62sec intervals is the pump cutting in periodically to top up system pressure. 60+sec is good . . . less than 10sec usually suggests that the Accumulator sphere is down on gas.

[Paintingbox]

Thanks Chris for the water tip, I'll try that tomorrow, just about to get on the ferry to Cherbourg now!