Pump Clicking, every three seconds

[jamieb]

The pump is making a loud click every two/three seconds - very regular. It seems to stop when suspension is on its lowest setting and click less frequently when it is on high. Is this a problem - either something wrong with the pump or a sign of imminent system failure elsewhere?

The other thing bothering me at the moment is the red thingy for for measuring LHM level seems to sit right at the top of the dome whatever height the suspension is. It doesn't seem to be stuck as such because when I tap the dome with a hammer, it sinks down, then immediately bobs up again. Is there a way that LHM can be measured without this?

Would low LHM cause the clicking? (some hope)

A happy, freezing wet bank holiday to one and all.

JAmieb

[demag]

Regular fast clicking is normally associated with a failed or flat main accumulator sphere. This sphere acts as a backup fluid supply and safety reserve of pressure.

You need to get it replaced although I would say its not screaming desparate although others might disagree.

The indicator on top of the tank just shows lhm level in there. Take the plastic cap off the tank and look. High indicator means high level, no great shakes. Best to have too much than too little.

[Peter.N.]

Well, my own experience with Mk1 2.1 TDs is that a flat accumulator sphere can lead a fracture of the high pressure pipe at the point that it leaves the pump, in fact this happened to me twice. The Mk2s have a different pipe arrangement which doesn't seem to suffer the same fate. Maybe the petrol MK1s are different - but I just thought I would mention it.

Peter.N.

This post has been edited by Peter.N. on May 26, 2007 08:30 pm

[jamieb]

Sounds like I should see to it but it's good to know that complete disaster doesn't beckon. I'll top up the LHM - I wasn't sure if you could overfill it but it sounds like better safe than sorry.

Thanks chaps

Jamie.

[techmanagain]

Can't agree that the regular clicking is not a need for action - like now, if you are wise !
LHM level is checked with suspension on high. Then it should show orange cap between two level marks on gauge.

[robertxmb]

The LHM resevoir level is correct when the floating cap is level with the line on the plastic dome with suspension set to highest setting. At all lower settings, therefore, the cap is at the top of the dome. If overfilled, the resevoir might overflow when the system is depressurised for maintenance. Agree with others re accumulator sphere which maintains a resevoir of pressure if engine cuts out.

Bukko.

[jamieb]

I've been checking the LHM level with the suspension on high, ride and low, and in all cases, the red disk is right at the top of the dome. It's not jammed - when I tap it it bobs down and then bobs up again right to the top of the dome - again regardless of the suspension setting. I'm assuming therefore that the level is high.

Out of interest, is the accumulator sphere the same spec as the others, or is it different?

Also out of interest, where the **** is it?

[Zaphod]

Its the one on the front of the engine I belive!

Stewart

[Ciaran]

Have to agree that changing the sphere should be done sooner rather than later. Besides possible maintenance complications, the accumulator sphere is your only means of braking should the engine stop unexpectedly... I wouldn't want to leave it to chance and go careering into some thing/one!
I changed the one in my 2.0i today because it was ticking every 10ish seconds. For the sake of 20 quid, its not a big deal, better safe than sorry.

Regarding the fluid level, just be wary about putting in a wee bit too much LHM. I made that mistake once a few years ago, thinking the reservoir float was jammed (it was already too full), and topped it up even more.

Every morning for a few days I would come out and tear my hear out wondering why it had pissed huge amounts of fluid all over the drive. I later realised that there was far too much fluid in the system, and when the car was sinking overnight, it was all coming back to the reservoir and severely overflowing.

Peter, that’s a worrying point about the pipe fracturing at the pump. I presume this was due to the fact that it would be working almost constantly with a flat accumulator sphere?

Cheers

Ciarán


This post has been edited by Ciaran on May 26, 2007 11:21 pm

[DerekW]

It's probably due to the continuous pulses of pressure that occur when the pump is working. Pulsed loading and unloading of any structure will probably eventually cause fatigue failure.

Derek

[Peter.N.]

Hi Ciaran

Yes, its as Derek says, the accumulator sphere acts as a buffer against the sudden pressure increase when the pump, pumps, without that buffer the pipe can fracture. It usually goes at the weakest point, which is the flared end that fits in the pump.

Peter.N.

[Ciaran]

Thanks for that explanation, Derek & Peter.
Theres a hell of a reason to keep your accumulator sphere in good nick, (besides the little matter of not being able to stop, should the engine stall! )

Cheers

Ciarán

This post has been edited by Ciaran on May 27, 2007 03:47 pm

[jamieb]

I second that.

Jamie

[jamieb]

Just for the record, pump is now clicking every 15 seconds. A bit of aerobics seemed to help - could they have repressurised the accumulator sphere, I wonder? Anyway, this encouraged me to go on a two hour run to see XMexc - which I will write about in self help.

I shall change the sphere anyway. Am now wondering if there is an "ideal" interval between clicks - I mean, an interval that means the accumulator sphere is at the right pressure. I read somewhere that BX pumps should click every minute or so ...

[Ciaran]

Between 30-60 seconds at rest ideally.