Hi guys I'm a new boy to the forum, so excuse any improprieties.
I have a BX problem which has me flummoxed. Recently my trusty steed, a BX TGD Turbo of fourteen years, developed that regular tssst-tssst noise with a frequency of around 10 seconds. Having seen this previously some years ago, I replaced the accumulator sphere, ordered of course through GSF. The performance of the car is fine- good ride, and brakes O.K. However the noise persists at that same 10 s frequency despite the new sphere. I also have noticed that when the engine is switched off there is a hissing sound from the front end (a bit like a deflating sound)for a few seconds that I have not usually heard. It is possible that this sound is continuous with the running of the engine, but may not be able to hear it over the engine noise.
Other observations and facts are:
1. the self-levelling response upon loading the back end after the engine is off, is a bit weak
2. a year ago the hydraulic pump was replaced. After hydraflush, I had to replace the LHM with Comma LHM plus (which appears by visual behaviour to be lower viscosity) as I couln't find a local supplier of Total LHM.
Anyone have any bright ideas? As the car is working alright I may be fussing unnecessarily, but if this is a symptom of a problem its best to get it before it gets me.
Frequent tssst noise and hiss
Moderator: RichardW
Hi Barny,
- first off : The LHM hydraulic fluid is made to Citroen spec, no matter maker or brand. Does not have to be Total brand. No problem to use any brand LHM fluid you can get. It's like engine oils available in a huge range of good brands.
The self levelling load regulation is slow working, as the HC has a build-in restrictor, to avoid the level setting fluctuate on normal suspension movements. Commonly it would take approx 30seconds or more to regain correct level.
If this seems only to happen when you "help" the car by jerking it, then you most likely have a problem with dry & rusty linkages. may even be time to have the linkage adjusted, as the manual height setting interferes with the automatic load levelling, to change the height.
It's not easy to reckon what's going on at the PR in a diesel, as the diesel clatter hides the usual wellknown tick/hiss sounds.
Instead try unplug each of the SMALL rubber return hoses at reservoir, and look for any flow of LHM (leading the hose into a jar).
Ideally there should be no flow at all with engine idle & normal height.
A few drops now & then, or slow dripping, are perfect indications.
Fast dripping is well acceptable in a car your age (errr... the car that is [:I]).
But if you have a constant flow, then the components related to that return hose have too much drainage leak.
Visually judging the flow is a pointer to severity of the problem :
a) If the flow is just barely trying to revert to fast dripping, it's nothing dangerous, but a telltale you're facing maintenance/repair work soon.
b) If the flow is constant and solid, you must prepare for repair work first off.
c) If the flow appears to eject with (even high) pressure, you need to repair ASAP, and the car MUST be considered dangerous to drive, as riscs are the return hose may burst, thus leaving you with no LHM fluid within few seconds. This compares to a burst brake line in a normal sprung car.
NOTE : On BX'es the small 90deg elbow rubber on reservoir contains a ballbearing valve. Be careful removing the elbow, as the bb most likely will find a new obscure location down your driveway. That is - if the previous woner (or garage !) not already have lost it for you [8D]
- first off : The LHM hydraulic fluid is made to Citroen spec, no matter maker or brand. Does not have to be Total brand. No problem to use any brand LHM fluid you can get. It's like engine oils available in a huge range of good brands.
The self levelling load regulation is slow working, as the HC has a build-in restrictor, to avoid the level setting fluctuate on normal suspension movements. Commonly it would take approx 30seconds or more to regain correct level.
If this seems only to happen when you "help" the car by jerking it, then you most likely have a problem with dry & rusty linkages. may even be time to have the linkage adjusted, as the manual height setting interferes with the automatic load levelling, to change the height.
It's not easy to reckon what's going on at the PR in a diesel, as the diesel clatter hides the usual wellknown tick/hiss sounds.
Instead try unplug each of the SMALL rubber return hoses at reservoir, and look for any flow of LHM (leading the hose into a jar).
Ideally there should be no flow at all with engine idle & normal height.
A few drops now & then, or slow dripping, are perfect indications.
Fast dripping is well acceptable in a car your age (errr... the car that is [:I]).
But if you have a constant flow, then the components related to that return hose have too much drainage leak.
Visually judging the flow is a pointer to severity of the problem :
a) If the flow is just barely trying to revert to fast dripping, it's nothing dangerous, but a telltale you're facing maintenance/repair work soon.
b) If the flow is constant and solid, you must prepare for repair work first off.
c) If the flow appears to eject with (even high) pressure, you need to repair ASAP, and the car MUST be considered dangerous to drive, as riscs are the return hose may burst, thus leaving you with no LHM fluid within few seconds. This compares to a burst brake line in a normal sprung car.
NOTE : On BX'es the small 90deg elbow rubber on reservoir contains a ballbearing valve. Be careful removing the elbow, as the bb most likely will find a new obscure location down your driveway. That is - if the previous woner (or garage !) not already have lost it for you [8D]
Sounds to me like the non-return valve in the regulator needs re-seating. The good news is that you can do it in situ and it costs nothing.
Trmove the accumulator sphere and then the bolt that is visible. When you take the plate off the ball may fal out so be careful. If it does not it will stick to a blob of brease on the end of a rod.
To re-seat simply give it a smart tap using a BRASS or similar punch. just one smart blow should be sufficient then re-assemble and see what happens. I have done this with 2 regulators and the difference is staggering.
For the first one I did not have a suitable bit of brass and fastened a coper MIG welder nozzle (wrecked) to a punch using an old Citroen pipe seal! The great thing is not to use a steel rod as you will put a flat on the ball and it won't seal.
Incidentally my regulator now cycles at over 1 minute.
jeremy
Trmove the accumulator sphere and then the bolt that is visible. When you take the plate off the ball may fal out so be careful. If it does not it will stick to a blob of brease on the end of a rod.
To re-seat simply give it a smart tap using a BRASS or similar punch. just one smart blow should be sufficient then re-assemble and see what happens. I have done this with 2 regulators and the difference is staggering.
For the first one I did not have a suitable bit of brass and fastened a coper MIG welder nozzle (wrecked) to a punch using an old Citroen pipe seal! The great thing is not to use a steel rod as you will put a flat on the ball and it won't seal.
Incidentally my regulator now cycles at over 1 minute.
jeremy
Earlier I posted a problem about my FDV unit on my XM 2.1 TD. Having read this thread, I am starting to wonder if I also have a regulator problem as I have noticed LHM being deposited around the reservoir even after short trips. As far as I know the hoses are not leaking but it looks like the LHM is coming from the filler cap. Would a regulator that isn't sealing cause variations in steering effort AND intermittent choppy ride especially when driving on a road with dips and rises?
Thanks in advance.
Doc
Thanks in advance.
Doc
When my FDV's were troublesome they always favoured the steering which functioned perfectly. I'm not fully sure how the fdv works as there are no really good explanations of its functioning that I have found.
I did have intermittent steering which was cured by a new pump.
When my regulator was cycling rapidly again this made no difference to the steering.
I eventually found that the pressure relief valve in my FDV was assembled incorrectly and since then the car had performed perfectly. before I had trouble getting enough hydraulic pressure to raise the car etc and found I could fool it by turning the steering wheel so that there was some load on it and the steering stopped recycling and the steering pressure rose and presumably fed the system the wrong way.
Is your LHM level correct? Oil leaks from the return system often mean excessive leakage from a worn component, which overwhelm the return system. Perhaps you should remove pipes from the reservoir and look for excessive return flow?
jeremy
I did have intermittent steering which was cured by a new pump.
When my regulator was cycling rapidly again this made no difference to the steering.
I eventually found that the pressure relief valve in my FDV was assembled incorrectly and since then the car had performed perfectly. before I had trouble getting enough hydraulic pressure to raise the car etc and found I could fool it by turning the steering wheel so that there was some load on it and the steering stopped recycling and the steering pressure rose and presumably fed the system the wrong way.
Is your LHM level correct? Oil leaks from the return system often mean excessive leakage from a worn component, which overwhelm the return system. Perhaps you should remove pipes from the reservoir and look for excessive return flow?
jeremy