BX hydraulics????

pmhpmh · Unread post by **pmhpmh** » 23 Aug 2005, 22:48

When going round a tight right hand bend I get a momentary flash from the STOP and Brake warning indicators.
The tighter the bend and the faster you are travelling the longer the warning stays on, altho I am talking less than a second.
My initial thought was for low LHM, but it all appears ok.
Next thought was power steering taking all the available pressure hence reducing braking pressure available. However Steering load (when stationary) alone gives no symptons.
Next thought is it possible that a suspension strut is leaking back fluid when under heavy load only? Is this possible and how can I test it?
Brakes appear to be fine altho difficult to prove when fault? is only apparent when going fast round a very tight bend.
No other symptoms, all hydraulics are working well.
(PS brake wear contacts are not connected, hence I think electrical can be discounted, and I assume that this would not operate STOP indicator anyway).

DLM · Unread post by **DLM** » 23 Aug 2005, 23:21

This IS almost certainly a sign of low(er) lhm level. When you take a right-hander the LHM will be forced to the LH side of the reservoir, causing a temporary drop in the level on the RH side. Try a small topup of LHM and see whether there is any difference. Drops in level can sometimes occur even in a hydraulic-leak-free car as the spheres age and the resultant loss in sphere pressure causes more volume to be taken up by LHM because of the less "inflated" sphere diaphragm.

pmhpmh · Unread post by **pmhpmh** » 23 Aug 2005, 23:41

That was my thought. I have just rechecked, and fluid level is on the high side- I topped it up at the roadside when it first happened. I suppose the level switch could be faulty? ie measuring low?

citronut · Unread post by **citronut** » 24 Aug 2005, 00:22

do you know you can only properly check LHM level with car on level ground and fully up on the highest setting,then the yellow disc not the copper one should be between the two red bands on the clear plastic dome,if it is above the top line this is ok it might just make a mess when susp goes right down,also all that puts the light on when tank is low is the copper disc shots across two contacts at the base of dome,so it seldom is at fault
regards malcolm

oilyspanner · Unread post by **oilyspanner** » 24 Aug 2005, 00:36

Having chased a very similar problem on my BX including pump, regulator, FDV swaps I now use the digit(al) method and the problem seems to have disappeared. An extra litre of LHM and ignore the stuck float.
Stewart

pmhpmh · Unread post by **pmhpmh** » 24 Aug 2005, 00:37

Yes - level checked and topped correctly. Does the level indicator also trigger the brake warning light as well as the STOP? I will check the wiring diagram later.

Unread post by **Peter.N.** » 24 Aug 2005, 03:47

Have you checked your water level?

G4EIY · Unread post by **G4EIY** » 24 Aug 2005, 04:08

This can happen even when the LHM level is correct.
At the bottom of the indicator tube there should be fitted a plastic cap, somtimes this cap comes off.
This cap acts as a damper on the fluid level change due to centifugal force on cornering etc.
Check this is still in place.
This can be done insitu with care, the indicator tube is just fixed like a bayonet light bulb...
But will require the tank to be moved slighly into the engine bay to enable the Indicator to be removed.
Then check that plug is still in place at the bottom of the tube.
Note! Remove the two electrical wires from the indicator first, and reconnect after the check.
Cheers