The saga continues TZD Hydraulics

oilyspanner · Post by **oilyspanner** » 21 Apr 2005, 19:34

Well as some of you know my TZD has been plagued by the STOP light flashing under braking and when turning right! this happens in conjunction with the low brake pressure light and a relay clicking behind the steering column I have replaced the HP pump four times, yesterday I bought GSF recon one ouch[:(] I have replaced FDV twice with no change of symptoms,the system has been hydraflushed, the LHM is new the filters are spotless perhaps the brakes feel a little sharper maybe but what could it be?
on a brighter note should anyone need a diesel HP pump I have a few in
[B)]
Stewart[:D]

alan s · Post by **alan s** » 21 Apr 2005, 19:53

Can I have first roll of the dice?
Pressure regulator or doseur?? Either one starving the system by allowing too much pressure through when under brakes??
Just a thought, but the best I got.
Alan S

bxbodger · Post by **bxbodger** » 21 Apr 2005, 19:59

It could also be electrical- ever since I disturbed the low coolant level sender's connections, the stop light has come on at odd intervals, particularly when turning corners!
Presumeably its caused by minute movements in the connection due to centrifugal force on cornering, as the coolant level is fine. And despite having remade the terminal, it still occasionally does it-most annoying.........

Post by **RichardW** » 21 Apr 2005, 20:23

Does it do it ONLY when Braking and Turning right? Does it always do it? I am interested in why the 'relay' is clicking. Maybe there's a loose wire shorting to earth somewhere. Could you put a seondary test lamp on the pressure switch on the security valve so you are absolutely sure it is a pressure problem?

oilyspanner · Post by **oilyspanner** » 21 Apr 2005, 20:40

It appears to do it when the oleo system requires volume of LHM from the system, eg when negotiating a smooth type speed bump, I have made and remade related electricals, the relay clicking is exactly timed with the lamp coming on, I have replaced the security valve too! and given the wiring in the area a wiggle, think I will clean up a PR and try that, the rad is coming off tomorrow as I go about the fun task of replacing the turbo so I might as well while Im in there.
Stewart

Post by **Jon** » 21 Apr 2005, 20:55

Check the black Valeo relay that lives by the o/s headlamp (bolted to the front panel by the rad), it controls all the level sensors. The connection gets crudded up and can cause this very fault. Or try swapping it for another one if you have one?

vanny · Post by **vanny** » 21 Apr 2005, 21:01

which realy are we talkking about?
If it's happening when there is a change in direction couldnt it just be fluid getting past the end of the ram? surely that would cause a loss of pressure?
If it's the ABS relay clicking then why not try pulling it and see what heppens?

goldfinche · Post by **goldfinche** » 21 Apr 2005, 21:51

Hello well most of this is speculation but the LHM level indicator is on the right hand side of the tank (looking from the drivers seat)and they have been known to stick and give fause readings, when you go round right hand corners the LHM swills to the left would this lower the level enough to put the light on?? As regards the seeming low pressure I was led a merry dance by a pressure regulator, reseated the bearing but it made no difference a new one restored the brakes to what they should have been.A new doseur valve was found to be leaking worse than the old one I took out!!A check of the returns to the tank may be revealing, also a pressure check.
Cheers and good luck.
Geoff.

oilyspanner · Post by **oilyspanner** » 21 Apr 2005, 23:44

Found the relay, contacts were a bit green, gave it a squirt and a clean, no difference there, will look for one in the breakers, the LHM float is free and reservioris a bit overfull, having to lift the motor tomorrow to get round the back, have cleaned up a PR so will swap that, more extensive roadtest reveals the brakes are no different, they seem to lack bite compared to old BXs but this is the first ABS one I have had, have spare doseur from old GTI will check to see whether it will go?

Post by **Jon** » 22 Apr 2005, 02:59

All the pressure regs are the same provided that the car (BX) has PAS. I can't really see that it could be the doseur from what you say. I've never changed one in nearly 20 years, but hey!
BX with ABS do definately lack bite. I though that there was something wrong with my last one, did discs/pads all round, new LHM, accumulator and pump, and still no better! Present one with no ABS has lovely bite and solid pedal. I guess that if it was me on this job I'd be thinking about getting the pump flow/pressure tested, if all Ok, I'd look at the flow valve as they can divert too much to the PAS and leave the car with inadequate braking. Pretty unlikely though, although didn't you mention some steering problems previously that you thought were caused by a weak pump. Could be a sticky flow valve??? Geoff may have something with his PR theory, if you have another one, stick it on, give it a bleed and see if there is much difference!
Final tip is to chuck the accumulator and fit an XM/Xantia centre front sphere (70 bar)instead, they hold so much more in reserve that they can help the weaker pump or sticky component.

ItDontGo · Post by **ItDontGo** » 22 Apr 2005, 19:15

If it works then why worry

The brake pad light on my car comes on everytime I touch the brakes and I'm still here. For now.
Sounds like something electrical might be connecting when you go right and brake. Things like that look like they wouldn't do it in a millions years when you find the problem.

Oscar Too · Post by **Oscar Too** » 22 Apr 2005, 22:18

Jon if you read this:
I'm hydraflushing (again) my TZD this weekend - didn't do it properly first time round. I'm pretty convinced a weak pump is the reason for sporadic power-steering, so I'm going to swap it with a (I hope)good one from wilkobob.
I'll be replacing spheres all round when I swap back to LHM. Do you think it's worth putting a Xant accumulator sphere on as a precaution and to help otherwise tired and old components?

Post by **Jon** » 23 Apr 2005, 00:13

Putting a Xantia accumulator on will make no difference, as its still 62bar, same as a BX. To help an old pump you need an XM/Xantia front hydractive centre sphere, which is basically an accumulator offering a larger volume and 70 bar.

oilyspanner · Post by **oilyspanner** » 23 Apr 2005, 06:27

Well here I am after a whole day under the BX, First I swapped the PR. then I lifted the engine and pulled forwards after removing the long driveshaft, swapped turbo, its horribly oily back here, put in a new bottom mount, and put it all together again, initial roadtest , livelier, growlier intake noise more boost than old turbo, turn right , light flashes, brake heavily, light flashes, the car is working well, will pursue electrical next.
Stewart[V]

oilyspanner · Post by **oilyspanner** » 23 Apr 2005, 14:07

Just having another attempt to upload images,Jon I hope theyre small enough

As you can see I have the usual untidy garage that goes with BX ownership, todays mission is to clean my oily dabs off the wings, check for LHM leaks etc and to see how much boost the new Garret turbo is making, and adjust fuelling to suit if neccesary, the first image shows that there is enough room to remove the turbocharger with the engine in situ, you just need to remove the radiator and disconnect things like fuel lines to allow the engine to come forward, on my travels I found two hoses that were about to fail, one attaching to the expansion bottle and one of the braided ones behind the engine, a rummage in the pile revealed almost two sets of these![:D]