doseour valve

[martscar]

Hi all. I have only just found this forum despite having had 2 Peugeot 305 diesel vans for 10 years each ,and my Citroen Xantia 2.0 hdi for the past 11 years. Better to find it late than never I suppose .
I have changed all spheres and front discs/pads but on the last M O T the guy said it only just passed due to poor brake efficiency. There is no delay on them and I have bled the front but did not see any air. I have done the boot sit after turning the engine off and it rises well
Does anybody know what besides air can cause low pressure on the brakes. To me they seem the same as always but I think the test has changed. I would dearly like to sort it out, the car is otherwise a joy

[Hell Razor5543]

Did the MoT guy say which brakes were at issue? The reason is that, due to the way the system is set up, if the back of the car is light then there is very little force on the rear brakes, but this increases when the weight does.

There is also a known issue with the rear callipers caused by weird corrosion between the calliper and trailing arm;

http://www.frenchcarforum.co.uk/forum/v ... =3&t=38467" onclick="window.open(this.href);return false;

[martscar]

Hello and thanks for your imput. He said it was the front which I set about bleeding.I have the feeling that I'm missing something,Regards,Martin

[citronut]

hi and welcome

as James says really,
at the end of the day the brake testing has not really changed on the MOT by very much at all,

the usual story though is these problems gradually increase over time, so the owner/driver forgets how impressive the brakes/suspension used to be,

hydraulic citroen brakes are usually second to non, even with worn our pads and the likes,

on fitting the new front brakes did you firstly unhook the hand brake cables from there levers at the calipers,
then wind the pistons back in the correct fashion,

did you have a good strong flow of citro blood from the front calipers,

if not maybe the front flexi hose's are collapsing internally

were are you located

[xantia_v6]

If the poor efficiency started after you changed the pads, then i would suspect that the pads have the wrong spec for the car. I had a xantia that struggled every MOT with rear brake efficiency, The previous owner had fitted 'high performance' pads that had very little grip when cold.

[martscar]

Hello and thanks for responding. I didn't disconnect the handbrake cable when replacing the front brakes, could this affect them?. You are right when you say that we don't realise how things change in slow mo, when I think back it was very easy to over brake in the beginning.
The fluid flow seemed good ,but as I have 2 new hoses it is worth changing them, especially as the fella listed hose cracking on the notes. Is there anything special to watch for when changing them please.
Oh, and I am in Medway,kent

[martscar]

Back again, forgot to say the pads were standard as far as I know but that is a good point..I got them from Eurocar parts and they never gave a choice or option on hard /soft. They just don't have that secure feel you get when working ok, as though pedal pressure is irrelivent
Cheers,Martin

[citronut]

i think if you dont disconnect the cables before winding the pistons back, it would only affect the hand brake effort, as it can cause the hand brake mechanism not to be able to re/set its self on winding them back, this should not affect the foot brakes effort though,

on replacing the flexi's the flare nut to flexi ( metal pipe end ) can be a bit of a BBB to undo, a very good fitting flare nut spanner is useful here,
the ones i have done so far on XANT's have had conventional brake pipe flares at this point

[citronut]

I got them from Eurocar parts

that could well suggest they are poor quality IMO ,
regardlees of the brand the brand printed on the box's

[martscar]

OK so it seems that I may have inferior pads. The handbrake works well .At least I have a start point and am tempted to re bleed the brakes ,although there is no obvious delay. I presume pads from Citroen would be your choice. Thanks for your advice. Martin

[addo]

Taking into consideration the rear corner spheres, the rear "anti sink" sphere and your accumulator, what are the ages of these and when were they last tested?

[Hell Razor5543]

Based on the OP, I believe all spheres have been replaced.

[martscar]

Hi, all corners were replaced 2-3 years ago. I cleaned out and changed the fluid around the same time so they have only done about 15-20,000.Accumulator was changed mid last year. There is no fluid loss. The brakes do work reasonably, but to pass needed 50% and I think mine were about 52% after several goes..Martin

[Hell Razor5543]

What is the mileage of the car? Citroen suggest the LHM is changed every 36,000 miles, and every 3rd change is preceded by a hydraflush cycle. Hydraflush is a fluid that, while it acts like LHM, also has cleaning agents to clean out the pipework, etc. You change the fluid as you would normally, but you only run for between 1,000 miles and 3,000 miles before changing back to LHM. Hydraflush is not as 'greasy' as LHM, so if it is used for too long things might start to bind.

Have you changed the rear anti-sink sphere? It is mounted behind the spare wheel, and is not like the other spheres. It has a pipe screwed into it, and is mounted onto a (somewhat flimsy) bracket.

[martscar]

I'm afraid that I must admit to not having flushed it at all despite having done 140,000 miles so it seems that my to do list is growing. Before I start changing parts, this would seem a good place to start as it must need doing. Would this cause low brake efficiency, could this alone be the answer?.Even if not ,it will get done as I feel a bit embarrassed at my lack of knowledge..The rear anti sink was done with the corners