Front brake flexi hoses and rear caliper question Xantia VSX

[admiral51]

Hi all
As the title suggests i need some advice

My VSX failed its MOT on rear brake test 44% and both front flexi hoses plus a few minor issues

First question is the flexi hoses i know i can get them from GSF but i dont have pukka brake spanners the ones i have are open ended but have what i call a witches nose (im trying to be descriptive ) on them and seem to do a good job on the HP unions will these be ok in your esteemed opinion

As for the rear brake failure i want to split the calipers and give them a good clean do i need to get any seals for this particular madness 8) 8)
I did overhaul them about 3 months ago but guess i may not have done it quite right

I have just been out and done some citrobics and found that the rear end is jumping/bucking when i go from high to normal could this be air in the brake lines
To clarify before im asked just as the rear end settles to normal height it jumps back up to near high setting then continues to drop to normal or will this be a sticky height corrector

Thanks in advance

Colin

[DickieG]

I dont have pukka brake spanners the ones i have are open ended but have what i call a witches nose (im trying to be descriptive ) on them and seem to do a good job on the HP unions will these be ok in your esteemed opinion

That's the eternal question of how long is a piece of string? Of course your present spanner will be find unless it rounds the corners then you'll know you should have used a flare nut spanner!

I have just been out and done some Citrobics and found that the rear end is jumping/bucking when I go from high to normal could this be air in the brake lines
To clarify before im asked just as the rear end settles to normal height it jumps back up to near high setting then continues to drop to normal or will this be a sticky height corrector

This is more than likely due to a sticky rear Hydractive valve, but as with my answer above, giving the rear brakes a good bleed will eliminate the possibility of air.

Rear brakes on Xantia's do appear to be quite marginal with the MOT test, for instance my V6 has genuine new pads and disc's, no corrosion between the caliper and arm, they have been bled to death yet came close to failing the test

[CitroJim]

For the flexis Colin, a 14mm Ring will likely be essential to undo the caliper end as they do well corrode in. Any open-ender is likely to round off the corners.

As you're replacing the flexi anyway, cut the rubber part of the pipe near the caliper so you can use a ring (or good deep socket) on it.

'Tother end is not usually a huge problem but a good hex flare nut spanner is essential here unless you are fortunate. Normally, the LHM prevents any significant corrosion and often this end receives fortutious corrosion protection from oil leaks in the engine! They are usually tight though. I can't recall if the spanner you need is a 10 or 11mm now.

As for rear brake efficiency, it helps to present for MOT with a heavy weight in the boot to make the suspension work harder and thus provide more braking pressure.

The MOT tester is permitted to make allowances for rusty discs (on an otherwise sound system) which he knows (if he is skilled at his job) will not be anywhere near as efficient as well-used shiny ones.

[Stempy]

I am going to undertake this job myself today. A complete overhaul kit was £54 from Citroen which includes 4 bolts, two pins, 8 seals and 2 O rings. I already had the Cit pads and brembo discs (original items from ebay). My MOT is due any minute so having already done the fronts it's time to do the rears. Might be an idea to put something heavy in the boot for the test.

The front flexi hoses came off ok on mine with no rounding off but I do have a flare nut spanner, might be as well to invest as they are not too expensive, even from Hal****. And give 'em a good soak in plus gas or similar.

[citronut]

the pipe nut at the top of the flexi (metal pipe end) is usualy 8mm on most hydraulic citroens, these pipe nuts are very soft and do round off at a blink of an eye if your not very carefull,

if however you do have 11mm nuts these are a bit harder metal and take a bit more efort to round off,

make sure you salvage to old pipe seal/s from the top end of the flexi/s,
unless you have bough new seals

and if reusing the old ones just pull/peal any strands of rubber off before re/fitting them, as you dont want any stray bits of pipe seal entering the system,


rear brakes if you can convince your MOT tester that to test the rears the suspension needs to be on high, it should pass with flying colours
regards malcolm

[CitroJim]

make sure you salvage to old pipe seal/s from the top end of the flexi/s,
unless you have bough new seals

Ahh, now that's interesting. All the ones I've done have had no seals (that I was aware of) and had the more conventional mushroom flare. Certainly no rubber seals. Was that on early ones Malcolm as I have a feeling the pipes were different on those?

Mind you, it was only by going to Pleiades I learned that the fine thread regulator has a metal seal on the 12mm union so if there are removable seals in the ends of the flexis, I won't be surprised.

[Thermonuclear]

A full tank of fuel should help to improve rear brake performance on an MOT. 65L of petrol is 45Kgs and diesel would be over 50Kgs.

[citronut]

maybe its just non ABS xants which have the 3.5mm pipes with 8mm pipe nuts and seals

regards malcolm

[Stempy]

Not as much progress as I'd hoped due to a sheared bolt. Tried to drill it out, all was going well, then the drill snapped So then I had to drill from the other side and use a punch and a big hammer to drift out the snapped drill.

Then, when I let it off the jack I forgot about the idiosyncrasies of the HA suspension, so although I had it on high setting, because the rear wheels had been off the ground the rear was still on low. Unfortunately I had left an axle stand a little too close to the back of the car and as the whole lot collapsed to the low setting the stand was caught under the rear bumper so it got a bit squashed and crazed the paint.

And to top it all, I sat on my phone and broke the screen.

So, as a result I only got one side done. Hopefully the weather will remain fine so I can do t'other side tomorrow. Or perhaps I should just stay in bed.

[admiral51]

Have managed to do the front flexi hoses today ran out of time to start on the rears that is a job for tomoorow

As the consenus was to obtain the pukka tools i duly went and aquired some and i have to say well worth the money

Both 11mm unions were undone with minimal fuss and even the 14mm ones gave way without the need to chop the pipe off

Now lets see what MOT man has to say

Have given the rear brake problem a bit of thought and i think that when i did overhaul them one of the pistons came out not 100% sure if it was the VSX or the TD as i did both around the same time

I remember just pushing the piston back in but having scoured the forum past posts someone said if the piston comes out then the caliper needs to be filled with LHM as otherwise they are a PITA to bleed.
Any ideas on this particular theory welcome

Also when i did overhaul them on the VSX i didnt change disks or pads but reckon if it failed on them once then i ought to do a complete change and a real good bleed so will get pads and disks on monday (thought earlier i would get away with a thorough bleed ) but tomorrow the old stuff will come off and give the calipers a good clean

Thanks for the tips most welcome

Colin

[CitroJim]

Then, when I let it off the jack I forgot about the idiosyncrasies of the HA suspension

Sorry to hear that Stempy Something I discovered the hard way by trapping a jack under the car. It really banged down on top of it. I now always jack down very slowly and if it is going to collapse I stop and wait for the height corrector to do its thing and raise it again. Often this can seem to take a long time though..

Still, an Activa at the rear can be even worse and I find it is necessary to use two trolley jacks (one each side) and lower both down gently.

Hope the bumper is not too badly damaged..

Tomorrow is going to be a bit stormy so choose your time and you'll be fine...

All the best for the MOT Don't forget to leave something heavy in the boot!

[xantia_v6]

All the best for the MOT Don't forget to leave something heavy in the boot!

When the rear brakes on my Mk2 V6 failed MOT earlier this year, I tried cleaning the disks and pads with brake cleaner, and gong for a re-test with 150kg of concrete blocks in the rear of the boot.... but the brake reading was unchanged from the previous test.

I wonder if the brake testing machines take account of the axle weight?

I got through the test by roughing up the disks and pads with an orbital sander, but it takes a while to bed them in afterwards.

I have never had a problem with the rear brakes on my Mk1 V6, does the Mk2 have a different Doseur valve or something?

On the subject of brakes, I bought a set of these Mintex front pads pads from ebay for £33 including postage. Although said to be for a Xantia V6 estate (the unicorn of Xantii??), they are the correct part. they bedded in nicely to the old disks, are quiet, and stop well.

[Stempy]

The MOT brake tester does take into account the axle weight, the stopping force is worked out as a percentage of that.

I was tempted by those Mintex fronts but I ended up going for Bendix OE pads from Euro @ £36.

[citronut]

the best way to bleed hydraulic citroen rear brakes is with suspension set fully up on its highest setting, then you will get full brake presure flowing through the system,

i usualy place two slabs of timber staged under the rear/front wheels of XANTIA's before lowering to the ground whith evacuated suspension presure,

this way you can let the car right back down onto its bump stops and still get the jack out,

regards malcolm

[admiral51]

Had a reasonable day so thats good

Both rear disks and pads removed and binned should have done that in the first place

Managed to give both calipers a real good clean and even managed to get the pistons to come right out without splitting the caliper
The best way to achieve this is to remove pads and disk and then have the brake pedal pressed whilst forgetting to have a wedge in the way of the pistons
Turned out ok though as was able to clean the pistons and calipers better than my earlier attempts.Both rears have now been bled properly using my long bleed pipe returning it straight to the LHM resevoir and just need to fit the disks and pads tomorrow assuming GSF have them in stock
Thanks for all your help and fingers crossed it will pass inspection this time

Colin