MOT fail

[KennyW]

Good morning All,

Took the girl for its MOt and it failed on brake efficiency and r/n/s running uneven.

I think there is still some air in the system which needs to be removed, hopefully that will cure efficiency problem.

It would appear to be the Hub bearing which is gone causing the uneven wear.

It explains fully the shuddering brakes I had prior to changing the discs and pads on the rear. After changing pads and discs the shudder had gone. The tester I know very well said this would only have been felt on the rolling road.

Fortunately he said the rest of the car is fine. Also not a dear fix will get part today and between rain showers try and fix tomorrow evening.

Kenny

[citronut]

can you feel play in the bearing then,

what brand/quality of pads did you fit,

regards malcolm

[RichardW]

Air in Xantia brakes doesn't usually cause low efficiency - they just take a while to come on, by which time the operator has the pedal jammed down, and you smear your head all over the windscreen.... I'd be thinking stuck calipers, or poorly bedded pads (although you fitted new discs I think?) or ABS problems. Try a couple of paving slabs in the boot to see if that improves things!

[CitroJim]

The rear hub is not too bad as long as you've had calipers/discs off recently You need one of those cheapy hub pullers that bolt across to wheelstuds and has a bolt through the middle. The inner race usually comes off with a flat bearing puller.

Just mind the ABS sensor as it's a tad exposed and vulnerable...

Use a mandrel to drive the new hub onto the stub axle, driving on the inner race...

[citronut]

Try a couple of paving slabs in the boot to see if that improves things!

or just put the suspension fully up on high,

did you use heat on the calipers to free the bolts off, if so maybe the seals became overheated,

did a strong full flow of fluid come out of the rear caliper bleed nipples when you bled them,

regards malcolm

[xantia_v6]

I had a Xantia which was always marginal on rear brake efficiency (failed 2 out of 3 MOT tests) due to the previous owner fitting Brembo pads which were just too hard and slippery. If you don't know the quality of pads fitted, a new set of genuine or equivalent pads may be a good investment. I have never had a problem with Mintex pads, and they are available reasonably one ebay.

Putting weight in the boot does not help, as the brake test machine compensates. I tried this with the above car by putting 250kg of bricks in the back, and the MOT brake test gave exactly the same reading as without the load.

[KennyW]

Thanks for the replies,

When I did the rear brakes no heat was used to remove calipers, 1 bolt snapped and the other 3 came off. But I have not bled the system fully yet hence my thinking about air.

The r/n/s was a jet of fluid and blew the pipe off when I put the recon caliper on but I was running low on the green blood
Obtained new supply, intending to do rear hob and bleed at same time.

Just annoying that the efficiency result was 49%

Kenny

[KennyW]

Hi Guys,

Can the front calipers leak internally or/and perished seals within cause this problem

Kenny

[CitroJim]

Can the front calipers leak internally or/and perished seals within cause this problem

They can Kenny and it's normally indicated by the boot on the back of the caliper becoming full of LHM...

[KennyW]

Thanks Jim,

That's what I was thinking, Is it worth doing a complete seal overhaul on the calipers

Kenny

[citronut]

i dont think they are easy to overhaul, there is a pack of conical spring steel disc's/washers which require compressing,


regards malcolm

[KennyW]

Ladies and gents,

Managed to sort out rear wheel hub on sunday prior to rain falling.

Took the old girl in for her MOT and she passed. The braking had improved enough for her to pass I suspect partially due the pads having bedded in a bit more but there appears to be new disc warped. although not sufficient to fail. It was suggested to swap over discs to check.

Kenny

[CitroJim]

Took the old girl in for her MOT and she passed.

Kenny that's excellent news