406 strange braking

np · Post by np » 11 Sep 2008, 20:06

Hi to all,not been here for a while so hope everyone is ok.
I seem to have a fault under braking.Not had time to look yet,but pads & disks look to have another 5k or so miles left.This only happens the last 10 or so feet when coming to a halt,but i get a strange judder through the peddle & a noise from the front,just like the ABS is cutting in.It does`nt do it every time,only about 50%.ABS is working fine as i tried it tonight.
I dont know if its related,but it seamed to start happening last week when i started bring about 100kgs of stone home in my boot,i thought because of the weight & the wet roads it was the ABS,but it does it even when empty.
Hope someone can point me in the right direction before i start looking on sat.
Cheers,Neil

reblack68 · Post by **reblack68** » 12 Sep 2008, 05:45

Maybe the load compensator has got stuck in the "loaded" position giving you too much braking at the back end and setting off the ABS.

Post by **CitroJim** » 12 Sep 2008, 08:18

Good thinking Richard. The compensator is a good first port of call...

It'll be wiorthwhile checking over the vacuum pump and servo.

With the engine off, pump the brake pedal until it goes rock-hard. Keep your foot on the pedal as you start up the engine. As vacuum builds, the pedal will sink a little.

citroen7 · Post by **citroen7** » 12 Sep 2008, 11:08

my 405 has just failed the mot because the compensater was not connected to the axle via the spring and i used to get the same problem with the brakes ,so i bought a new compensater and was going to swop them but could not get the brake pipes undone so i just swopped the spring over and bled the brakes and bingo all works perfectly took the car up the road and slammed on the brakes and no pulsing through the pedal
The set on the 406 is slightly different according to my cd manual as i was going to go to the scrappy and take some bits off a 406
you are supposed to get the system cheked out to make sure the system is properly balanced but i just counted the threads and put the new one on the same . hope that helps!

np · Post by np » 15 Sep 2008, 21:27

Thanks guys.I`ve had a look in the BOL`s & it mentions the spring.I`llhave a look this weekend coming.I do a lot of towing,but the down pressure is only 70 odd kgs,& my chippings that i`m bringing home are proberly 120 ish kgs.So what you say makes sence.Will keep you informed,cheers,Neil

v8disco · Post by **v8disco** » 27 Sep 2008, 10:05

Hello mate

I am 99% sure this is the same problem I had on my y rev 406 hdi.

What had happened is that both abs rings on the front cv joints had split and from time to time were spinning on the cv joints . This told the abs ECU that one or both front wheels had locked and the abs cut in.

There was no pattern to it happening. Might do it every time then not for 2 or 3 days. I tried spot welding the rings back but no joy. Ended up having to fit 2 new outer cv joints which came with the rings ready fitted. Completely cured the problem

Cheers. Martin

v8disco · Post by **v8disco** » 27 Sep 2008, 10:09

Hello mate

I am 99% sure this is the same problem I had on my y rev 406 hdi.

What had happened is that both abs rings on the front cv joints had split and from time to time were spinning on the cv joints . This told the abs ECU that one or both front wheels had locked and the abs cut in.

There was no pattern to it happening. Might do it every time then not for 2 or 3 days. I tried spot welding the rings back but no joy. Ended up having to fit 2 new outer cv joints which came with the rings ready fitted. Completely cured the problem

Cheers. Martin

np · Post by np » 03 Nov 2008, 20:15

Well the problem seems to have gone.It was still doing it on & off for the MOT in late Sept,but passed fine.Never got around to looking into it as i`ve been working away since Sept.Just seems tohave cured its self.
Thanks anyway