Bx Handbrake / Front Caliper

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

Post Reply
ghostrider
Posts: 360
Joined: 05 Jan 2002, 01:10
Location: United Kingdom
My Cars:
Contact:

Bx Handbrake / Front Caliper

Post by ghostrider »

Hi Guys,
Yes its MOT time again and as usual, I'm out of time to do it and predictably enough whilst doing the things I knew needed doing I've run into an unusual problem.
About 6 months ago my right hand front caliper packed up, got an exchange from A&D treated myself to some new Handbrake cables, discs, pads. Everything worked fine.
For some time I've had the feeling that the handbrake was not all it should be, and when I tested it by the simple expedient of turning the front wheels with it on the new caliper appeared to be not working at all.
So I took the pads out, wound the piston back in, reinstalled pads, went through the adjustment procedure ( Foot hard on brake a few times with engine running) having made sure that I'd not overdone the cable adjustment, ( In fact I disconnected the cable to be sure) hand brake on, nothing [:(]. Went through the whole procedure again only this time I tried operating the handbrake lever before I put the pads back in and the piston duly moved out OK, So why when I put all back together doesn't it work?
It almost like the auto adjuster is not working but there is no sign of water getting in and the handbrake lever operates the cam agaisnt the pushrod to the piston OK. But as soon as the piston moves out to take up the wear in the pads (less than half worn) the B****** thing stops working.
Faulty Caliper or have I missed something?
Pete
________
Synthetic Weed
User avatar
AndersDK
Posts: 6060
Joined: 21 Feb 2003, 04:56
Location: Denmark
My Cars:
x 1

Post by AndersDK »

I donno why -
But for some odd reasons it's widely thought that just applying the brake pedal violently hard will adjust the handbrake.
This is NOT the case ! [8)]
To adjust the BX (& Xantia) handbrake :
Press & hold the pedal down firmly (NOT hard or violent !!).
Then with your tumb keep the handbrake button released while you work firmly up/down the lever between stops.
You'll soon begin to feel it resists going high up - taking the end stop lower & lower. Don't try to force up to the same high end stop position each time. The resistance felt lower & lower down indicates the handbrake is adjusted.
When the ratchet takes about 3 clicks on the BX for the handbrake applied - it's about right. Trying to adjust it further will be too much.
On the Xantia the first travel ratchets has been removed - so a Xantia handbrake working on it's first click applied is just about right.
ghostrider
Posts: 360
Joined: 05 Jan 2002, 01:10
Location: United Kingdom
My Cars:
Contact:

Post by ghostrider »

Thanks Anders, just been out and tried it, unfortunately still no go, the old calliper has adjusted up OK but the new one is just the same, must be faulty I guess
Pete
User avatar
AndersDK
Posts: 6060
Joined: 21 Feb 2003, 04:56
Location: Denmark
My Cars:
x 1

Post by AndersDK »

Pete -
Our friend ShaneL (DoubleChevron) from ozzie has been there - tried it.
Look at his pictures from the work :
http://www.aussiefrogs.com/shane/bx/bx_handbrake.htm
User avatar
uhn113x
Posts: 1161
Joined: 06 Jan 2004, 22:06
Location: Near Leeds, United Kingdom
My Cars: 1981 Dyane - on road all year round.
1982 GSA Pallas - on road April - September.
1997 ZX 1.9D Dimension.
x 1

Post by uhn113x »

Hi Anders
Curiously, I have always adjusted handbrake on my BX by pressing very hard on pedal with handbrake off - I thought that it pushed the small piston inside the caliper towards the outside and turned the rotating bit inside the one-way spring. It has always worked! Just tried your method, and that does, as well! :)
Incidentally, my carb seems OK since I repaired leak in AF vacuum reservoir - had to adjust stop so that choke flap opened about 10mm, though
Mike
User avatar
AndersDK
Posts: 6060
Joined: 21 Feb 2003, 04:56
Location: Denmark
My Cars:
x 1

Post by AndersDK »

Well -
Since your footpressure has nothing to do with the actual brakeforce - there is no reason to strain the pedal box [:)]
- especially as RHD BX'es have a weak pedal box [;)]
Remember that the brake valve in principle is just a tap for the LHM fluid under pressure in the system - nothing like the "normal" systems with a piston pressing out the fluid by your footpressure.
Once the pads are engaged with the discs by a light foot pressure - the pads/pistons won't move that many micrometers more by opening the tap fully - i.e. pressing further on the pedal. It's just the force applied to the pads that increases by a fully open valve.
Why use violence ?
It was never thought to !
nick
Posts: 1079
Joined: 14 Mar 2001, 01:49
Location: Market Rasen, Lincolnshire
My Cars:

Post by nick »

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">Since your footpressure has nothing to do with the actual brakeforce - there is no reason to strain the pedal box
- especially as RHD BX'es have a weak pedal box
<hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote">
Quite right, in an attempt to adjust the handbrake I once managed to bend the brake pedal in half on an elderly BX by putting far too much force on it ! [:I]
AdrianO
Posts: 9
Joined: 28 Apr 2002, 17:05
Location:
My Cars:

Post by AdrianO »

Handbrake problem affecting new caliper.
A refurbished caliper I obtained had these notes attached:
* Do not operate handbrake lever before fitting to vehicle. The unit has been pre-set at the factory. If you have, go to last paragraph.
which reads...
* To reset the handbrake mechanism if the lever has been operated before fitting then the piston should be turned "in" using the above methods. When the piston is fully "in" then the piston should be turned "Out" by half to 1 turn. The handbrake mechanism is now set.
"above methods": use allen key or long-nose pliers to rotate piston. In both cases, if piston is wound in at any stage, it should be wound out half a turn to reset internals.
Worth doing... my BX slid off its handbrake before I knew about the above.
User avatar
AndersDK
Posts: 6060
Joined: 21 Feb 2003, 04:56
Location: Denmark
My Cars:
x 1

Post by AndersDK »

Except that it is correct the piston MUST be turned - it sounds a bit odd this description Adrian [8)]
All it says is that if you move the lever arm on the caliper - the piston will of course move out.
This has nothing to do with "setting" the handbrake - but simply may restrict the insertion of the pads.
And then the piston must be "reset" by turning it in again - to allow insertion of pads - naturally.
Once the caliper, disc & pads are fitted - it is in fact advantageous to work out the piston using the lever - to bring the pads in contact with the disc - before the handbrake cable is fitted.
RichardW
Forum Treasurer
Posts: 10812
Joined: 07 Aug 2002, 17:12
Location: United Kingdom
My Cars: MK2 '17 C4GP 1.6 BlueHDi 120
'13 3008 1.6 HDi GripControl
x 983

Post by RichardW »

Anders,
Application of the foot brake definitely does adjust the handbrake[:)] No 'violence' needed, just press it a couple of times as if you were making an emergency stop, and the handbrake will come up nice and short. Try it next time you have a 'long pull'[:o)]
In any case, if there was risk of the pedal breaking away or bending, I would want it to happen whilst I was adjusting the handbrake in the drive rather than on the open road when I <i>REALLY</i> needed the car to stop....[:D]
ghostrider
Posts: 360
Joined: 05 Jan 2002, 01:10
Location: United Kingdom
My Cars:
Contact:

Post by ghostrider »

Ok Guys,
Swapped the calliper for a second hand one off one of my collection of non runners and it works, so I can only presume that "new" one is faulty. Thanks for Shane's site Anders, the photos would seem to indicate that I have the same problem as he did, I haven't dismantled it to check as the nice people at A&D have said they'll replace it, if it is faulty, thanks for everyones help
Pete
________
Suzuki Rm Series History
Last edited by ghostrider on 22 Feb 2011, 05:46, edited 1 time in total.
Post Reply