Front caliper query

BX Tech talk
Post Reply
User avatar
cauchoiskev
BXpert
Posts: 282
Joined: Mon Aug 15, 2005 11:36 am
Location: France

Front caliper query

Post by cauchoiskev »

Alceste just passed the (French) MOT. Hurray !

However, I had to bodge the handbrake by fully adjusting for slack at the caliper. The auto-adjust mechanism has never worked on this car, left and right sides seem to be identical.

Looking at the construction of a caliper, I had thought maybe the washer springy things under the rubber hood might be shot, but on inspection they seem A-OK.

So the only alternative seems to be the ratchet mechanism itself, i.e. the bits inside the piston.

Has anybody opened up a front piston, or had this type of problem ? It's no big deal, but I would like to solve it...
Tinkley
1K Away
Posts: 1502
Joined: Sat Jun 06, 2009 11:27 am
Location: N Hants England
x 8

Re: Front caliper query

Post by Tinkley »

I'd be tempted to try bleeding the pressure reservoir ie slackening the regulator screw etc and getting rid of any air. Then bleeding both front brakes, it may well be a little bit of air is trapped in the caliper. Fairly simple to do and definitely worth a try.
User avatar
JayW
1K Away
Posts: 1590
Joined: Thu Dec 07, 2006 6:40 pm
Location: Now listen here you mullet...
x 13

Re: Front caliper query

Post by JayW »

Are you aware that it's customary to need to apply hard pressure to the pedal several times (as in emergency stop style) for them to adjust?
I have zero patience for your tedium.
User avatar
Jaba
1K Away
Posts: 1893
Joined: Tue Jul 05, 2005 7:54 am
Location: Usually in the garage
My Cars: BX GTi, C3 Auto
x 80

Re: Front caliper query

Post by Jaba »

Well, I have had his problem too. I have opened up the recalcitrant caliper and reassembled it with no benefit.
I have concluded that it is just simpler to replace the failing caliper with an eBay one and then move to the next thing.
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
User avatar
cauchoiskev
BXpert
Posts: 282
Joined: Mon Aug 15, 2005 11:36 am
Location: France

Re: Front caliper query

Post by cauchoiskev »

The brakes themselves work fine, no air in the pipes, only the handbrake gives problems. I have repeatedly tried the pedal/lever manipulation to get the thing adjusting, no dice. I also screwed the pistons in as far as possible, hoping that would free up the mechanism.

@Jaba, did you dismantle the internals of the piston itself ie the ratchet mechanism ? Nothing looked amiss ? TBH, I find it difficult to imagine what could fail, as it's all permanently drowned in LHM...
tim
BXpert
Posts: 324
Joined: Thu Apr 22, 2010 5:51 pm
Location: somerset
My Cars: 2 1992 BX TXD estates
x 1

Re: Front caliper query

Post by tim »

I had exactly the same problem last year and it hasn't gone away. I put a thread up about it and although I got some useful advice it didn't solve the problem in that I was advised NOT to take up the excess slack on the caliper arms, but unless you do this there is no other way to remove this slack. I have measured the cables inners and outers and they seem to be perfectly within parameters. So obviously we are missing something. I have tried the usual pedal stamping but it had no effect whatsoever.
Brian
BXpert
Posts: 441
Joined: Sun Jan 08, 2006 5:53 pm
Location: Bedfordshire UK

Re: Front caliper query

Post by Brian »

Hi Folks,
I think that I have replied with this suggestion before, but can't find it, so here it goes again:

There is a small spring that resides inside the piston that sometimes breaks,
the protruding piece of this spring sheers off.

If this happens, then the handbrake will not adjust.

I will see if I can take a picture to help..

Cheers
Last edited by Brian on Tue Jan 21, 2014 10:36 am, edited 2 times in total.
Visa 17D 1986 192K Sorn
BX 17RD 1986 220K Scrapped 2013 - Too much rust.
BX 17TZD 1992 192K
306 XRDT 1996 175K
User avatar
Jaba
1K Away
Posts: 1893
Joined: Tue Jul 05, 2005 7:54 am
Location: Usually in the garage
My Cars: BX GTi, C3 Auto
x 80

Re: Front caliper query

Post by Jaba »

cauchoiskev wrote:The brakes themselves work fine, no air in the pipes, only the handbrake gives problems. I have repeatedly tried the pedal/lever manipulation to get the thing adjusting, no dice. I also screwed the pistons in as far as possible, hoping that would free up the mechanism.

@Jaba, did you dismantle the internals of the piston itself ie the ratchet mechanism ? Nothing looked amiss ? TBH, I find it difficult to imagine what could fail, as it's all permanently drowned in LHM...
Yes I took it all out. It seems that it is all controlled by the internal spring around the central threaded shaft.
Mine was not broken as Brian suggests so as I said before dunno.
The Joy of BX with just one Citroën BX to my name now. Will I sing Bye Bye to my GTI or will it be Till death us do part.
User avatar
cauchoiskev
BXpert
Posts: 282
Joined: Mon Aug 15, 2005 11:36 am
Location: France

Re: Front caliper query

Post by cauchoiskev »

Brian wrote:Hi Folks,
I think that I have replied with this sugestion before, but here it goes again:

There is a small spring that resides inside the piston that sometimes breaks,
the protruding piece of this spring sheers off.

If this happens, then the handbrake will not adjust.

I will see if I can take a picture to help..

Cheers
Thanks Brian, I did do a search, but didn't see your post...

That spring does not seem to be included in any repair kit, and is not even shown in the BX parts list. Doesn't sound promising.
citronut
Over 2k
Posts: 2781
Joined: Wed Oct 31, 2007 7:55 am
Location: EAST SUSSEX UK
x 1

Re: Front caliper query

Post by citronut »

have you tried with the front wheels off, disconnect both cables from the calipers, then start the engine and press very hard on the pedal a few times,

make sure the levers on the calipers are returning to the fully off position, before trying the above,
because the hand brake mechanism canot adjust all the while the lever in pulled on in the slightest, by the cable being over adjusted or the lever sticking up/on at all,

then once its all adjusted up and fully working, periodically whilst at the petrol station, with the engine running and the hand brake off, press hard on the pedal a few times, just to re/adjust the hand brake mechanism,

of course if at some time in the cars life someone had retracted the caliper pistons by just forcing them back,
this will destroy the adjuster mechanism inside the caliper,

regards malcolm
curent ride
K reg BX 17TD TZD est
also own
K reg D special

no longer have
H reg CX saffari 2.5 TRI (now gone to Malaysia)
R reg xantia 1.9TD est (gone to meet its maker)
citronut
Over 2k
Posts: 2781
Joined: Wed Oct 31, 2007 7:55 am
Location: EAST SUSSEX UK
x 1

Re: Front caliper query

Post by citronut »

ps.

here is price and part No. for the caliper internal component overhaul kit

Part Number Description Quantity Price excl. VAT Price incl. VAT Total incl. VAT Selection
95590796 HANDBRAKE KIT 45.15 GBP 54.18 GBP 54.18 GBP

it does show the springs, which are a series of conical/dished spring steel washers,
which when fitted alternated face's together create the spring

regards malcolm
curent ride
K reg BX 17TD TZD est
also own
K reg D special

no longer have
H reg CX saffari 2.5 TRI (now gone to Malaysia)
R reg xantia 1.9TD est (gone to meet its maker)
Brian
BXpert
Posts: 441
Joined: Sun Jan 08, 2006 5:53 pm
Location: Bedfordshire UK

Re: Front caliper query

Post by Brian »

Right, I could not find the original picture, so I took another two.

Hope this helps any one who has not completely dismantled a calliper before.

Take care when removing the very strong circlip, "eye protection ".

Also make sure the "Dished Spring Discs" are assembled correctly.

Image

Image
Visa 17D 1986 192K Sorn
BX 17RD 1986 220K Scrapped 2013 - Too much rust.
BX 17TZD 1992 192K
306 XRDT 1996 175K
Defender110
Over 2k
Posts: 5917
Joined: Wed Dec 16, 2009 8:02 pm
Location: Harwood, Bolton
My Cars: Land Rover Discovery Series 1 200tdi 3 door
Land Rover Discovery Series 2 Facelift TD5
2020 Fiat Panda cross 4x4 twin air.
x 27

Re: Front caliper query

Post by Defender110 »

At that price you would just buy a recon caliper

Good pictures Brian thanks.
Kevan
1997 Mercedes C230 W202
2003 Land Rover Discovery Series 2 Facelift TD5 - Daily driver / hobby days and camping.
1993 Land Rover Discovery 200tdi Series 1 3 door - in need of TLC
2020 Fiat Panda 4x4 Cross Twin Air.
User avatar
cauchoiskev
BXpert
Posts: 282
Joined: Mon Aug 15, 2005 11:36 am
Location: France

Re: Front caliper query

Post by cauchoiskev »

Yes, fantastic pictures, thanks. The spring looks sturdy enough, surely it must be broken by abuse rather than wear ?
KevR
1K Away
Posts: 1767
Joined: Mon Apr 12, 2010 8:46 pm
Location: Normandy
My Cars: It's all in my signature
x 4

Re: Front caliper query

Post by KevR »

I've got a couple of those recon kits (95590796) which I found NOS a while back, and although they have the dished spring washers, they don't seem to have the thrust (ball bearing) washer or the spring that's shown in Brian's photo....
1990 BX TZD Estate ('the grey one', 1991 BX TZD Estate ('the white one'), 1982 2CV6 Charleston (in bits), 1972 AZU Serie B (2CV van), 1974 HY72 Camper, 1990 Land Rover 110 diesel LWB, 1957 Mobylette AV76, 1992 Ducati 400SS, 1966 VW Beetle, 1990 Mazda MX-5, 1996 Peugeot 106D, 1974 JCB 2D MkII, 1997 BMW R1100RS, 1987 Suzuki GSX-R1100, 1978 Honda CX500A, 1965 Motobecane Cady, 1988 Honda Bros/Africa Twin, 1963 Massey Ferguson 825, and a lot of bicycles!
Post Reply