Sliding caliper repair kit question

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the_weaver
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Sliding caliper repair kit question

Post by the_weaver »

I've bought a sliding caliper repair kit, for the Bendix front brake caliper on my ZX 1.9D. It's a genuine Citroen kit, with the part number 443903. The kit has got two metal sliders, four rubber gaiters, and two 'O'-rings. My question is - where do the 'O'-rings go?

I think the 'O'-rings fit in the grooves in the holes in the caliper, and the metal sliders slide through the 'O'-rings. However, they've only given me one 'O'-ring per slider, and there are three grooves in the caliper body to choose from. Which groove am I supposed to fit the 'O'-ring into?

At first, I was going to fit the 'O'-ring in the middle groove. I was thinking that the function of the 'O'-ring might be to help "centre" the slider in the bore, so that you could bolt the caliper on easily, without spending ages trying to get it to slide without catching on the sides.

Then I thought, that maybe the function of the 'O'-ring is as a seal. If it's a seal, then it should go at one end of the bore, but why didn't they give me two 'O'-rings per slide?

The 'O'-ring is very good at taking the grease off the slider. If you grease a slider, and slide it through, most of the grease comes off, and nothing much goes into the caliper. Maybe that's why they only give you one. One end is tightly sealed by an 'O'-ring. The other end has no 'O'-ring, and is the "access point" from which you insert and remove the greased slider. It's also the access point for future greasing, if necessary. If this is correct, then which end do I put the 'O'-ring on?

The sliders have got two grooves, for the gaiters to locate into. One of the grooves is about 1mm from the end. The other groove is about 4mm from the end. The end with the 4mm gap has got a flattened bit, with another groove, which looks like it's designed for a Citroen tool (or pair of pliers) to pull the sliders out. It looks like the sliders are meant to be pulled out from the larger end. As this end is usually the one that goes rusty, it makes sense to do it that way, so that you're not pulling the lump of rust through the caliper body. I've seen a reconditioned caliper, which has the large end of the slider, on the side that goes towards the hub. Assuming it's correct, then that would mean that the sliders are pulled out towards the hub, and therefore the 'O'-ring must go on the other end, nearest to the stop plate.

If my theories are correct, then the sequence of components would be as follows:-

Bolt head --> Stop Plate --> Small 1mm end of slider --> 'O'-ring at Stop Plate end of caliper bore --> Caliper --> Large 4mm end of slider --> Hub

Does anybody know if this is correct?


The Peugeot kits, 443905, don't seem to have the 'O'-rings. The sliders look similar, but the plating seems to be heavier (chrome?). The slider, on the one kit I've seen, seemed to be a slightly tighter fit in the bore, and measured slightly bigger on a digital caliper. I know I've only seen one example, but I'm wondering whether Peugeot specified heavy chrome plate, to prevent the rusting that occurs, and left out the 'O'-ring to compensate for the heavier plating. Or, maybe they left out the 'O'-ring because it was a pain, and didn't work properly.



Paul
ZX 1.9D, 1993, 218K.
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Re: Sliding caliper repair kit question

Post by citronut »

the kit on service citroen part No. 4439.03 does not show a seperate O ring, unless it is ready fitted into the groove at the longer end of the slider,

also in the drawing the longer end of the slider is pointting the same direction as the calliper piston, even though the drawing for the slider kit is shown in a seperate box above the calliper drawing,

regards malcolm
the_weaver
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Re: Sliding caliper repair kit question

Post by the_weaver »

Malcolm

You're right about the drawing on service.citroen, but have a look at the picture of a ZX Bendix caliper in the link below, from aepdirect. It looks like the longer end of the slider is nearest to the hub in the picture. You can zoom in for a bigger view:-

http://www.aepdirect.com/front-brake-ca ... ory_id=793" onclick="window.open(this.href);return false;

I wonder if the 'O'-rings are supplied with older Bendix kits, but the newer Bosch kits don't have them.


EDIT: I just realised that the picture on aepdirect is a bit confusing. It's labeled as "right hand caliper" but it actually shows two different calipers, one is the right hand caliper, the other is the left hand caliper.

The caliper picture I was referring to, is the one in the upper right of the picture on aepdirect. That is a right hand, offside, driver's side caliper. If you imagine turning that caliper over, and bolting it to an offside hub, then the longer end of the slider would be nearest to the hub. As a confirmation, the bleed nipple would be uppermost, showing it's the correct caliper, as the air rises to the top.



Paul
ZX 1.9D, 1993, 218K.
citronut
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x 92

Re: Sliding caliper repair kit question

Post by citronut »

that is as service citroen show it the longer end pointing the same direction as the piston/towards the brake disc,

regards malcolm
the_weaver
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Re: Sliding caliper repair kit question

Post by the_weaver »

Malcolm

That's ok then. It's in agreement.

The drawing on service.citroen is confusing because it shows a nearside caliper, and the caliper mounting bolt (item 4) is pointing in the wrong direction. The way it's drawn, it looks like the bolt head is on the other side of the caliper to the stop plate.

Paul
ZX 1.9D, 1993, 218K.
citronut
Posts: 10937
Joined: 29 Apr 2005, 00:46
Location: United Kingdom east sussex
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x 92

Re: Sliding caliper repair kit question

Post by citronut »

yes i agree it does show the bolt heading ass about face, very missleading,

regards malcolm
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