Front Brake Pad And Disc Replacement

[PICASSOCONVERT]

Well here goes - the sequel to my posts on rear pad/disc replacment and corrosion removal. First of all I did my homework - read the pinned post on this topic and pages 126/127 of the RTA manual.

 

Got the car (2003 2.2HDi estate, 90,000 miles) raised up and propped and the front offside wheel off. The only additional precaution I took to the pinned note instruction was to chock the rear wheels as the car was going to be in neutral with the handbrake off. Also applied some steering lock to get a better view.

 

First step for me (as a novice) is to have a long, hard look at what I can see and ensure that I understand what I am looking at. At this point I realised that the pinned note wasn't for me. My car doesn't have a pin securing the bottom of the caliper.

 

So, after a re-check with the RTA manual I could see that I had what was shown in their pictures - a caliper secured by two bolts (new ones are supplied with the new pads). After removing the handbrake cable and the pad wear sensor wires (noting the route they take as per pinned post) I removed the two bolts and with a bit of gentle tapping using a hammer and a bit of wood the caliper came free and I could remove the pads.

 

At this point it is worth noting that my car has only one piston in the caliper - on the inboard side, with the outer pad fixed up against the caliper. It appears that the whole caliper can move sideways on its mounting bolts (hence the rubber gaiters near the mounting bolts) to keep everything centred on the disc as the pads wear.

 

The pads came out easily and the thickness left in them was 8.5mm total (new pads 11.5mm) with approximately 6mm to go until the wear indicator would touch the disc. So, about 1/3 worn. Surprising to me, as the car has not had new pads since I bought it 38,000 miles ago. I do drive fairly gently (I know what's good for my wallet), but not to the extent of dragging my feet on the floor to stop!

 

The next step was to look at disc removal. Two problems here.

 

Firstly, unlike the rear dics, this one won't budge even with blows from a hammer (onto a wooden block to protect the disc). WD40 currently doing its stuff.

 

Secondly, I cannot see that it will be possible to remove the disc without first removing the caliper support, although the RTA manual does not mention specifically that this has to be done.

 

Additionally, the bolts securing the caliper support have (to me) funny heads. It looks as if they are similar to cap head bolts, but with splines inside instead of a hexagon. A quick Google leads me to think that they are male torx heads. As I don't yet have these in such a large size in my tool set I will have to acquire some. However, if someone could kindly confirm these are the correct things to buy I can get a set and carry on with the job in due course.

 

However, as the existing pads seem to have life left in them and the discs are also in reasonable condition (quite smooth and not scored) I may well just clean and re-assemble everything for the time being.

 

Not that I'm a coward or anything, just no point in doing jobs that don't need doing is there........................??

 

David

[Johndouglas]

Yes - the tool you need is a Torx socket.   From memory I think it's a T55 that you need.   Look on ebay and you'll find sets of six or so for around a tenner.

[paul.h]

Just had a look at the pinned post and it needs revising.

 

It may be your pads and discs were replaced before you bought the car and hence they do not need doing yet.

 

The Haynes manual says to remove the caliper bracket to remove the disc. A member put some pages from his Haynes manual here https://picasaweb.google.com/117321021404803473044/HaynesCitroenC5OnlineCarWorkShopManual# and will help until you get your copy.

 

If the disc is still stuck after the wd40 soaking, and a hammer still will not knock it off, even with a bit of heat, in the past I have used an angle grinder on the bit over the hub on other cars. Cutting a slot has been enough to release the grip on the rust.

 

If you decide to leave the disc until later, remember to use brake cleaner or other solvent to remove the wd40. When re-using old pads, rubbing the friction face on emery paper on a flat surface will remove the glazing and similarly on the disc. If you have wound the piston back, it should be adjusted so 1 mm max gap to the pads (I can not remember where I got this from but I have noted it in my Haynes) with a piston slot lined up to the mark on the caliper opposite the caliper slot. Once you have fit the pads, pump the brake pedal to move the piston and adjust the brakes before fitting the handbrake cable back.

[PICASSOCONVERT]

Thanks again paul.h for the words of wisdom and Johndouglas for the Torx info.

 

I did clean everything up with brake cleaner when I put the bits back together. As I was re-fitting all the old parts everything went back into place without me having to adjust the piston, but I have made a note of your comment about the 1mm gap and the marks on the caliper for future reference.

 

I am going to strip down and examine the nearside tomorrow morning and if that's OK I will put my discs and pads into storage for future use.

 

Finally, is it possible that the pinned post is correct for a different model to mine - perhaps the Mk2 or Mk3? The text does seem very specific about the pin which retains the bottom of the caliper.

 

David

[paul.h]

No, the pin mentioned was a mistake. The mark 1 and 2 brakes are the same and the mark 3 has a long spring holding the caliper to the bracket as well as the retaining bolts but these appear to use an allen key. Now I am a moderator though I can edit the post so it is correct.

[Johndouglas]

 The text does seem very specific about the pin which retains the bottom of the caliper.

 

KFK admits at the bottom of his pinned post that it's copied from the 'net and I guess it wasn't specifically about the C5 - although he does mention winding back in C5 fashion.   The pin and it's R retaining clip is misleading and as far as C5's go, shouldn't be there , however some front calipers do use such an arrangement, my Pug 306 has them for one.

[paul.h]

I have just done a temporary edit on the procedure and will finish it later - if there are any comments please feel free.