Failed "MOT" - rear brakes

[elma]

My method was to wire brush the protruding bolt ends then undo them with a 240v impact wrench. Mine were tight so I blowtorched a bit around the bolt ends.
I'm reluctant to use a bar on them nowadays as I've snapped a bolt on a Xantia rear caliper in the past. If I did I think 150cm sounds adequate.

[darbuck]

i agree with elma too much leverage may cause too much shear and literally tear the head off or snap the bolt.as as i said earlier take your time and loads of lubrication accompanied by steady force dont be tempted to shunt it as you'll almost certainly snap something.

[dnsey]

That's the advantage of a long bar, IHMO.
If you dont have to use all your strength to pull on the bar, it's easier to feel what the bolt's doing and avoid shearing it.

[Ben82]

Thanks guys, I went shopping today:


breaker bar, rubber weighted mallet, wire brush, caliper file, caliper grease, copper grease, brake cleaner, and a torque wrench.

Also had the wheels off today, used the WD40 on the bolts a couple of times, and used the wire brush to clean them up too Will be trying to do that every day now up until next sunday, when we will be doing the work

[darbuck]

hmmm shiny not for long nothing better than breaking in new tools.

[Xantidote]

Not sure if it's been mentioned earlier, but assuming the caliper bolts fit into a threaded section on the trailing arm similar to on the Xantia, can I suggest that in addition to applying your penetrating oil to the bolt heads, that you also "grope round the back" and give a good dose to the threaded end of the bolts, which may or may not project through their fixing on the trailing arm.

Good luck when you finally start the job.

[Ben82]

Not sure if it's been mentioned earlier, but assuming the caliper bolts fit into a threaded section on the trailing arm similar to on the Xantia, can I suggest that in addition to applying your penetrating oil to the bolt heads, that you also "grope round the back" and give a good dose to the threaded end of the bolts, which may or may not project through their fixing on the trailing arm.

Good luck when you finally start the job.

Yup I did that too I will probably increase the dosage of wd40 as the week goes on too.

[Ben82]

Didn't have time to get around to doing the daily squirting today. Was driving around in a mk2 C5 until about 6pm and after that it was too late, and I was too knackered from moving stuff around today. Will most likely do that tomorrow morning, before going back into the city to get the parts from the citroen dealer, along with the correct bit to go on the breaker bar and hopefully fetch something to use as an extender to the breaker bar. The move has been going so well, the actual work with changing the brake pads and discs etc might get pushed forward to Saturday, Saturday does look a better day weather wise too).

[Ben82]

Another shop done today

Got the cheater bar from the place Steve suggested - thanks Steve Car in pic for scale lol

Also realised I needed a 3/4" to 1/2" downsizing bit for the 16mm bit, and was looking at a 1/2" 16mm bit in the shop, but thought I'd have one at home... turns out it's a 3/8"s one. So will have to go shopping again I think. As 3/4" -> 1/2" -> 3/8" probably isn't a good idea for such a long bar use. (and I'm not really confident of the quality of the 1/2" -> 3/8" downsizer bit).

I also picked up all the bits from Citroen today for the job. Also decided to get new metal shield bits (can't remember what they're called), but the new ones are shiny and are actually branded... maybe the old ones are too but have rusted over.

Also had a chat to the guy there about the job. He was saying about it can be quite a difficult job etc. Didn't get the impression he was touting for my business, but more just wanted to advise me and wish me luck etc. He did think that they might not be too bad since the car has only done 147000km, but can be damn near impossible if they've done over 250000km.

Pads and Discs also arrived today, the discs are way more heavier than I thought they'd be.

I'm also pretty sure I can see the issue too, the passenger side disc does look far worse for wear than the driver's side one, even after using brake cleaner on both, the driver's side one still seems to have some shine to it. The passenger side one doesn't appear to. I think the corrosion has started to score the disc on that side too and I can see a bit of the corrosion from the top which lines up with one of the score marks on the disk.

EDIT: Yes the car is wearing both alloys and steel rims. I swapped the rear tyres back to summer tyres the other day since I already had the tyres of... couldn't be bothered to switch the front yet. Technically the fronts are all weather tyres, maybe I'll switch them over soon

[Ben82]

The bottom bolt sheared, even though we were going easy on it. The top bolt appears to be coming though fine... Is there anything we can do with it? or will we need a new caliper?

It sheared about 1cm from caliper end. Any advice on what we can do? we are persisting with the top bolt to get the experience for the other side, which hopefully will be easier. (less corrosion all round).

[elma]

The bolt goes through the caliper and into the rear arm. It sounds like you've been fairly lucky where it broke as you'll have plenty to grip when the caliper off. Once the other bolts out the caliper will just lift off over the shaft of the broken bolt. Well i say just lift but they are likely corroded together and in need of coaxing. You shouldn't find it terribly difficult to get the bolt out with mole grips or similar once the caliper off. I doubt you'll need a new caliper, just new bolts and a tap, m9 if I remember right.

[Ben82]

thanks elma, We're having a bit of a problem with the other bolt too.. it seems to just be turning on the spot now (it's quite far out), but still needing leverage to turn (and it creaks like anything).
Our other issue seems to be the brake hose is solid rather than flexible (maybe normal!) so didn't think it'd move too much once the caliper is loose.

Some pics:
How far out the top bolt is: http://puu.sh/jCAqm/a240d21b90.jpg" onclick="window.open(this.href);return false;
The sheared bolt hole: http://puu.sh/jCArj/393f8c914a.jpg" onclick="window.open(this.href);return false;
The sheared bolt: http://puu.sh/jCAsg/bbb7b75022.jpg" onclick="window.open(this.href);return false;

[Hell Razor5543]

Ouch. If you can get them, an Aston Super Wrench should get that out (once you have got the calliper off), as they grip securely, even on a solid bar.

[elma]

The second bolt is probably undone so not unscrewing towards you any more. I'd preferably pull it out with a slide hammer. Failing that get some old pliers under the head and hammer them to pull it off. It's stuck on threadlock and corrosion so will resist.

The pipe should be solid, it needs to be undone to remove the caliper.

[Ben82]

Thanks again elma,. When removing the brake pipe how do you stop it from leaking brake fluid? Or does it have a stop when undoing it?