Failed "MOT" - rear brakes

[elma]

It'll drip. I'm not sure if you can depressurise a c5s brakes, they're normal. I'd just tape a plastic bottle to the pipe end after releasing it. Best await more informed advice though, i know little about the systems on modern cars. Be careful with the pipe, unclip it where you can for movement, use a perfect fitting spanner and don't stress the pipe. Probably worth mentioning the little pipe seal that'll want replacing, I think it's 3.5mm but can't remember so haven't put a link.

[lexi]

I usually taper a beechwood dowel or plastic knitting needle to fit in the pipes and plug the orifice to save mess and fluid loss.
The bolts breaking are one of the reasons I have welding machines. A nut welded over a broken stud always comes out. The heat in welding, transfers down the stud and breaks the thread's grip. I am thinking you have nobody with a welder around, so vice grips it may be.

WD 40 is poor as a release agent Ben.

[Ben82]

The wd40 was the one Steve mentioned a few pages back: http://www.frenchcarforum.co.uk/forum/v ... 94#p457346" onclick="window.open(this.href);return false;
So isn't the regular wd40. But my options were fairly limited between unknown brands and essentially our "halfords" own. I've used it liberally over the past few days.

Yup know no-one with a welder. Will have to see if we can get some vice grips tomorrow.

I am hoping the other side is less corroded so if we manage to get the caliper off on this side we can do the otherside without too much of an issue.

There is a garage around the corner too that I wonder might be able to help on Monday, if we don't make any progress tomorrow.

[elma]

You should be able to manage it Ben, you're having the same problems I had the second time I changed Xantia brakes. My Stud snapped down in the thread though so had to be drilled out and retapped. If you've a hot air gun or small blowtorch that will help release the bolts, like the heat Lexi gets from the welder. Be careful if you use a blowtorch and put a heatproof mat over the pipe and abs sensor. Heat works wonders with old thread lock and it would be worth using on the other side even if it looks less corroded.

If you feel like doing anything like this again in the future I'd really suggest one of these and a small blowtorch. I've not had any snapped bolts yet using mine, except a Volvo locking wheel nut key. Be careful using your bar, it's easy to feel like the bolts unwinding when actually it's twisting towards snapping as you've probably noticed.

[myglaren]

I should have mentioned that when using the breaker bar it helps to oscillate it, that is move it anticlockwise (loosen) until you feel resistance then clockwise (tighten) repeatedly.
Helps to break the corrosion and threadlock seal without stressing the bolt until it shears.

[Ben82]

Brake line appears to be twisting as we're undoing the 11mm bolt, is this normal or are we doing it wrong?

[elma]

Looks like time to stop now Ben, maybe ask your garage on Monday. It shouldn't twist like that, looking at your picture the pipe doesn't look straight and the corrosion isn't helping matters. Sometimes you have to untwist the caliper rather than unscrew the fitting. As the stud is broken it gets a bit more difficult. The chances of having to replace a portion of the solid brake pipe are increasing considerably for you. I think it will now save you time and aggrivation to back off and seek help or you could end up with a split brake pipe which is no fun, even if you have the flaring tool.

[myglaren]

Pipe corroded fast into the threaded fitting - that's another place that drenching with release oil will help.

It is probably weakened now and will eventually fracture even if it comes out more or less whole.

I ended up replacing every pipe - brake and suspension - on my GS due to that. Lots of fun and the pipes cost more than I paid for the car.
It started with a brake disc (rear) that needed replacing.

You may be able to cut that pipe and put a repair piece in - likely a workshop job as it will need a flaring tool. Fortunately the C5 - I am reasonably certain - uses standard brake pipes rather than the previous dedicated Citroen ones.

Never simple is it Ben

[Ben82]

Nope my concern is the local garage here, I have no idea how well they know Citroen's. Part of me kinda is relieved that we found this ourselves though as the garage probably would have added on a bunch of time and parts. I have at least saved money on the discs and pads, though have spent some on tools etc. It may be worth me ordering in the calipers if they think they need replacing, but that would extend the amount of time I would be without a car. And less time for it to be sorted before the mot retest

[elma]

It's more the pipe thats a concern Ben. If you want to do it yourself it's not actually that hard but you will need to get hold of a flaring tool, a cutting tool, pipe, an end fitting and an inline fitting. I don't know the sizes for the C5, but someone will.

I wouldn't worry about a calliper yet if it's not leaking. Often the corrosion can be chiselled off and the calliper side sanded smooth. You are likely going to have to wait for the flaring tool etc though so it may be wise to order a calliper just in case.

Where are you up to now? Is the second bolt all the way out?

[Ben82]

On the other bolt front, we were hoping if we could get the brake hose off, we could hopefully get the caliper off, then get the bolt out by hammering it or so, however it just won't budge, you can turn it either way. We tried using a grip to try to pull whilst turning the bolt, but it just doesn't seem to want to move any further out. You can turn it either way with a torque wrench, but still not a spanner. I don't want to whack it forward with a hammer just in case the thread on the arm is corroded so wouldn't want to damage that. I have tried giving it a tap with the hammer from the sides though to no avail. Did buy something similar to the Aston super wrench today, but never got the caliper off to try it out on the sheared bolt.


Is it worth trying to do the brake hose back up again? Or would that potentially snap it?

[elma]

I think your options on the remaining bolt are:
1. Heat
2. Impact wrench
3. Hammering outwards
4. Heat combined with either of the other 2.

I'd focus on the bolt first as it's in the way of the next steps. If you're unscrewing it and it won't come outwards the threads are undone. It's the rot and thread lock between the calliper and the bolt stopping it moving. The rot is white stuff caused by galvanic corrosion rather than your traditional rust and hammering out should do no harm.

Once it's out you may as well just undo the fitting or cut the pipe accepting that it's worth replacing now and makes life easier. No harm doing it back up right now, but if it's not leaking I'd be inclined to leave it alone.

The calliper will need persuading off a bit, probably a decent tap with a soft hammer.

Then onto the broken stud, heat on the thread bit and your new grip should remove that relatively easily compared to with the calliper there.

The pipe repair should be a nice job for you after all of this, the flareing tool is quite satisfying to use.

The caliper shouldn't be terribly hard to clean up. If you can get that bolt out you'll be able to assess it yourself before ordering another.

[Ben82]

My concern with heat is my inexperience and being close to the fuel tank. If it was the driver's side then I could probably give it a try.

[elma]

Have a look at a pencil blowtorch, it's a very little precise flame. They can be used for soldering as well. I don't think it'll worry you to much especially if you get a heat proof mat to cover any bits you really want to avoid.

[Ben82]

Hi elma, thanks, we've been using other motors this afternoon (a lawnmower and a brush cutter) to get the garden at the new house in order so haven't touched the car any more since the photo earlier.

I am in two minds about it to be honest, fixing it myself will come with quite a bit of satisfaction of it finally being sorted. However my issue is going to be time, and getting more tools to do the job. I lose my potential taxi and second pair of hands/eyes tomorrow morning (as my parents go back to the UK) And the wife doesn't generally have the patience to help out with the car After that I'm back to work so won't be able to work on it until the weekend, and I think after the 3rd of September, it'll need a note or something from a garage to be able to be driven legally on the road (i.e. that the garage is fixing it or it's on it's way to be re-tested)

After dropping the daughter off at school tomorrow (a short walk away) I might pop down to the local mechanic (who's also walking/biking distance away) and see what he says for it. I think there's a bunch of stuff that's going to be needed new like the thing that goes from the brake line into the caliper. Would also prefer to buy new pad retaining springs too as this one looks like it'll snap just by looking at it. If the local mechanic can get the caliper off, the bolt out and the brake line repaired, I should hopefully be able to do the rest as it should be just putting everything back together. But of course then I need to be looking at doing the other side almost solo. Which to be honest, visibly doesn't look half as bad. (the disc is quite shiny in comparison etc, and there was no where near as much corrosion on it as there is on this one).