rear hydraulic pipe failure - where next?

[tim]

The BX Killer strikes! a rear pipe has popped just forward of the rear wheel. (Andy reckoned this was the main cause of BX Death as the cost of having a garage repair this would exceed the cost of the car....) Never mind, we is not afraid. The pipe went because I was pumping the brakes hard after doing some caliper work; if it hadn't it would have gone next time as it was corroded to nothing and split open....
So far; option a) is to remove subframe completely giving me full access to pipework. This has been suggested as the right way to go. b) replace the one offending pipe without touching the rest, meaning perhaps that the subframe doesn't have to come off. Apparently this is also doable, though I am again told that if I get it wrong and the new pipe touches anything it will soon fail from chafing, and the idea of dropping the frame is to make sure all pipes are properly clipped in and separated from each other.
So what d'yer think? To get the rear up I have a length of scaffold pole which I can run through the large holes in the rear towing mount plates, and with axle stands under them to give me height enough to work. But what about the front?? It will be depressurised and I have to get underneath to undo the pipe unions to fit the new pipe. I can either put jacks under the front ( which sounds a bit scary - I really want two wheels firmly on the ground) or I could perhaps run the nose a wee bit up some standard size ramps so that even when it's down I will still have room to crawl under. What do you guys do??
Also, looking at the thread below there is reference to dropping the frame on one side only which is enough to give you access.
It's been said before that you should replace all four pipes cos if one goes the others won't be far behind. Good practice I suppose but extra work? And if the others are all OK and still have the black coating then should this be an issue?
We just stripped out the scrappy subframe for practice and on one pipe there's what looks like bolt-on bridging piece fitted. Is this a quick fix for a busted pipe? Never seen one before. Are they any use?
And while I'm in there I shall do both rear arm bearings, new rear tyres, etc...

[mat_fenwick]

The other thing to consider about replacing all 4 pipes is that if corrosion has started under the black coating, it'll likely be where the clips are. So disturbing the clips may well hasten other pipes on their way - I'd do all of them if you're planning to keep it long term. Rear arm bearings aren't going to be much easier with the subframe lowered, so unless you have doubts why change them. It would be easy to check their condition with no suspension pressure though.

You could just splice in a new section, but a month or so back I couldn't find an affordable source for the flaring tool you can use on the car, only the one for bench use. And if you're taking the pipe off...

I'd put the front on normal ramps I think, or those giant ones if you can lift the back to match! As I've said before, I'm planning to do the job this year (before I have a failure hopefully!) so have been finding out what it entails. I might write up a guide for the FAQ section if I stay in a reasonable mood throughout. But it wouldn't be for a few months at least.

[Mickey taker]

Im no mechanic but it appears there are a lot of cars suffering from split or chaffed pipes lately.
obviously this is to be expected with age and muck build up from road salt etc.
I just wondered if it would be worth sleeving new pipes somehow before fitting to aid there longevity ?
I dont know if a rubber or plastic sleeve would help but it just seems a logical thing to do for long term protection.
Also the clips that hold the pipes seem to cause damage to the pipes long term, any thoughts on how they could be modified to reduce damage ?
Maybe it needs a smaller version of the things girlies use to keep there toes apart when painting there nails

[Dollywobbler]

Pipes age. Citroens have always suffered from this. Mk1 BXs were terrible, Mk2s had coated pipes so they lasted a bit longer. The Green Tiger had a front-to-rear repipe before I took it on. Apparently my TZD hasn't. (has now been identified as the suspension feed pipe).

[Vanny]

I dont know if a rubber or plastic sleeve would help but it just seems a logical thing to do for long term protection.

A sleeve will simply trap moisture, as can usually be seen on genuine pipes of a certain age. You'd have to coat/bond them while totally dry (ideally under a vacuum).

Cupro-nickel doesn't rot anywhere near as fast as the original Citroen pipes, and should really outlive the life of most BXs if not there owners. I've had a single cupronickel line on my car for over 5 years, and it still looks like new.

Mat, i can't find a 'hand' flaring tool either and Pleiades simply aren't interested in making up another batch. There tool doesn't make the best flanges and could be significantly improved, perhaps one for some Chinese rapid production outfit?

[tim]

I'm doing the rear arm bearings because they are truly stuffed. Frankly, even if they weren't I would still take the opportunity to dismantle them and inspect the races if I didn't know the condition.
I think I can only get the back up to the height of the jacks available and they are solid but ordinary - there may well be super-high jacks around but I ain't got them and don't know anyone with them. The mega-ramps would be nice to use but they are about five feet long and I haven't got room for them plus a car with actually blocking the garage door! Bum. I'll try with the smaller ones. If the back is angled down too much I'll have access problems at the back.
So... what about the subframe? General view so far is that I must replace all four pipes. I've heard the phrase 'lowering' the subframe several times - what does this mean exactly? As opposed to 'removing'. Do you undo all the bolts most of the way so the frame is still held in position but has dropped down a bit?
And the cupro-nickel sounds cool but where can I get some pipes made up in it? Flaring tool kits seem ridiculously expensive for what they are and I haven't got one.

[mat_fenwick]

And the cupro-nickel sounds cool but where can I get some pipes made up in it?

I spoke to Pleiades (01487 831239) a couple of weeks ago and it was something like £17 a pipe, cut and flared to the right length. Dunno whether that was plus VAT or not, as I repaired the pipe that went (fortunately just the operation return from the rear HC so low pressure). I also made the suggestion that they really should get themselves a website...

I think the issue with the clips is not that they damage the pipes, but that they create a mud/water trap so the coating fails sooner at that point. I will replace all of them, just couldn't stretch to either the time or cash required at the time.

[tim]

Point taken about the clips. In fact the pipe on the White One has gone just before it turns the final corner and well clear of the clip, so you can clearly see the whole plot. When we did the scrappy pipes yesterday, the clip on the subframe was absolutely rotted out so was probably doing more harm than good.
The only snag is the cost - I think that once the work is in hand and I can inspect the pipes more closely I'll decide on replacement on a pipe by pipe basis. I just thought of another snag - the pipes are about four feet long! Can they be coiled up for postage?

[Way2go]

I've heard the phrase 'lowering' the subframe several times - what does this mean exactly? As opposed to 'removing'. Do you undo all the bolts most of the way so the frame is still held in position but has dropped down a bit?

If the car is on axle stands under the rear sill jacking points, the rearmost subframe bolts (accessed in the boot) can be removed while supporting the rear of the subframe on a trolley jack. Lowering the the trolley jack will allow the subframe to "hinge" downwards to gain "operating space" at the front where the pipes cross the rear subframe. Using the axle stands (on high) in this way means the wheels can be removed giving plenty of access. It's also a good idea to support under the front too to give working space and pipe "wriggling" room here too.

If you only hinge the subframe enough to feed the pipes through then it's possible to just replace the offending pipes without straining the others too much. Check though as you go for anything else that needs to be disconnected if undue strain is likely to occur, its a while since I did mine and I may not have remembered all.

[tim]

Sorry, being a bit dense here..... if the remaining bolts are not released how can the unit 'hinge' downwards - and even if they were slackened off wouldn't the unit simply move downwards rather than pivot?

[citronut]

the only prob i can see with hinging the rear of the sub frame is you will likely tear the rear sub frame front bush's, as they are a round bush bit like the lower engine stabilizer bush,
so lowering the back of the rear sub frame will twist the rubber round in its self,

also i find if the rear s/f does not go up with all 6 mounting bolts square to the under side of the car, they get jammed and you then have to fight them to try and line up to locate them,

and yes cupro-nickel pipes can be coiled up for postage

regards malcolm

[citsncycles]

On Tim's estate we were changing all the pipes, so I dropped the subframe. To do this I had the rear edges of the sills on axle stands, the LH rear wheel removed and a scissor jack under each side of the subframe supporting it as it was lowered and raised. His was in particularly good condition with all the nuts etc. Free, so this was maybe a couple hours work.

Because of space etc. I ended up working on one end of the car at a time, but I'd definately look at putting the front wheels on ramps and then jacking the rear up in future.

[citronut]

i dont like standing cars on there sill edge's unless theres no other option ,

the scafild tube through the rear tow eye's i suggested to Tim and use this method all the time if and when dropping the rear sub frame,

but you do need quite tall axle stands,

regards malcolm

[Mothman]

As you said to me yesterday, the old motor is 'priceless' and if you need any help just ask. Glad too we sorted the scaffold pole.
Reccon it would be a good idea to get the front up on the small ramps but if you need your tractor jobbies, ile happily bring them round although moving them yesterday hasnt helped my back.
As i keep saying, cars, i kin hate em!!

Andy

[tim]

Well, thanks for all that, chaps. At the moment the way to go would seem to be 1) get the front up on the small ramps so I've got good access to the front unions (hope the old moo pumps up again, there's an awful lot of blood on the concrete), 2) insert Andy's scaffold pole through the back and support with jacks, which are 22" on the last pin. Wheels off, then rear arms (which were a priority and were going to be done anyway in the next couple of weeks) then detach the subframe. No scissor jacks but I've got a trolley jack and a couple of sets of pin jacks to support the subframe (which is not that heavy to handle). I'll then play it by ear as we go. I would quite like to look at the subframe mounts while I'm there anyway, for obvious reasons, and do a full visual on the pipes.
Anyyone disagree with the plan or have useful ideas? We'll take piccies so hopefully the end result will be useful. I could certainly use jacks under the sills but I'm just a teensie bit uncertain about having the full weight of the car transmitted through those rather ancient sills and Malcolm's idea does sound neat,