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Rounded off brake line

Posted: Sat Jul 02, 2016 3:59 pm
by unknownmale
Doing the rear brakes on a friends car as they failed the MOT...It's been a nightmare, so much rusted out.

Looks like someone has attempted to do the drums a while back but rounded off the two 5mm allen bolts holding the slave cylinder on. So I thought I'd just undo the brake line, take off the axel and backing plate, drill the rounded bolts off etc.

Only the brake line nut is also rounded off + years of rust. Looks like my only option now is the cut the brake line and put in a compression fitting.

I've just bought a kit to make flares, but i'm not sure if this is an MOT failure? I've read differing opinions.

Also, to the rear drums is it just one line from the master cylinder all the way back, or is there a join somewhere in between?

I know it would be best to run a full line, but i'm really not up for that.

Cheers

Re: Rounded off brake line

Posted: Sat Jul 02, 2016 6:07 pm
by james butler
only rusty or insure pipework and ferules will fail the mot.
ideally replace the whole lot but there is nothing stopping you just jointing a new piece in as long as its secure.
one line to the rear is not uncommon on old cars as my datsun has one line to the rear which t pieces to either side ( it is important it is piped correctly through a brake bias regulator if it has one)
i would always recommend popping down an MOT station and asking for their opinion before starting work as then you will KNOW the correct answer to your question and how much work you will have to do.

Re: Rounded off brake line

Posted: Sat Jul 02, 2016 8:10 pm
by unknownmale
Thanks mate. Good to know.

Never made up a brake line before, bit nervous being as it's a mates car.

Re: Rounded off brake line

Posted: Sat Jul 02, 2016 9:36 pm
by james butler
just make sure you follow the instructions with the flare kit and make sure you put the ferrule nut on first before you flare the pipe otherwise its not going on (done that a few times!).
make sure once you`ve finished doing the job one of you presses hard on the pedal and the other check for leaks!!

Re: Rounded off brake line

Posted: Sun Jul 03, 2016 1:20 pm
by Nate
Be warned, quite a lot of the cheaper flare kits don't like flaring steel pipe. I think you'd be better off just replacing the whole pipe all the way back to the flexi rather than messing about trying to flare it. If you don't get the flare in the steel right and it leaks, you'll probably end up doing that anyway.

For doing brake lines, the other sensible tool purchase is some proper flare nut spanners (sometimes called crow foot spanners) these are basically a 6 sided ring spanner with a little cut so you can slip it over the pipe. You can also buy them to fit a ratchet handle, so you can use them on an extension to get into awkward places. These are useful for the front to rear brake line where it meets the flexi hose.

Normal open ended spanners don't grip the nuts anywhere near as tight and are much more likely to round off the nut.

Re: Rounded off brake line

Posted: Sun Jul 03, 2016 5:39 pm
by unknownmale
Thanks Nate, Yeah, I always use flare nut spanners with brakes, the nut is round and corroded unfortunately.

Re: Rounded off brake line

Posted: Sun Jul 03, 2016 6:42 pm
by Nate
Cold chisel to take the pipe off right next to the nut and get a 6 sided socket on it to remove. Had to so that to mine at mot time as the nut wouldn't come through the back plate

Re: Rounded off brake line

Posted: Sun Jul 03, 2016 10:36 pm
by james butler
get some plus gas on it the night before you do the work which will give it plenty o time to penetrate the rusty joints.

Re: Rounded off brake line

Posted: Sun Jul 03, 2016 10:42 pm
by unknownmale
I've actually got a new set of backing plates, so can salvage the old ones if I need them down the road.

I was just going to cut right next to the nut, deburr and flare it and work the line closer to the cylinder. Had another look at it today, I think there is enough line there to do it without bending it or adding more in.

The nut is completely rounded off, will try some vice grips on it as a last resort then cut the nut off if it comes loose.

The other idea I had was to remove the backing plate with the line still attached, drill out the allen bolts holding the cylinder on then grip the nut with vice grips and twist the cylinder.

Will have to face it next weekend, will post the results!

Re: Rounded off brake line

Posted: Sun Jul 03, 2016 10:44 pm
by unknownmale
james butler wrote:get some plus gas on it the night before you do the work which will give it plenty o time to penetrate the rusty joints.
Aye aye, smothered in an ATF + acetone mix today

Re: Rounded off brake line

Posted: Mon Jul 04, 2016 12:05 am
by Nate
If you've got a flare kit like this http://www.ebay.co.uk/itm/131675901576 then I really wouldn't recommend trying to flare the steel pipe with it. The dyes aren't very strong and are likely to break.

Re: Rounded off brake line

Posted: Mon Jul 04, 2016 10:05 am
by unknownmale
I don't have that style no, it's a hand grip style. I only paid £35 for it. I'm sure it's not as good as professional piece of kit

Re: Rounded off brake line

Posted: Sat Jul 09, 2016 7:27 pm
by unknownmale

Re: Rounded off brake line

Posted: Sat Jul 09, 2016 10:05 pm
by james butler
wow you wernt kidding about the rust!

Re: Rounded off brake line

Posted: Sat Jul 09, 2016 10:18 pm
by unknownmale
james butler wrote:wow you wernt kidding about the rust!
She's a scaly one alright! Noticed the hand brake leaver is further over like you mentioned yours was, handbrake is rubbish as well, going to throw some new cables on it...see what that does.