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5th gen brake pipe union size

Posted: Fri Jun 25, 2021 9:42 am
by Scott560
Hi All,

In preparation for the track day at the end of next month (Bedford full circuit), I'm planning to replace the flexible brake pipes with new/braided lines already purchased.

However, I have a strong anticipation that the existing unions will not undo easily. As a great planner of trying to fix things rather than make them worse - I came across a suitable looking tool that might assist, but I'm not sure what size the existing union is.

https://www.ebay.co.uk/itm/324506399162
https://www.ebay.co.uk/itm/324667945144

A couple of these look like the best way to deal with a stubborn union. If they cant do it, then nothing would? Obviously plus gas and the like will be used before hand to help persuade it.

Any advice greatly appreciated.

Cheers,

Scott

5th gen brake pipe union size

Posted: Fri Jun 25, 2021 12:26 pm
by Vtecmec
The way that works for me best is to cover the union in Bilt Hamber detox gel the day before, which removes any of the corrosion.

This both frees them up and leaves it all in a condition that can be painted in hammerite after you've done so they remain in good condition.

This method has worked for me when all else has failed.

5th gen brake pipe union size

Posted: Fri Jun 25, 2021 3:19 pm
by Scott560
I've ordered a bottle of that and the spanners (got both sizes, for the sake of 9quid I'm sure it will come in useful at some point). here's hoping that between the hard lines, master cylinder rebuild and a pressure bleed and some new track pads i can finally get some better feel in the pedal!

5th gen brake pipe union size

Posted: Fri Jun 25, 2021 4:01 pm
by Vtecmec
From memory, I think the unions are an 11mm spanner.

With the gel, slap it on and around the union and pipe, work it around a little with a toothbrush or small wire brush, then wrap it in clingfilm to stop it drying out.

If it has dried out the next day, adding a little more gel for 5 mins will soften it up so you can get it off.

I redid all what your doing on mine early last year, its quite surprising how effective the standard brakes are when fully fit!

5th gen brake pipe union size

Posted: Fri Jun 25, 2021 7:58 pm
by Scott560
Yeah i think the MC rebuild is going to have the biggest effect.

The only problem i'll have is i'm replacing so many parts at once, i won't know what each change brought in isolation. I'm guessing the MC is the main culprit of my poor pedal feel (on road pads), because just occasionally i will get a really firm pedal. Gone for PBS pads this time. Nothing wrong with the ds2500 on ATR drilled discs, but the pads had started to crumble so they were probably a little unhappy at 10lap stints...

good news is amayama have shipped the pistons/seals for the cylinder so i know they are on their way, and i can rebuild my spare MC. Looking forward to using the pressure bleeder aswell.

5th gen brake pipe union size

Posted: Sun Jul 25, 2021 10:12 pm
by Scott560
Managed to get my MTEC braided lines fitted in the end (with new retaining clips and sealing washers ordered separately). Since the car is on stands and wheels removed already, I was able to use a couple of different penetrating fluids over the course of a couple of days. Didn't use the deox gel in the end, they were covered in so much grime that underneath it all they were quite OK.

The flexible part of the old brake pipes, no nut on them, had to use vice grips to stop them twirling whilst undoing the nuts.

10mm is the size of the hard brake pipe union nut. Absolutely no way they could be removed without the special tool linked above. The breaking torque required was pretty high, no way a 10mm spanner could do it, and I wouldn't hold out too much hope for a flare wrench either. Very impressed with the tool. Cumbersome to use, but you only have to crack the nut open 1/4 turn and go back and forth, then it frees up enough for normal spanner to be used.

The rears, the flexible brake pipe is held onto a bracket - it was easier to remove the bracket (2x 12mm bolts), and then attack the bracket to pipe bolt with an impact when it was in the vice.

A fiddly job but all done in the end.

5th gen brake pipe union size

Posted: Mon Jul 26, 2021 9:48 am
by Drax
oooo those spanners look useful and the Bilt Hamber detox - i shall order some myself cheers lads 8)