Technical Brake pipe nut sizes

[Yolanda]

Can someone tell me what size the brake pipe nuts on the rear wheel cylinders are as I want to buy a set of brake pipe spanners. I'm led to believe they could be 11 mm but some of the kits don't have that size. I'm away from home at the moment in my other car, so I can't measure them.

 

[koalar]

10mm flare nut spanner will do 90% of Fiat brake pipes
Buy a decent one
Cheap brands will only end up rounding the nut

 

[koalar]

Soak overnight even then it will Probably need some heat as well

If they are like this it takes patience

Spin too wildly you will just twist the pipe off

 

[bugsymike]

Most of my brake pipe spanners are dual ended 10mm and 11mm, if a choice, go for hexagon not bi hexagon as less chance of slipping/rounding off. I still have the ones for older British cars 7/16inch and 1/2 inch. If you have to have new metal brake my advice is to go for the Kunifer pipe (copper and nickel) it doesn't rust and is stronger than the cheap plain copper some garages use which is softer and more prone to sticking to the union so twists it's self off needing more new pipes.

 

[koalar]

Most of my brake pipe spanners are dual ended 10mm and 11mm, if a choice, go for hexagon not bi hexagon as less chance of slipping/rounding off. I still have the ones for older British cars 7/16inch and 1/2 inch. If you have to have new metal brake my advice is to go for the Kunifer pipe (copper and nickel) it doesn't rust and is stronger than the cheap plain copper some garages use which is softer and more prone to sticking to the union so twists it's self off needing more new pipes.

Correct

As far as I know a standard 10/11 mm brake flare spanner will do everything on a Panda I haven’t undone everything though

Some of these are rubbish

The Laser one fits the best. Could just be the luck of the draw.

The only other size ever needed is 12mm if you work on jap cars

 

[Yolanda]

Thanks for the quick reply's

 

[Yolanda]

I'll probably buy a good quality set, as the wife has a Corsa and I've got a Merc as well.

 

[bugsymike]

That should be ideal.
Now after 50 years, retired from Motortrade, I always made my own I will say a rewarding job (not always financially ) but never regretted it.

 

[koalar]

95% of all cars have a standard 3/16” brake pipe. Yes the pipe is still imperial yet the fittings are now metric

Hence one spanner fits all 10/11 mm. Depending on the brand of fitting. Sometimes when you change a pipe one side will be 10 and the other 11 because it already been changed by a garage and there fittings were different

Some Jap cars use a larger pipe on the ABS hence the need for a 12 mm

Never needed any other size recently and are the only metric ones I own

A Class
Corsa
Punto / Panda
Slash / Alto

My 12 mm was a online order from Halfords by the way. Rubbish, over size and a sloppy fit. Just happen to have in front of me and it measures 12.25 mm I nearly sent it back. It’s the only Halfords tool I have ever been disappointed with. Of course it could be just bad luck

They are all slightly over size but the better fit ones are 0.1mm or less doesn’t sound a lot of difference but you are much more likely to round off the fitting. It is noticeable in the amount of free wiggle

I have only two Laser spanner’s a 14 mm combo and a 10/11 mm brake flare both are good on size and finish, again could just be the luck of the draw as it’s only a sample size of two

Unless you are changing thermo couples or something similar I would just get a 10/11 mm and spend a little more on it than get a set. Add a 12mm if needed I had to order this online as most motor factors don’t carry stock which was annoying having to wait.

 

[rmjbn1]

I failed to free the nuts from the brake pipes after a good soak and a fair bit of heat. Was twisting the pipes.
So I ended up holding the nuts steady with a spanner and unscrewing the wheel cylinders off the pipe instead.
Hey-ho. It worked, no leaks. Just gave the nuts a final nip tight when everything was back together.

 

[bugsymike]

I have had to do that to get out of trouble in the past.

 

[DaveMcT]

The flare nuts on mine have metric threads, but my very old Britool 1/2 inch flare nut spanner fit perfectly.

The brake pipes are zinc plated steel** with a plastic sleeve over the lot. Over time, the zinc fluffs up and expands the plastic under the nuts. No amount of lubrication will shift them. To avoid twisting the pipe you have to warm the nut with a heat gun or gas lighter flame. Just enough to soften the plastic is good enough. You will them need to clean off the split plastic sheath and paint or otherwise protect the steel pipe. I use anti seize paste and years later its looking good. Obviously take great care to not get any inside the pipe as common grease will damage brake hoses and seals.

** I had thought the pipes were aluminium but they are magnetic so def steel.

 

[koalar]

The flare nuts on mine have metric threads, but my very old Britool 1/2 inch flare nut spanner fit perfectly

Are you sure
1/2” = 12.70 mm

 

[DaveMcT]

I bought a metric flare nut spanner, before doing the axle swap. It went back to the shop because my old imperial spanner fitted better.

 

[koalar]

The flare nuts on mine have metric threads, but my very old Britool 1/2 inch flare nut spanner fit perfectly.
.

I bought a metric flare nut spanner, before doing the axle swap. It went back to the shop because my old imperial spanner fitted better.

again 1/2 is far too big at 12.7mm to be of any use at all

Are you sure you don’t mean a 3/8 and 7/16 flare spanner as it’s a close equivalent to a 10/11mm

3/8 = 9.53mm
7/16 = 11.13mm

I often knock on 3/8 socket on a badly corroded or rounded 10 mm bolt however it normally takes some force. The heat shield bolts are a good example of where I use this approach. 3/8 does not fit or hammer on a 10mm bolt that is in reasonable condition

take a look at the photos I posted above. That pipe was undone with the proper tool for the job a decent 10/11 brake flare spanner.

 

[DaveMcT]

Maybe I gave the wrong measurement. But its an ordinary IMPERIAL flare nut spanner. The metric I bought were loose or would not fit the nuts.

When I have time to bother looking for it, I'll take a photo. The point is don't assume that metric flare nut spanners will do the job.

 

[Yolanda]

I've bought a set of US Pro Industrial 4 piece 9_15 mm I've tried them all on the appropriate nuts and they are all a good fit.
NSR wheel cyl now changed.

 

[koalar]

Thanks @Yolanda for the update

US Pro Industrial is not a manufacture I have own. Good to know they were up to the job

 

[Yolanda]

I've a few bits and bobs by US Pro they seem of good quality, but only time will tel. When I was on the spanners full time I mostly bought Britool and the like which I've still got. But nowadays lesser known brands ( Silverline comes to mind ) do the job.