I'm just replacing the P16 calipers on my car with a pair of M16. When I was tightening up the female nut to the male end of the braided flexi I
noticed the copper pipe was twisting with it, albeit not the same amount. I reckon the pipe has about a quarter turn longitudinally in it now and
there are stress marks in the surface of it. Should I have lubricated the end of the pipe/fitting before attempting to tighten so that the flare just
gets squashed and not rotated?
Regards,
David
No lubricant needed , in fact it could cause problems later. When using copper pipe you should ideally be using brass fittings but loads of people including me have used steel fittings . Copper pipe is softer than Kunifer and steel pipes so more likely to twist especially if over tightened or the wrong type or poorly made flares are us d.
I always lubricate the pipe above the flare and the inside and outside of the flare nut, making sure the sealing face of the flare is clean before assembling. No science to back this up practice but I've never had any problems and I tend to own / maintain the same vehicles for a long time, I've currently got a VW Polo which I've had for 13 years and a Merc Sprinter which I've had for 10 years, both of which have had brake pipes ages ago.
red grease
Why do you suppose vehicle manufacturers don't use any lubricant. In over 50 years in the motor trade I have never needed any or know of anyone else that has!
quote:
Originally posted by rusty nuts
Why do you suppose vehicle manufacturers don't use any lubricant. In over 50 years in the motor trade I have never needed any or know of anyone else that has!
quote:
Originally posted by rusty nuts
Why do you suppose vehicle manufacturers don't use any lubricant. In over 50 years in the motor trade I have never needed any or know of anyone else that has!
I was trained as a motor vehicle technician when the term technician meant something unlike school leavers that call them selves technicians Having worked on cars from Model Ts to Aston Martins, Ferraris and Rolls Royces to name a few I've probably had far more experience than both of you put together. Do you really think that a bit of lubrication put on now is going to help when undoing brake fittings in 10 years ? Besides which any oil , grease etc can have unwanted effects on braking systems . If you don't agree then I will bow down to your obviously qualifications.NOT.
quote:
Originally posted by rusty nuts
I was trained as a motor vehicle technician when the term technician meant something unlike school leavers that call them selves technicians Having worked on cars from Model Ts to Aston Martins, Ferraris and Rolls Royces to name a few I've probably had far more experience than both of you put together. Do you really think that a bit of lubrication put on now is going to help when undoing brake fittings in 10 years ? Besides which any oil , grease etc can have unwanted effects on braking systems . If you don't agree then I will bow down to your obviously qualifications.NOT.
quote:
Originally posted by rusty nuts
I was trained as a motor vehicle technician when the term technician meant something unlike school leavers that call them selves technicians Having worked on cars from Model Ts to Aston Martins, Ferraris and Rolls Royces to name a few I've probably had far more experience than both of you put together. Do you really think that a bit of lubrication put on now is going to help when undoing brake fittings in 10 years ? Besides which any oil , grease etc can have unwanted effects on braking systems . If you don't agree then I will bow down to your obviously qualifications.NOT.
Ego warning! anyway personally I don't use any lubricant on the fittings, the pipe shouldn't really be twisting with the fitting or being wound up. If it
has marks from this and I think I have seen this before (light lines spiralling round) I'd probably want to replace the copper pipe tbh safety
first...
My gut feeling is that the flair is not correct and it is not seating correctly, seating more in the nut than the flexi and hence then turning with
the nut...I'd have a very careful look at the appropriate one required for the braided flexi, it may very well be different to the standard
hose.
I'd also recommend you replace hoses much more often than every 10 years.
In all probability the flare isn't quite right. I was planning on replacing the pipe anyway as I don't like the idea that there are stress marks; definitely don't want it to split under stress.