Tell you what.........as you have doubts about the answers already given, you obviously know the real answer....... ....are you going to keep it a secret? Thought so..........
If my mechanics do a bleed nipple up without torqueing it they get a bollocking. Use a Torque wrench with a suitable range, i.e. less than 0-30Nm. 12Nm as already suggested sounds good to me. Forget all the non sense about lubricated or not lubricated threads, in this case by there nature the threads will have a little brake fluid on them, like wise the compression/ tension is irrelevant, 12nm is what is stated. It is absolutely good practice to do torque bleed nipples, and will ensure longer more reliable service from the components.
Is stated where? Is that in an aluminium or steel caliper? Is that a steel or aluminum nipple? Just do the buggers up until they don't leak........
I was quoting an earlier post, which had stated Ducati recommend 12NM. We all know damned well w are talking about an aluminium caliper, with a steel bleed nipple, never seen an alloy bleed nipple. Of course you can just tighten them till they don't leak , and strip the threads or round the hex of the nipple. If you have an issue with the seat just leaning on it till it stops is not good. I've no doubt most competent mechanics will have no problem doing it by feel, but that's not what the OP asked. Just telling someone to nip it up is poor advice.
Its not. Have you ever had a nipple snap in the caliper when you try to loosen it to bleed? Due to someone over tightening? I have and its a freaking pain in the ass and resulted in two new calipers. Grease the thread and nip it up with a stubby. Thats experience talking.
No, that;s not experience talking.........its book learning. You said it yourself.....'most competent mechanics can do it by feel'......... ...as you seem to need a torque setting to do it, that suggests you can't do it by feel.......therefore you aren't competent and not experienced. In the Ducati workshop manuals I have here, there is no mention of a torque setting for a brake bleed nipple. Calipers don't have to be aluminium.....I have worked on plenty of steel and cast ones...and you know as well as I do, there are steel, aluminium, tungsten, brass and stainless bleed nipples. I own three torque wrenches and have never used them on anything let alone an effing bleed nipple and I have never broken a bleed nipple when tightening it or had one come loose........in 35+ years........and I haven't had one leak either, unless it had been mullered by a previous 'expert'.
I sense some tension here. 20 years Motorsport experience including involvement in the design and development of brake calipers and systems. I'm never to proud to look something up, I'll never assume a torque setting if I have a reference. If I were to read that a Ducati bleed nipple should be torqued to 120nm, I would use my experience to determine that was typo.
No tension Dunc But these are things I rely on 'feel' to tighten. Bikes ridden in all weathers can get a bit neglected on the caliper front. Salts etc and overtightening can cause issues. A simple nip for these is all that is required unless I guess you are racing etc. Having the bastards sheer on the caliper is a nightmare. Drilling didnt help as it fucked up and you cant reliably helicoil these. Besides I nip at 12nm. Probably. hehe
Possibly the wrong thing to say, but IMO if someone can't do up a bleed nipple without relying on manuals and torque wrenches, then maybe they shouldn't be doing their own maintenance....... ........I have had plenty of bikes and cars where the previous owners have owned 'all the gear and manuals', but should never been allowed near a spanner, let alone a vehicle.
Ive had to get the mole grips to these in the past. I mean, theyre hardly mission critical so why overdo it. I had to use a 12ft scaffold pole on a VW hub nut once. 3 of us. 2 on the pole and one making sure the socket was seated square. The other 3 were easy and they never fell off so why was this bastard one subject to a strong atomic force.
Like everything in life, get enough blokes in one place and all of them will have an opinion that differs from everyone elses. However the consensus seems to be 12Nm and I was forgiving. As I never pulled anyone up for stating 12nm. Its a capital N as its after a person. Newton. Like W for Watt or J for Joule and Pa for Pascal.
