pvb
Well-known member
Can I suggest you address your complaint to Volvo Penta?
Volvo 2001 banjo bolt torque setting
- Thread starter Dipper
- Start date
Can I suggest you address your complaint to Volvo Penta?
AntarcticPilot
Well-known member
A few years ago I sheared a banjo bolt on the fuel system of a VP2003 by overtightening it, and I wasn't using that much force. The thinnest part of the metal is the neck below the head, where the radial hole is bored. Volspec provided a version made to their own pattern which is much more robust; the originals are apparently no longer available, and Volspec agreed that they are a poor design.
I'd advise light finger pressure and then maybe a quarter turn, or more if required to make a seal. The torque settings in the manual are for solid bolts, not banjo bolts, and I doubt that the original banjo bolts would even take 20Nm.
I'd advise light finger pressure and then maybe a quarter turn, or more if required to make a seal. The torque settings in the manual are for solid bolts, not banjo bolts, and I doubt that the original banjo bolts would even take 20Nm.
Ceirwan
Well-known member
70nm seems a little excessive for a banjo bolt, if you've done a few before then bolts with copper washers can normally be done just through the feel of them as you tighten them up.
This chart on Hose & fittings seems to suggest 20nm is correct for a 12mm bolt.
However last time I had it apart I put it back together with Dowty washers, just a little nip is adequate to get a good seal & they are far more reusable.
This chart on Hose & fittings seems to suggest 20nm is correct for a 12mm bolt.
However last time I had it apart I put it back together with Dowty washers, just a little nip is adequate to get a good seal & they are far more reusable.
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VicS
Well-known member
If the bolt screws into a aluminium alloy casting , as Dipper suggests in #7, of course the table of torques quoted from the manual does not apply..
Dipper
Well-known member
That sounds a good idea.
jwfrary
Well-known member
Dowty washers are a good recommendation, table looks good.
I have had more apprentices shear things off with a torque wrench than anything else!
I needs to be used for the right application. Wheel nuts, cylinder heads, that kind of thing.
This type of fixing only needs to be tight enough to seal.
If your really into torque specs get yourself a zues book, it has all the torque specs and settings for material and bolt construction and tensile strength.
The quoted volvo table is for high grade metric bolts. A lot of banjo dont even have metric corse threading anyway!
VicS
Well-known member
Bilgediver
Well-known member
VicS
Well-known member
The only reason to quench is to cool the job quickly. Useful for large objects to allow work to continue without unnecessary delay.I am of the quenching clan
Boater Sam
Well-known member
Quenching copper is not necessary but maintaining it at red heat for 3 to 4 minutes is advisable to fully anneal.
Boater Sam
Well-known member
pvb does not have it in him to admit an error or mistake. Which is why I ignore him.
Ceirwan
Well-known member
The engineers bible!
I still have the copy I got on my first day as an apprentice. That said its looking pretty dog eared now.
Dipper
Well-known member
Thanks for all the input folks. It looks like I have been doing it correctly. In the past I have either used new washers or annealed the old ones. On this occasion, I had tightened the fitting enough to stop it leaking when the engine wasn't running but it weeped when (presumably) a bit of pressure or vibration built up. I have refitted these several times with no previous problems but they do worry me.
There doesn't seem to be a Volvo torque specification for this bolt and it relies on experience to feel when it is tight enough. Ceirwan's chart gives a guide and I will probably use Dowty washers when I next remove it. Thank you for that.
There doesn't seem to be a Volvo torque specification for this bolt and it relies on experience to feel when it is tight enough. Ceirwan's chart gives a guide and I will probably use Dowty washers when I next remove it. Thank you for that.
Bilgediver
Well-known member
The necessary torque for these will be low as the banjo bolt is thin walled so easy to fracture, unlike a solid bolt the same size. In order to reduce the chance of overload hold the spanner close to the bolt end and if torquing I suspect the value is around 20 ft lbs in old language which is actually the torque for some much smaller solid bolts Dowty washers are ideal for these . Take your choice but note they are not sized by actual bore but the pipe size over which they fit.
British Standard Pipe Thread (BSPT)
| BSP Thread Size | Outside Diameter mm / inch | TPI |
|---|---|---|
| 1/4 Inch BSP | 13.16 mm / 0.518" | 19 |
| 3/8 Inch BSP | 16.66 mm / 0.656" | 19 |
| 1/2 Inch BSP | 20.99 mm / 0.825" | 14 |
| 5/8 Inch BSP | 22.99 mm / 0.902" | 14 |
Amazon Washers
Amazon.co.uk : dowty washers 1/2
jwfrary
Well-known member
Thats it! My front page fell off years ago!
penberth3
Well-known member
I've never seen any torque figures in a Zeus book. What edition have you got?
Bilgediver
Well-known member
They would be over the top if they were there. They would not be correct for thin walled hollow banjo bolts.
penberth3
Well-known member
Er, yes, that's already been made clear further up the thread. Are there any torque figures in the latest Zeus tables?