ACEngineering
Member
- Location
- Oxon
If you dont have a feel for it the length isnt important!
Question for mechanics
- Thread starter agri knives
- Start date
If you dont have a feel for it the length isnt important!
- Location
- Scottish Highlands
Had the head skimmed on a Peugeot 504 many years ago and got a declared "expert" to refit it. A few weeks later the head blew again. This happened twice more, so (as I do) I phoned Peugeot and spoke to a technician.
The Technician said, as above, torqued bolts can stretch and lose their temper. They should either be replaced or, if you are really mean, you can measure them to check that they haven't stretched.
I shall continue to annoy the technicians who know by asking questions and have learnt not to rely on experts. BTW, an expert is someone who knows more and more about less and less until he finally knows absolutely everything there is to know about nothing at all.
The Technician said, as above, torqued bolts can stretch and lose their temper. They should either be replaced or, if you are really mean, you can measure them to check that they haven't stretched.
I shall continue to annoy the technicians who know by asking questions and have learnt not to rely on experts. BTW, an expert is someone who knows more and more about less and less until he finally knows absolutely everything there is to know about nothing at all.
Ideally new studs are good practice but I don't think used studs caused the problem. A clean with a wire wheel and tap and die, have a good look at them, lightly lubricate and I can't really see any problem re using them. Remember the manifold isn't really under any pressure apart from the weight of it and turbo, unlike head studs. Sweeten everything up then start tightening from the centre working outwards. A decent mechanic will have a good feel in his hands when they are torqued. Not defending ur main dealer/mobile mechanic/expert, why did he not put it right?
I was thinking that the previous guy didn't do it by the book ,there maybe a case to answer
dee
Member
- Location
- Derry/Londonderry
So then why are you undermining his judgement by coming on here and questioning should new studs be fitted or not
Speedstar
Member
- Location
- Scottish Borders
- Location
- 200 miles N,NW of New York
Ha the age old trick of knocking someone else's work, its been done since Adam was a lad,
You made the decision to get the man to do it 300 hours ago, and yes things go wrong, but looks like you never been in touch to get him to sort it, instead you get someone else to look, not saying 1 st man is good or bad at his work, and same goes for second,
The difference is if the 1st man would sort it and stand behind his work, to which it seems you never give him the chance,
As for the bolts, I would of fit new, do job right first time, then it may cost a bit more, but happy customer,
Things do and will go wrong, its how its sorted out that counts
You made the decision to get the man to do it 300 hours ago, and yes things go wrong, but looks like you never been in touch to get him to sort it, instead you get someone else to look, not saying 1 st man is good or bad at his work, and same goes for second,
The difference is if the 1st man would sort it and stand behind his work, to which it seems you never give him the chance,
As for the bolts, I would of fit new, do job right first time, then it may cost a bit more, but happy customer,
Things do and will go wrong, its how its sorted out that counts
I’m with this.. plenty of bolts and studs will reuse fine. I’ve not seen a problem. If rusted or dodgy Then of course change them, buts it’s got a lot to do with taking the time to clean mating surfaces properly and running a die over slightly rusted threads And a bit of oil so the nuts actually clamp the parts and not just bind up on the threads..
agri knives
Member
- Location
- middle of ireland
agri knives
Member
- Location
- middle of ireland
Not on a valtra .Because his spanner man has never worked on a valtra engine before
Gapples
Member
I am surprised at the second bloke blaming the first, unless you are nailed on certain you are right, as a techy you really have to be very careful what you say, it can easily come back & bite you on the arse.
No matter how long you work on at a job you can can still be tripped up by something simple.
Anyway my take on manifold bolts is it's largely down to what engine you are working on.
Obviously I did IH & CaseIH all my working life & on IH engines with stud & nut set up I can't remember an issue really, I've reused them plenty times without problems.
On the Cummins manifold in the 7100 & 7200 magnums though you wouldn't dare put the old bolts back in, the original one were bad enough for breaking as it was & a right pita to drill out !
Hopefully though your second guy will have sorted the job this time.
agri knives
Member
- Location
- middle of ireland
This is a Cummins engine , so you have nailed it.
I once posted on here a (interesting to me) post about bolts.... I dont really know how to find it easily...
Anyway, 80% of the tightening torque is used to overcome friction in the thread and under the head of the nut/bolt.
So, rusty/rough threads will have practically no clamp load, compare to fasteners wich are over lubricated can often snap before reaching the correct torque.
ridger
Member
- Location
- Tyrone, Northern Ireland
I wouldnt say too much, you might be glad of him some dark night if you are broken down
Green&Steam
Member
Definition of a expert
X. Is. A unknown quantity
Spert. Is a drip under pressure
X. Is. A unknown quantity
Spert. Is a drip under pressure
ACEngineering
Member
- Location
- Oxon
Bolts with pre dried loctite can be a pain too!
By the time you wound all the bolts in so the item is seated and square the loctite has set and you loose most of your torque overcoming the set loctite to finish the bolts off!
Theres a certain bolt I do quite often and I actually scrub off at least half the loctite before I start fitting or sometimes all of it then use a normal wet loctite.
Speedstar
Member
- Location
- Scottish Borders
Fastrac engine they are bad for breaking the manifold bolts
- Location
- The North
im with you and him!
have to say ive fitted numerous turbos and manifolds when i was a mechanic and rarely changed studs (only if obviously problematic) never had a problem with any,
my big concern was oil feeds and gaskets, if you swapped it all and there a problem here its a big issue. done a few agri manifolds but not loads.
could be simple case he did them all tight enough to nip them but forgot to torque them up, really easy done and would prob reveal its self in the hours you quote.
Deerefarmer
Member
- Location
- USA
I would have to agree with what different posters already said, 6.8 mechanical powertech deeres I've reused manifold bolts many times, our early 800 fendts had a lot of trouble with manifold warping and snapping studs, wouldn't think of reusing bolts, all depends on what your working on
I would tell the first mechanic what went wrong so that he could possibly learn from his mistakes... we all had to learn and made some mistakes in the process
I would tell the first mechanic what went wrong so that he could possibly learn from his mistakes... we all had to learn and made some mistakes in the process
- Location
- northumberland
Time to knock the dust of that tool box in the garage GA
