MOT booked for Monday and whist it is in asked my friendly garage owner if he will remove/replace the bolts or studs securing the exhaust to the manifolds, Trying to make it easier to remove when I come to do the rear beam bushes.
MOT and prep
- Thread starter Brian4
- Start date
I good idea Brian, fore thought is always a winner.
Tony.
Tony.
Never fancied struggling on axle stands, on my back,can't see properly when the garage has a ramp and a nice torch to warm things up all at eye level.
Great idea Brian, should help you when you come to remove them.
As you probably read in the Zed Shed series exhaust bolts are the biggest cause of swearing! Annoyingly there isn't really any easy way to tell the condition until the car is up in the air and you attempt to loosen them. I'd recommend to anyone carrying out a sub frame refresh to get it to an exhaust centre or garage first and inspect it up in the air. If it's all good then you have only wasted 30 minutes and a few quid of someone elses time!
All passed ok so pleased emissions seem to be well in as well.
As to removing the bolts he TBF but we have come up with a plan.
First of the 4 bolts he tried was the easiest to get at and even after heating well sheared so eventually got the remaining part out and replaced and the plan is to cut the pipe between the joint and back box in a convenient place and fit a support clamp around the joint. There is the clamp on the parts diagram so I gues this is used when a replacement exhaust is fitted. Also makes the exhaust easier to handle when removing it. Just got to source one now measure the pipe first.
Also no charge for labour or 3 drill bits he broke getting the old stud out proper friendly helpful garage and will continue to use them even though most of the time it is just for an MOT so very little value added work.
As to removing the bolts he TBF but we have come up with a plan.
First of the 4 bolts he tried was the easiest to get at and even after heating well sheared so eventually got the remaining part out and replaced and the plan is to cut the pipe between the joint and back box in a convenient place and fit a support clamp around the joint. There is the clamp on the parts diagram so I gues this is used when a replacement exhaust is fitted. Also makes the exhaust easier to handle when removing it. Just got to source one now measure the pipe first.
Also no charge for labour or 3 drill bits he broke getting the old stud out proper friendly helpful garage and will continue to use them even though most of the time it is just for an MOT so very little value added work.
He made hard work of those studs Brian, all you need to do is heat the flange and they will punch out quite easily.
Tony.
Tony.
Might have another go then Tony.
Done a lot at work Brian, heat the flange to cherry red and they do punch out, but you do have to have it red!
Tony.
Tony.
Just a quick question, coming from the oil & gas biz, I know that above is done all the time but does it not change the mechanical properties of the material, as 'heat treatment' will harden the material.
Yes it will Mike, but that part of the exhaust is almost up that sort of temperature when its running anyway. That's also why they're such a bi*** to try to drill out. The original studs are an "interference" fit (pressed in bloody tight). They only use studs and nuts to facilitate ease of fitting on a production line.
Tony.
Tony.
Acousticplayer
Zorg Addict
Hey Brian what garage you using.
Hi Dave it is one local to me not a BMW specialist but very helpful.
Only if you fast cool the steel. If you leave it "air cool" it will normalise the steel or return it to its mild steel state. Unless of course it is a special hard steel which is unlikely.
They thought us, as apprentices at Agricultural College in the forge, how to temper steel and how you soften copper by heating it cherry red then quenching it in cold water which is the opposite to steel.
Tony.
Tony.
In laymans terms to harden steel its heated to 850 ish depending on its alloying elements and then fast cool it in water or oil, again dependant on alloy elements.
To normalise, anneal or soften you let it cool slowly.
Copper (and aluminium) is a metal that work hardens very quickly. I'd have thought slow cooling was required to bring it back to its normal state.
I may be wrong as 'er indoors keeps telling me quite often
To normalise, anneal or soften you let it cool slowly.
Copper (and aluminium) is a metal that work hardens very quickly. I'd have thought slow cooling was required to bring it back to its normal state.
I may be wrong as 'er indoors keeps telling me quite often
My dear departed father in law proved this to me one night, over in his HGV workshop we couldn't get a plug to seal and had no new copper washer, so Reg heated it up and ran the cold tap over it, refitted and tightened it. Hey presto no leak.
Tony.
Tony.
Tried this on mine, I was shining it on the bolts for ages until the batteries ran out, made no difference whatsoever...
When I started riding, all those years ago, it was standard practice to anneal copper plug washers before reusing them. Now they appear attached to the plug. Also the plugs could be taken to pieces for cleaning. Those with cash had a small box filled with steel needles. The plug screwed into the top and shaking the box cleaned the plugs. I had and still have a see through plug which allows the combustion to be actually seen. (Sparkrite?)