Lunched brake bleed screw thread

Only if they're treated like crap.

IME if the threads are greased, and a cap fitted, they never give any trouble. Mike.

The right way to repair it is retapping and fitting a new bleed valve that matches the new hole size and tapping , thread inserts are a bodge job

What nonsense. Have you any engineering expertise whatsoever? Bodge indeed. You couldn't be more wrong. FYI, in manufacturing, thread inserts are often fitted to original equipment, especially on components that might need frequent dissassembly, because they are actually stronger, and less subject to wear than a thread tapped into the virgin metal itself. I suggest you do a little research before you make such foolish assertions in future. Mike.

Have resorted in past , was motorcycle with alumium calipers, even s/h caliper was in second mortgage territory, had the mangled remains of the bleed screw aperture welded across and used bleed bolts form Goodridge, like standard banjo bolt with bleed screw out the top.

This will obvioulsy only work if you can orientate the bolt to be at top during bleeding, even umnounted.

Bodgemungous

Adam

in the motor trade the only time we have used thread inserts is where the spark plug thread gets damaged or the thread in the sump where the sump plug goes & a few other various stud threads, ive never heard of it being used anywhere in the braking system though.

I was referring to thread inserts in general. Far from being a "bodge job" as Steve Robinson said, thread inserts are an improvement on threads tapped into base metal. They are stronger, more hard wearing, and less likely to sieze, as most are made from hardened stainless steel. They are particularly appropriate in ally. The reason they are not more commonly used is one of simple economics. A thread with an insert is more expensive to produce than one without, and for the majority of applications, they are simply not needed, but for the repair of stripped threads they are ideal, giving a repair that is actually an improvement over the original thread. Mike.

I was referring to thread inserts in general. Far from being a "bodge job" as Steve Robinson said, thread inserts are an improvement on threads tapped into base metal. They are stronger, more hard wearing, and less likely to sieze, as most are made from hardened stainless steel. They are particularly appropriate in ally. The reason they are not more commonly used is one of simple economics. A thread with an insert is more expensive to produce than one without, and for the majority of applications, they are simply not needed, but for the repair of stripped threads they are ideal, giving a repair that is actually an improvement over the original thread. Mike.

Yes mike inserts are often used but these are fitted by machine during the manufacturing process however the inserts the op is likely to get will be the spring wire type which come with a drill and a turn key to insert them , they are not designed for constant reassembly or tapered threaded holes

If the op wants to fit an insert he needs to take the calliper to an engineering shop where they can drill/ mill/machine the callipers bleed valve hole correctly and make an insert accordingly

As I said it will end up as a bodge otherwise

I thought we were talking about inserts in brake callipers not in general , totally different subject

You're just getting in deeper. I suggest you stop digging. Unless of course, you can tell me why inserts in calipers are a "bodge job" It doesn't matter where inserts are used. The advantages remain the same. A stronger, harder wearing thread than a plain one of the same size. Mike.

I'm sure you're just guessing about that. I've never heard of any machine designed for fitting thread inserts, and I've been in precision engineering all my working life. A typical application is on jigs and fixtures that might have interchangeable components. That being so, a machine to fit them is unecessary, apart from the fact that it would be horrendously expensive to design and make such a machine. If you know of one, I'd be very interested to hear about it.

however the inserts the op is likely to get will be

An insert is an insert. It's application is up to the user. AFAIA there are no rules as to where they should or should not be used. And of course they are not suitable for tapered holes, so why mention them?

As I said in an earlier reply to Dave Plowman. Providing care is taken, there is no reason why the bleed valve seat should need remachining after fitting an insert. Only last Thursday I fitted 2 thread inserts to a mates caliper, and I didn't need to remachine the valve seats.

Actually you didn't. You didn't qualify your bodge comment at all. "thread inserts are a bodge job" doesn't leave much room for misunderstanding. It simply tells me you know little about thread inserts. Mike.

mike we are talking about cars/ repairs / components not jigs

yes an insert is an insert , as an engineer you should also know that different types of insert perform differently , some suitable for single use others suitable for multi use

As we were talking about brakes , bleed valves etc I didnt think it necessary to qualify the comment I made .

Well, I tried retaping with the same size thread as suggested. I thought it was going to be successful for a second, but alas, it was not to be. Someone with more skill, experience, the right taps, thread inserts... could probably repair the thing, but I've since suprised myself that I can get a brand spanking new caliper for 65 notes at the most, so it's not really worth the headache nor the worry of bodging it.

Thankyou very much group for all the help and I apologise for any flame wars I've instigated in the retapping/thread inserts/bolt and washer debates :)

MikeL (Longtime lurker)

Heated debates are where we all sometimes learn from. ;-)

So am I. When are you going to realise that thread inserts are not specific to any particular application. As well as being fitted to jigs etc, it is a method of repairing stripped threads. Period. That includes their use on a cars brakes, engine, or any other automotive component.

When are you going to tell me about this machine that is often used for fitting inserts?

Examples please? I know of no thread inserts that are categorised in that way. AFAIA all inserts are suitable for single or multi use.

That doesn't alter the fact that your statement that :- "The right way to repair it is retapping and fitting a new bleed valve that matches the new hole size and tapping , thread inserts are a bodge job" Is wrong. It is not the right way, or even the best way IMO. When this is pointed out, you then make the excuse that you meant to say that if it were not fitted correctly it will end up as a bodge job, apparently forgetting that that qualification applies equally as well to remachining and tapping oversize for a larger bleed valve as it does to an insert.

I give up. It's quite obvious that you are wrong, but you're just not man enough to admit it. I know it, as no doubt others do if they've been following the thread. Mike.

Well to be fair, ReCoils aren't great if used repeatedly, they tend to unscrew, timeserts are brilliant but you'd never pay for them if you only wanted to get the bolt back in once. & you'd never use them on a brake cylinder :-)

you beat me to it

Depending on which model of 146 it is, it will share a caliper with the

Not entirely sure which models will share calipers, but I certainly know that the Marea 20v and Alfa 156 (all models) share the same brakes.

I could be smug and say I told you not to bother, but I wont. :-) When you said the first half of the thread was stripped I was sure that retapping wouldn't work. Bleed nipples tend to only use the first half of the thread, due to the extended end carrying the cone seat and side hole.

No need for you to apologise. Occasionally flame wars can be interesting. Mike.