Lunched brake bleed screw thread

try re tapping it first with a tap the same size as the bleed screw

Forget it. Even if you could find a larger one, the taper seating at the bottom of the hole would need re-machineing.

Is the caliper exclusive to Alfa? I'd be surprised if it was.

drill out and re tap with fine thread and fit a bolt, you can still bleed by slackening the bolt when needed.

not good practise & I wouldn't recommend it as it wouldn't seal correctly, as Dave said in an earlier post its machined tapered, not only into the bottom of the caliper where the bleed nipple goes, the bleed nipple its self is tapered for obvious reasons.

Agree totally. What I should've said is that I've seen oversize ones mentioned for this very purpose, although where one can purchase them I don't know

I'll have to become a bit more resourceful and find out. You're probably right and it's not, although I'm loath to swap a known good caliper for a few mm of thread unless I have to.

Thankyou

Um...not sure if im too keen on that idea either...

Oops...sorry for all these multiple posts.

Now I've managed to get a better look at it, I can see that the bottom on the thread seems ok, about half way up it's been stripped. Makes me feel slightly better that it looks like it's been done by a previous owner and not me. Wondered why it suddenly refused to tighten - I must have slackened it a bit more than I ever had previously.

As Steve suggested, I'm going to try retaping it the same size and see how I get on.

I'll let you know.

Many thanks

Make sure you use the correct type of tap pitch taper etc

its only a hole for re leasing fluid when you want to, anything with a sealing washer will do, no need to get too technical, had same thing on sri for ten years with no problems, bleed screws on calipers are crap , good quality bolt and washer will last for years and years.

Well if it's shared with other cars get a seal kit and overhaul the 'new' one. It's pretty simple to do.

I'd say it might be difficult to get the right tap? Looks a pretty fine thread. Just a guess, though.

Seems the makers have got it wrong again, then. Given the vast pressures involved I'd prefer a properly engineered seal to a 'bolt and washer'

a bleed screw is only a modified bolt.

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Yes, but modified in such a way that it, and the seat into which it fits, make a seal capable of containing very high pressures reliably for many years. Using the head of the bolt will mean, for a start, that you're exerting many times the load on the threads because of the much larger areas involved.

I wouldn't bother. If the first half of the thread is stripped, that's about as far as the bleed nipple screws in. Safer to have a thread insert fitted and know that it wont suddenly fail. Mike.

Wrong. About the only thing a bleed screw has in common with a bolt is the thread and a hexagon to turn it. It is a valve. A crude one admitted, but a valve nevertheless. Mike.

Easy enough to have made if you know what you want. Best bet though is to have a thread insert fitted, and use std nipples. As for remachining the seat, see my earlier reply to Dave. IMO it's easier to retap accurately, rather than worry about remachining the seat. Mike.

Not necessarily. Depends how carefully it's tapped. I've just fitted 2 thread inserts to a mates caliper. Screwing the new nipples in with engineers blue, showed them seating perfectly on the original seats. Mike.

Shouldn't be a problem. Being european the chances are that it's a 10mm x 1mm pitch. Even if it's not, there are only about 5 different threads used for bleed nipples. Taps easily obtained for all of them. Not that I would advise using one anyway. The right way to repair it is by fitting a thread insert. Mike.