7 replies to this topic

[welshy]

Model:Mini MR2
Year:1989/1997
Description: 175BHP of the best Britishpanese Engineering

Hi,

I have read many interesting posts on the sheared bleed nipple issue and i too am suffering from the same problem (all 6 nipples on some calipers from Ebay (that will teach me).

I have aquired some M10 x 1.0 bleed nipples and wondered if any one knows the drilling and tapping detail for bleed nipples to ensure they seal (ball bearing option is an unwanted last resort).

Cheers
Welshy

[Bungle]

have you tried running a ice cube around them ?

[Big_Adam]

If you find your nipples are too big then they can be removed by any good body mod artist who's up for doing it. I suggest Canada or similar as they allow for the uses of anaesthetics from anyway (to a degree).

How ever if your nipples are large and raised then it may be due to a chemical imbalance, in which case removing the nipples (just the skin) will result in the return of swelling as the areola. Removing the areola meaning making deep cuts into muscle and blood system in the area. Suggest a good doctor (who will never do it as it doesn't have any benefit to the patient) or again a body modder who is willing to do the job.

But, if it's just calipers we're talking about then I suggest a good machine shop.

[koomey]

have you tried running a ice cube around them ?

ha ha ha hah ha haha ahahahahahahaha

[Ethel]

The problem is the nips seat on the conical face at the bottom of the drilling, you may have difficulty maintaining or cutting a new seat while drilling and cutting the thread. I'd think it would be easier to fit a threaded sleeve to restore the original threads. Snapped nips will mostly be down to them being overtightened.

Realising that the screws may still be in there... you could try drilling close enough to be able collapse and pick out the remnant of the nipple. The tap drill size for 10x1 is 9mm.

[dave21478]

^^^ yup, the angle of the seating face at the bottom of the hole is critical for the nipple to seal against. Cutting that angle properly is not something I would be confident doing. I personally would prefer the ballbearing method rather than try to recut to a larger size, assuming all other efforts to get the original out have failed.

[welshy]

thanks for the replies and I deserved the sarky ones. The complexity of the machining isn't a problem as I work for a large engineering company I am just after drilling and tapping details.

[dklawson]

Well, if you don't want to try the ball bearings (and thank you for using the search function to read up on the old threads about this) then you certainly can re-machine your brakes for the M10 nipples.

However, I don't think you're likely to get the information you need here. I suggest you work backwards from the nipples you bought. Look up which cars they are used on and if possible visit a scrap yard and get a junk caliper from one of those cars. Bandsaw through one of the bleed ports but leave enough material behind that you can set this up on a mill and machine down to the port centerline. This will allow you to carefully measure the port profile for the M10 nipples and duplicate it. Be sure to check the class/fit of the female threads.

The basic port profile will be a carefully drilled pilot hole that is tapped almost full depth. I suspect what you'll find is that the pilot drill is smaller than what would normally be used to produce the typical 75% thread engagement. A bleed nipple will benefit from a tighter fit with more thread engagement to keep it perpendicular and concentric with the port.