F08 Calipers with Leaky nipples

[Laverdaton]

I have F08 calipers on the front of my ?76 3CL (Ceriani forks), both calipers have a continual weep  from one bleed nipple one each caliper.
Both calipers have had repairs to the nipple area and the thread is now M7 instead of M6 for all four nipples.
I suspect the tapping drill has touched the nipple seat?anyway they leak!

What are my options to repair - - can they be repaired?

Can I replace with P08?s (more widely available) and put a threaded insert in the 2 x mounting holes?

What is the  nipple seat angle for the original size nipple??.and is the nipple angle a universal standard angle for nipples?.
It might be that the M7 nipple seat angle is different I won?t get the sealing effect from the M6 original nipple!

Andy

 

[Ernesto]

Damaged seat, for the bin.
No problem using the newer type without threads.
Either use an insert thread like timesert, or longer
bolts with countered nuts.

hth
Ernesto

 

[Tippie]

I have used a ball bearing under an Allen screw instead of nipple for decades with no ill effect. Bleeding is messy and requires a wash afterwards but rather than junk an otherwise good caliper I took that option. Could do the same with a flattened off nipple.

 

[Grant]

If you replace with unthreaded F08s then bear in mind you will likely need to shim out the caliper to centre it to the disc.

 

[2622]

I have F08 calipers on the front of my ?76 3CL (Ceriani forks), both calipers have a continual weep  from one bleed nipple one each caliper.
Both calipers have had repairs to the nipple area and the thread is now M7 instead of M6 for all four nipples.
I suspect the tapping drill has touched the nipple seat?anyway they leak!

What are my options to repair - - can they be repaired?

Can I replace with P08?s (more widely available) and put a threaded insert in the 2 x mounting holes?

What is the  nipple seat angle for the original size nipple??.and is the nipple angle a universal standard angle for nipples?.
It might be that the M7 nipple seat angle is different I won?t get the sealing effect from the M6 original nipple!

Andy

Sounds to me that when someone has drilled them out for the bigger thread that they have not been dead square to the original hole as technically the angle of the seat should not be that big a deal as the interference between the two angles is what does the seating.

Andy what you might be able to do is get one of the bleed nipples out, measure the diameter of the part under the thread, ie: the bit that is just above the taper, then sacrifice it ( 7mm ones are available to be had ) by drilling the centre out of one with the exact size drill bit and then use it as a guide. You then screw it in one hole at a time and use the drill bit in a drill at say slow to medium speed to lightly touch down on the seat which will then clean and square it off.. this should make them again concentric and square to the nipple bottom.

That is what I have done and it seems to work.

 

[sfcpiet]

Sounds to me that when someone has drilled them out for the bigger thread that they have not been dead square to the original hole as technically the angle of the seat should not be that big a deal as the interference between the two angles is what does the seating.

Andy what you might be able to do is get one of the bleed nipples out, measure the diameter of the part under the thread, ie: the bit that is just above the taper, then sacrifice it ( 7mm ones are available to be had ) by drilling the centre out of one with the exact size drill bit and then use it as a guide. You then screw it in one hole at a time and use the drill bit in a drill at say slow to medium speed to lightly touch down on the seat which will then clean and square it off.. this should make them again concentric and square to the nipple bottom.

That is what I have done and it seems to work.

(bigthumb)  Way to go... but I like Tippies' method as well!

piet

 

[Dellortoman]

I have F08 calipers...
Can I replace with P08?s ...

Hang on a second. I just have to engage pedantic mode ...

[pedantic]
There isn't such a thing as a Brembo P08. The caliper designation is P2 F08. It comes with the mounting holes threaded or un-threaded depending on the way it bolts to the fork leg.
[/pedantic]

Cheers,
Cam