458 458 Brembo Caliper Bleed Nipple Issue *happening now…urgent!*

Remove the bleeder to determine whether the threads are stripped on the bleeder (hopefully) or the caliper (ugh). Post photos.

 

The bleeder hole is a tapered (pipe) thread so even if it's stripped, you should be able to rethread it to a larger size and obtain a bleeder with larger tapered thread. This will almost certainly involve disassembly of the caliper but that sure beats buying a new one.

 

Based on the photo, I would get a new bleeder and chase the threads in the caliper with the proper size tap.

 

Chase the threads means to slowly and carefully run a tap into the bleeder hole in the caliper. Doing this may prove successful in cleaning the threads in the caliper and restoring them to usable condition. 1/4 turn in, then all the way out to capture any metallic chips that collect on the tap. I do not know the thread size but it's almost certainly metric. I'd order a couple new bleeder valves and match up the threads with a tap.

 

No. The taps have small indentations in them which allows loose material to collect there. That is exactly what you want. I would try to match the tap that closest fits the caliper threads.

It looks to me that someone before you may have done some sloppy work, perhaps got it cross threaded. Not the end of the world, I certainly don’t see why the caliper should need to be replaced. Just take your time and make sure the tap goes in straight. And bleed the system well after performing.

I’ve done my share of rethreading over the years…….

 

I would but do it by hand first to get a feel for the condition of the threads. How do the threads in the caliper look? The threads on the bleeder valve are sure buggered up.

 

The extra material on the bleeder screw is aluminum that has been pulled out of the caliper. The threaded whole in the caliper is now too large for a new bleeder to tighten into. An insert / Helicoil needs to be installed by an experienced technician.
Il

 

That ain't gonna work...

At a minimum you are going to need to repair the threads in the caliper with what is called a Time-sert in order for this to be safe to put back on the road. Either that or a Brake bleeder repair kit.

Brake line pressure usually is around 800 to 1200 PSI in most cars. Given the surface area of the bleeder valve, you could still be seeing several hundred pounds of hydraulic force attempting to push that bleeder valve out.

A new bleeder with fresh threads will help your cause here, but chasing the threads in the caliper w/ a metric tap isn't going to magically repair the compromised aluminum threads. Yes, it will push the aluminum back into what appears to be "threads", but most likely under the required torque to seat the bleeder property, it will most likely shear the threads out again.

You might get away with it by catching a few remaining thread in there, but do you really want to trust your life to it? I've had brakes fail while driving and it's a super scary event. Luckily I was near the house and only going 20-30 MPH on flat ground, but having any sort of line pressure failure causes the entire system to pressure to drop to zero basically. Ferrari might use independent systems for front and rear brakes, but even so it's a big risk.

Again, the correct way to repair this is using a Time-sert. Cut new threads in the caliper using the special Time-sert tap, install the time-sert sleeve using either Red loctite (271) or green retaining compound (Loctite 680) and then thread the bleeder into that. I sometimes also install the Time-sert using JB weld. Either way, make darn sure you know what you are doing, since the bleeder has to seat properly at the bottom. That means you have to be very careful not to damage the seat when cutting in the Time-sert and it must not block the bleeder from touching the seat area.

The other option, as mentioned, is they sell Brake bleeder repair kits. I've never used one myself, but from what I can tell, they use a NPT plug and then a bleeder valve inside of that. You can find them via a search on Amazon or Google.

Basically, if you do not have skill as a machinist, this isn't a job you should be attempting yourself.

Let me ask you this:

You said you bought a "metric tap kit". Tapes generally come in three styles: bottoming, taper and plug - and 2 out of 3 of those ain't gonna work for this job and will most likely destroy the seating surface. Even with the correct tap, you'll most likely need to modify it on a lathe or - minimum - bench grinder in order to pull this off even remotely correctly.

I would proceed with a lot of caution here unless you are fully confidence in your machining abilities. This is a deceptively simple job which has dire consequences if botched.

Ray

 

+1

I wouldn't trust a Helicoil to anything outside of an exhaust stud. For a brake repair on a car that does zero to sixty in 3 seconds, you need a Time-sert minimum. I would strongly suggest bearing retaining compound to hold it in place:

https://www.henkel-adhesives.com/us/en/product/retaining-compounds/loctite_680.html

Also you want to prime the surfaces with primer prior to applying the 680. I use Loctite 7649 primer here for this sort of work. You get about 5-10 seconds to assemble everything and after that it's never coming back apart.

Ray

 

M10 x 1.00

Ray

 

A word of caution if you've never used a Time-sert before. First, I'd practice on some dummy aluminum with a hole in it.

Second: do not use the drill bit in the kit in any sort of power drill. The bit is razor sharp; you can simply chuck it into a T handle tap and turn it slowly by hand and cut the required hole. The drill will follow the old damaged threads and cut them out no sweat. Just work slowly and by hand. Do not hit the seat for the bleeder tip.

Also, I'd recommend installing the Time-sert with JB weld and allow it to cure for 24 hours. Be careful nothing squishes out below the insert down there where the bleeder valve has to seat. You can use Loctite 680 retaining compound, but if you haven't used it before and aren't familiar with it, it can bind too soon and really ruin your day. My advice is stick to JB weld so you can have a window of opportunity for making adjustments and/or aborting mission and starting over.

Finally, the Time-sert kit includes an "installation tool" - which royally sucks. My advice would be to get yourself an M10 x 1.00 bolt and two M10 nuts... then jam the nuts on the bolt and use that to thread the insert into the hole. Once installed, back the rear jam nut away from the forward nut and slowly unscrew things.

Ray

 

It won't look factory.

Just the same... I'd buy it to have on hand in the event you screw up the Time-sert install

Ray

 

We are lucky to have guys like Ray on this forum.
This is not a repair job to be performed by an inexperienced person.
"Dead Straight" takes on a new meaning.