Inspect your brake bleed nipples

philgarner

Member
Messages
226
Oooh errr etc.

I've finally had my GS out running for the first time in 2019 today due to a saga with the brake bleed nipples. It all started when I decided it was due a brake fluid change since it hadn't been done in my ownership (since 2016). I started on the OSR caliper and the inner nipple just span when I attempted to loosen it - all the threads inside had failed and there was no easy way to get it out. Next I tried the NSR caliper, and the top of the inner nipple sheared straight off, again no way to extract the threads. Bad times.

I then decided to cut my losses and take all the calipers off and take to a local engineering place to sort out. They did indeed extract and nipples and put helicoils in. So after they'd had them for 6 weeks or something I got them back. Then I put all the calipers back again, and tried to bleed again. Woes continued; most of the repaired nipples were good, but one of the helicoiled ones failed when tightening. There was virtually no thread inside it this time.

I decided to take dramatic action; by tapping out the bleed nipple hole to M12 and getting a special nipple to fit. This worked! All this took months and led up to today where we successfully bled the brakes and ran the car again.

TL;DR - brembo caliper nipples go bad when exposed to UK winters, check yours. There is a clearly a problem with these as I found an ebay shop, addiction motorsports, that sells all kinds of bits (like my M12 hack) to deal with these brembo nipples. They also have a rebuild service, which is what I should have done in the first place if I knew it existed: https://pro-calipers.co.uk/price-list
 

Zep

Moderator
Messages
9,110
I’ve heard of these failing too. I think lack of regular changes also contributes to the issues.
 

philw696

Member
Messages
25,114
Yeah the British Winter Weather is a killer its not just subframes that get attacked.
I have just made and replaced the small metal pipes from the Brembo calipers to the flexi hoses on the Boxster.
It took time and patience to get the nipples out on a 14 year old car but they all did.
To put it in perspective my 30 year old Renault 4 that I have just done front discs and pads on has its original metal pipes like new and she has done 100,000 miles.
The difference when roads are not salted.
 

TimR

Member
Messages
2,656
You know, it beats me that service techs dont just replace the nipples when they do the brakes, which should be often. For what they cost, and the potential aggro it saves, its a no brainer to my mind....! :whistle:
 

philw696

Member
Messages
25,114
You know, it beats me that service techs dont just replace the nipples when they do the brakes, which should be often. For what they cost, and the potential aggro it saves, its a no brainer to my mind....! :whistle:
Customers and the Bill.
A genuine Brembo is over £20 with 2 on a caliper unless you want a Chinese one.
A. Good Tech can get them out.
All mine came out with a little persuasion on the 14 year old Boxster the other month when I made new brake pipes.
 

TimR

Member
Messages
2,656
That does seem a somewhat stark choice...£20 or Chinese cheese...!
I have Brembos on three of my bikes and have replaced the nipples without spending that sort of money.
I will have to ask @Godspeed to see what they use when I enquire about a service kit...
 

nfm

Member
Messages
856
I did a full brake fluid change today. All nipples freed up ok but I had been advance soaking with wd40 for a while; that might make a difference for some.
 

TimR

Member
Messages
2,656
Personally, I was alarmed by how much the bleed nipples needed tightening when I rebuilt my calipers. They wept persistently until I screwed them the f3uk out of sight...! And this will stretch threads, or strip them entirely... and make releasing them harder without a shadow of a doubt.
Ive built brake calipers a few times over the years, most of them Brembo, and never had this issue.
I wonder, when calipers are professionally refurbished, do they inspect/machine the bleed seats....Perhaps mine werent in the best condition?
I was also dissuaded from fitting SS. I ve used SS in a number of calipers that are still good today but the advice I was getting was that they will weep...!
And anyway, SS in aluminium calipers is a recipe for dissimilar metal chemistry to give rise to a problem longer term....