Bleed nipples

[ronk]

I’ve just collected the 335 from the main dealers after a brake fluid change, be told that the bleed nipples are seized In the rear callipers.

I suspect some ham fisted monkey has over tightened it when the fluid was changed two years ago !


I think I will start a flooding with penetrating oil regime asap
Unfortunately they are MSport painted callipers so heat isn’t an option.

 

[TitanTim]

Hi Ron,

That's a coincidence as was just reading a thread on BabyBMW regarding bleed nipple issues on the M Performance brakes.

https://www.babybmw.net/threads/caliper-bleed-nipple-sheared-at-bmw.147228/

Looks like the nipples are tending to seize over time and shear, I'm guessing they just corrode I imagine if over tightened won't help.

Tim.

 

[Rockhopper]

Very common in all types of cars and motorbikes. The nature of brake fluid means it absorbs water - if you don’t clean out the nipple after bleeding you get rust inside, it expands and seizes.

 

[ronk]

They did of course charge me £62 for changing 1/2 the fluid!
As the fluid in the rear is now two years old and known to be hygroscopic, should I just stop worrying and wait until the piston start to seize?

I suspect I will give them a weekly dousing with penetrating oil over the next few months.

 

[Smartbear]

They did of course charge me £62 for changing 1/2 the fluid!
As the fluid in the rear is now two years old and known to be hygroscopic, should I just stop worrying and wait until the piston start to seize?

I suspect I will give them a weekly dousing with penetrating oil over the next few months.

I wouldn’t wait until the brakes seize, braking performance can suffer before then due to moisture in the system
Rob

 

[ronk]

I agree - it goes against the grain for me - I suspect a lot of these “technicians” are not really blessed with hand skills these days!

 

[patriot66]

Hi Ron. I rebuilt my brakes April last year and had to gently 'persuade' the old steel nipples to come out with a blow torch :roll: Replaced all four with stainless steel items and a dab of ant-seize on the threads. Also found some long silicone rubber covers to keep the weather/water at bay

 

[ronk]

That looks good and in normal circumstances I would be doing a similar task but unfortunately I don’t have the mobility to be tackling such a job - I find that quite upsetting when I look back over the years of car maintenance / engine building etc along with all the tools in my garage.

I’m sure the nipples will come out given some persuasion.
They are Msport callipers so loads of heat isn’t an option unfortunately.

 

[Smartbear]

That looks good and in normal circumstances I would be doing a similar task but unfortunately I don’t have the mobility to be tackling such a job - I find that quite upsetting when I look back over the years of car maintenance / engine building etc along with all the tools in my garage.

I’m sure the nipples will come out given some persuasion.
They are Msport callipers so loads of heat isn’t an option unfortunately.

You could always repaint any discolouration due to heat Ron? That’s got to be better than waiting for them to seize
Rob

 

[ronk]

Thinking about the problem, the car is now seven years old and had the brake fluid changed at the required 3, 5 & now 7yrs old

I suspect they were wrongly torqued or inappropriately greased at year five.

Or were they ever removed to change the fluid ?

 

[Rockhopper]

Personally I'd never grease a bleed nipple, there is too much chance of it finding it way into the fluid. After bleeding just use a little bit of kitchen roll to dry the fluid out of the hole and you'll be good. Also don't over tighten as they seat onto a taper.
You don't need to remove them to change fluid, just back off a couple of turns.

 

[ronk]

I suspect over tightening as the main culprit!

 

[TitanTim]

It's always a little disconcerting that something like this won't be covered by any extended warranty as it will be classed as wear and tear/corrosion, I don't now how you would prove any over tightening etc that has caused the issue. Hopefully if its the same garage who have always done the work then they might do some goodwill. Sounds like the standard is replacing the caliper in this scenario.

When I had new front discs and calipers on the Z3 which costs a little shy of 1k it failed its MOT the following year on a twisted fron brake hose, same dealer who did the MOT. Oh hang on you changed the brakes 6 months back, remember

Tim.

 

[ronk]

Ive Just looked at the warranty and it says “excluding seized units “ Well the calliper isn’t seized only the bleed nipple - but I bet they wriggle and ref if to s seizure !

 

[grannyknot]

You might try Speedbleeder nipples, not only do they make bleeding much easier as a one man job but the thread compound prevents water from getting between the nipple and caliper. $7 a piece.