Very significant brake fade despite very recent brake fluid change..?

derin100

derin100

Active member
So, today is the very first day that I have given my newly acquired 28i a test drive, as I actually just had it delivered here rather than drive it myself.
I gave it quite a spirited drive and braked hard but only about 4 or 5 times. I then experienced very significant brake fade with the pedal almost going to the floor! 😧

This is despite the car having had a major service carried out at a BMW Main-dealer, only 4 weeks and less than 200 miles ago, which included a brake fluid change. This would obviously have been the appropriate fluid that was used. The whole service plus 2 front shocks and rocker-cover gasket came to £3500.

On visual inspection neither the discs nor pads seem particularly worn. After slowing the driving down and not braking hard they ‘came back’. But, you wouldn’t even last a single lap on a small circuit currently!

What could be causing this? TIA
 
It may still have air in the system. Check the level in the reservoir is correct to rule out leaks. Look for any signs of drips inside the wheel which could point to a leak. Take it back as Deepseaskateboard said.
 
Deepseaskateboard said:
I would call BMW and make it their problem. You have paid them £3500. Put it back on them to figure out.
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Thanks….but I didn’t have all that work done. It was the previous owner who I bought the car from a week and a half ago who had the work done 4 weeks ago and that dealership is 200 miles away from me.
 
Something is very very wrong…E89 brakes on the road seldom give problems…could be many things….binding calipers on the discs…due to incorrect fitment of something…if cold and the pedal is firm then air in the system seems unlikely ..but…if air gets into the DSC during bleeding then it needs a special procedure to correctly get the air out of DSC..

If you’re not mechanically minded then a good Indy is your best bet ..
 
I would think it more likely that cheap pads have been put on it at some point - I presume it fell out of the BMW network before now given the age of E89s.
 
Nearly every service (it has been 'over' serviced i.e always ahead of schedule) and nearly all (including the last mjor service) have been at BMW Main-dealers, the others are BMW Specialists.
It's been owned for the last 6 years by the Chair of the '02 Register of the BMW Car Club GB and someone who I have known in the club for over 30 years via the Club. He's actually one of the best known and most respected people in the Club. So, it really has wanted for nothing, as far as I can see from the history and paperwork.
My suspicion is that something wasn't done right at the last service 4 weeks ago at BMW. It was only less than 200 miles ago and if he didn't drive it as hard as I did today, he wouldn't have noticed anything wrong.
I wonder if they haven't bled them properly and there's air in the system.
 
B21 said:
Something is very very wrong…E89 brakes on the road seldom give problems…could be many things….binding calipers on the discs…due to incorrect fitment of something…if cold and the pedal is firm then air in the system seems unlikely ..but…if air gets into the DSC during bleeding then it needs a special procedure to correctly get the air out of DSC..

If you’re not mechanically minded then a good Indy is your best bet ..
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Yep, although I'm pretty handy, if it might get complicated, I'll just leave it to my BMW specialist, who is very good, to sort out.
I'm not driving it anyway, at the moment, as I want to get the timing-chain updated as a preventative measure, along with the water-pump and thermostat, before using it.
So, I'll get the brakes sorted then.
Thanks. 👍🙂
 
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A long pedal is definitely fluid rather than pad related.

I'd suggest another brake fluid bleed. Might be that air is in the system, but I'd start there. I'd also put some higher temp stuff in there like motul rbf600, but... a bit of hard brake use on the road use really shouldn't overheat fluid.

Other than that, I'd inspect all hoses and connections for leaks... its possible something is leaking only when the fluid is hot.
 
brillomaster said:
A long pedal is definitely fluid rather than pad related.

I'd suggest another brake fluid bleed. Might be that air is in the system, but I'd start there. I'd also put some higher temp stuff in there like motul rbf600, but... a bit of hard brake use on the road use really shouldn't overheat fluid.

Other than that, I'd inspect all hoses and connections for leaks... its possible something is leaking only when the fluid is hot.
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Thanks. Yes, it was definitely a ‘long pedal’. I really only braked hard from about 60 mph maybe 4-5 times. So, as you say, it really shouldn’t have overcooked even normal fluid.

Alternatively, I wonder whether a caliper was sticking slightly. I felt the car was pulling slightly to the left initially which is why I did the really hard braking to see if that might free it off. So, that could have ‘warmed’ things up a bit first and then my hard braking just ‘boiled’ the fluid over the edge. The only other car I’ve experienced similar on was on my 840Ci Sport that had been standing a long time and had a sticky caliper.

It’s amazing how quickly it can happen.

The thing against any leakage (I would think?), is that the reservoir is still full to the absolute max?

I’ll get it looked at by my Indie.

Thank you.
 
Could do a brake fluid test... perhaps the last person to bleed it used an old, previously opened bottle that had absorbed a lot of water already... but fresh fluid from a sealed bottle and a proper bleed should help.

Could be a sticky caliper, in which case one wheel would be a lot hotter than the others, which could boil the fluid in that caliper as you say.
 
Unfortunately a lot of people’s idea of a brake fluid change is to suck out what’s in the reservoir, top that up and call it done so you’re left with old fluid mixing with new, plus that’s a sure fire way of getting air in the system if they suck out fluid to below the pipe exits. Anyhoo this sounds like air in the system, if you don’t want to tackle it yourself then ask a good Indy to do a FULL fluid change.
 
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john-e89 said:
Unfortunately a lot of people’s idea of a brake fluid change is to suck out what’s in the reservoir, top that up and call it done so you’re left with old fluid mixing with new, plus that’s a sure fire way of getting air in the system if they suck out fluid to below the pipe exits. Anyhoo this sounds like air in the system, if you don’t want to tackle it yourself then ask a good Indy to do a FULL fluid change.
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As per my original post ……..This done at A BMW MAIN-DEALER and only 4 WEEKS AGO, as part a major service and other works totally in excess of £3500 on behalf of the previous from whom I have just bought the car.

IMG_8074.jpeg
 
brillomaster said:
Could do a brake fluid test... perhaps the last person to bleed it used an old, previously opened bottle that had absorbed a lot of water already... but fresh fluid from a sealed bottle and a proper bleed should help.

Could be a sticky caliper, in which case one wheel would be a lot hotter than the others, which could boil the fluid in that caliper as you say.
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Yes, I’m leaning much more towards the sticky caliper theory and if I had to put money on it, I bet on it being the front left. 👍🏽
 
derin100 said:
As per my original post ……..This done at A BMW MAIN-DEALER and only 4 WEEKS AGO, as part a major service and other works totally in excess of £3500 on behalf of the previous from whom I have just bought the car.

View attachment 285560
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You might be putting too much faith in main dealers there... frequently main dealers do a half arsed job, and charge twice as much.

Find a good indy, they'll sort it properly at a reasonable price.
 
brillomaster said:
You might be putting too much faith in main dealers there... frequently main dealers do a half arsed job, and charge twice as much.

Find a good indy, they'll sort it properly at a reasonable price.
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I agree that BMW Main-dealers can’t always be relied upon and I don’t use them myself (this was the previous owner).
I have used the same excellent Indy, in Lincoln, for the last 9 years and used Indies elsewhere for the last 43 years of unbroken BMW ownership and over 70 BMW cars owned.
 
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I’m not going to be using this particular car until the Spring now. So, it’s not a pressing issue.
Probably in January/February, I’ll take it to my Indy and get this sorted out, as I’m planning to have the timing-chain, water-pump, thermostat and HPFP all replaced as precautionary measures.
 
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