seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
  
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| Advice on front brakes binding / applying issue. Not ABS/DSC |
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Hello, my front brakes are apparently binding after 10-15 minutes of driving.
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- After 10 or so minutes of driving, pedal begins to firm up
- Noticeable effort from engine to maintain speed
- Braking increase until pedal response is quite solid and car will not roll off at idle (in drive) on flat ground.
- If accelerating through it, braking pressure just increases until it’s undriveable.
- DSC is switched off
- Doesn’t feel like anything close to ABS/HDC/DSC applying
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Work that’s been relatively recently carried out; full brake bleed, new discs / pads, new master cylinder.
- In effort to diagnose, I’ve checked slides. They’re fine, lubricated with silicon paste.
- In testing with pads removed (carefully) applying brakes, one piston pushes out before other. Second piston only pushes out once first piston is mechanically stopped. (I feel this may be normal though).
- I’ve applied silicon paste liberally under the bellows/rubber boot around each piston but not passed the inner seal.
- I am assuming one or both pistons are binding inside the calliper, and after a time of light application while driving, they’re heating up and expanding/binding more stopping them from releasing at all after brakes applied.
My next step is to source new pistons / seals and rebuild calibres but I wanted to post here to see if it could possible be anything else causing this, such as vacuum pump/brake booster.
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 30th Oct 2023 10:25 am |
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Admirable
Member Since: 19 Jul 2015
Location: Fife
Posts: 1038
 
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Have you checked the servo for oil deposits?
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| 30th Oct 2023 10:43 am |
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Gareth
Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26774
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Are you sure it’s the front brakes and not the park brake? I guess you would notice hot wheels on the offending corner.
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| 30th Oct 2023 2:10 pm |
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seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
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Thanks Gareth, yes I'm positive it's front as they are noticeably hotter than rear; front left more so than front right.
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| 31st Oct 2023 12:00 am |
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seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
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Admirable wrote:Have you checked the servo for oil deposits?
No I have not yet. Though I did when replaced the master cylinder a couple of months back and appeared fine.
Why I have not this time is I thought if the brake booster was bad then the brakes would be struggling to apply rather than locking on. Is that correct?
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| 31st Oct 2023 12:03 am |
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loanrangie
Member Since: 18 Jun 2017
Location: Melbourne
Posts: 700
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That is usually the case but its possible that you have too much vacuum.
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| 31st Oct 2023 4:57 am |
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Farmer Chalk
Member Since: 06 Mar 2013
Location: Independent Republic of Kentishshire.
Posts: 4195
 
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The symptoms you describe are exactly the same as I had and it was a binding piston in the calliper. Would drive fairly perfectly for ten minutes and the heat expanded everything until the wheel wanted to lock.. once cooled you could repeat the cycle all over again…
Dependant on price and availability where you are, I found it easier and less grief by putting on a new calliper..
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| 31st Oct 2023 7:33 am |
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Nasher
Member Since: 07 Mar 2009
Location: Clanfield, North of Pompey - UK
Posts: 2813
 
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I spent hours on my D3 trying to get the front Caliper pistons to move freely.
They looked fine with no corrosion, but once they were hot they just didn't retract that small amount when the pedal was released.
I assumed it was corrosion in the seal groove pushing the seal against the piston too tightly, which is an issue I've had on nearly every motorcycle I've ever owned that I've used all year round.
I investigated a seal replacement kit to rebuild them, but found that complete Calipers from the likes of Britpart were so cheap it wasn't worth the hassle of rebuilding the old ones.
It must be @6yrs ago now but they were @£65 a side. Heaven doesn't want me, and hell is afraid I'll take over.
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| 31st Oct 2023 7:48 am |
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seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
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Farmer Chalk wrote:The symptoms you describe are exactly the same as I had and it was a binding piston in the calliper. Would drive fairly perfectly for ten minutes and the heat expanded everything until the wheel wanted to lock.. once cooled you could repeat the cycle all over again…
Dependant on price and availability where you are, I found it easier and less grief by putting on a new calliper..
Thanks mate, that is great to know.
I've done some initial googling trying to find new calipers today and couldn't find any, going to check with my lr parts specialist tomorrow.
After a bit of thought I decided today to take to a local indie mechanic here in Hobart who also has a very nice D3. I'll hear back from him in the next day or so but will pass on the information from here too.
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| 31st Oct 2023 9:12 am |
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seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
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Nasher wrote:I spent hours on my D3 trying to get the front Caliper pistons to move freely.
They looked fine with no corrosion, but once they were hot they just didn't retract that small amount when the pedal was released.
I assumed it was corrosion in the seal groove pushing the seal against the piston too tightly, which is an issue I've had on nearly every motorcycle I've ever owned that I've used all year round.
I investigated a seal replacement kit to rebuild them, but found that complete Calipers from the likes of Britpart were so cheap it wasn't worth the hassle of rebuilding the old ones.
It must be @6yrs ago now but they were @£65 a side.
Thanks mate, very helpful to know the exact same symptoms have been had by others.
As above I decided to take it to my local indie today, but will pass on this information and might order some calipers if I can get hold of my parts supplier tomorrow.
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| 31st Oct 2023 9:14 am |
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loanrangie
Member Since: 18 Jun 2017
Location: Melbourne
Posts: 700
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seacutter wrote:Farmer Chalk wrote:The symptoms you describe are exactly the same as I had and it was a binding piston in the calliper. Would drive fairly perfectly for ten minutes and the heat expanded everything until the wheel wanted to lock.. once cooled you could repeat the cycle all over again…
Dependant on price and availability where you are, I found it easier and less grief by putting on a new calliper..
Thanks mate, that is great to know.
I've done some initial googling trying to find new calipers today and couldn't find any, going to check with my lr parts specialist tomorrow.
After a bit of thought I decided today to take to a local indie mechanic here in Hobart who also has a very nice D3. I'll hear back from him in the next day or so but will pass on the information from here too.
Justin Cooper by any chance ?
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| 31st Oct 2023 10:44 pm |
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seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
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loanrangie wrote:Justin Cooper by any chance ?
Hi mate, no not this time. Phil Parnell of Parnell Mechanical. I haven't met Justin yet but obviously reputation is sensational, he's just a bit further away from me than Phil but no doubt I'll meet him one day.
I have to say Phil was fantastic to deal with though, and I would not of found the issue myself (will post shortly). His workshop was also like a disco lovers heaven. There was one D4 3.0 up on the hoist with body off; recoe'd 3.0 on stand being built out, plus his own D3 is an absolute weapon on 33's and fully kitted out. He had a 2.7 there too and talked me through the fuel pump belt which I need to do soon, that was awesome.
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| 2nd Nov 2023 11:58 pm |
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seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
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| Solved: Upper slide pin on lhs was slightly bent |
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Thank you all for your replies and advice.
Phil discovered that the upper slide pin on the left hand front caliper was slightly bent. (like imperceptibly small bend). I put a 6" rule on it and it was maybe 0.5mm if that.
He ordered some new genuine slides for me and I fitted them last night, test drove for half an hour or so and had no issues with braking.
I have got no idea whatsoever how the slide got bent in the first place. The last work I did to the car before this was (brake discs / pads / half shafts / front hubs) but that was some months ago. I can only imagine I've somehow bent the slide during that work and it's taken a couple of months for it to become an issue.
I've just replaced both front lower arms, front left lower rear bush was toast for a good three or four weeks and the braking issue first appeared during that time. That's the only other possible reason I can think of ie. the lower control arm somehow cause it to bend when going over a bump or something, but that's doubtful.
Whatever the cause, my next step was to order new calipers which aren't too cheap in Aus to be honest, so I've save $500 odd bucks there thanks to Phil identifying the slide issue.
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| 3rd Nov 2023 12:05 am |
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seacutter
Member Since: 07 Oct 2021
Location: Lauderdale
Posts: 17
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Update, unfortunately after a couple of drives today the issue remains. Have ordered new calipers.
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| 3rd Nov 2023 6:26 am |
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KPTV8
Member Since: 05 Feb 2012
Location: Itinerant !! (Scotland/Donegal)
Posts: 187
 
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I had similar behaviour a few years back (2006 D3), car was always fine on local driving, no excess heat, but on sustained high speeds on m'way the FNS wheel would heat-up and start to bind, had to stop for an hour to let it all cool then resume journey.
LOTS of brake dust around FNS wheel.
It took TWO CONSECUTIVE caliper changes to clear that fault, I was wary of the situation for a few months but it did genuinely settle down. Maybe a bad batch of calipers out there ? I'm sure they weren't sourced from JLR but can't remember, was about three years ago.
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| 3rd Nov 2023 11:47 am |
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