Member Since: 14 Oct 2007
Location: Auckland
Posts: 1264
EPB Screamer - Marshalls Melton Mowbray come up trumps
Out of the blue.....scream, bong and "Park Brake Non-operational" twice (released OK), didn't use for a week and then into Marshalls to sort out. 83k miles, 20k of them mine, out of factory warranty, under extended.
1st phone call, £227 to rectify, failure due to park brake shoes de-laminating. Short discussion stating I found that an unaccetable expalnation and an unacceptable failue in a safety system - and who has heard of critical brake linings de-laminating in the past 20yrs anyway????? Marshalls stated they would contact LRCC and call back...
2nd phone call, LR paying 75% and Marshalls the other 25%...so result! well done Marshalls!!!
Car back same day, all quiet...
This is my second EPB failure in 20k miles, first was a binding RH just after I picked her up. I did mention to Marshalls that my previous D2 had ZERO park brake issues in 192k miles, nothing broke, wore out, fell off or de-laminated and....it worked EVERY time!
There must be a market for a conversion kit that replaces the actuation mechanicals with a std handbrake lever....???Cheers
Simon
30th Jul 2008 2:41 pm
Wex
Member Since: 16 Apr 2007
Location: Knackeragua
Posts: 5173
There is but only at prototype stage
Click image to enlarge
30th Jul 2008 4:06 pm
simonsi
Member Since: 14 Oct 2007
Location: Auckland
Posts: 1264
I forgot, there was a TSB on my D2 handbrake, it required removal of an anti-rattle spring as it was prone to....rattling. When I asked if that wouldn't just make the bit that the anti-rattle spring was supposed to stop rattling, rattle they looked a bit blank.
I spent a couple of hours yesterday with one of the UK's top brake engineers and another couple today with one of Jaguar/ Rover brake chassis engineers, both gave the same reasons for why the system is crap.
It was interesting to note the the type of drum brake used is considered the most powerful type because of the 'double servo effect' of the double ended piston at the top and the floating pivot at the bottom. It was used original by large powerful US cars, as the other types where less effective, but even in the fifties and sixties was known to be imbalanced and liable to cause problems - thats Ford ownership for you -long live TATA
"I know that you believe that you understood what you think I said, but I am not sure you realize that what you read is not what I meant"
30th Jul 2008 4:14 pm
Bodsy Site Sponsor
Member Since: 06 Nov 2006
Location: In the Clubhouse
Posts: 21361
When it's working, it's great, & the Emergency stop feature is pretty good, it's just why does it need adjusting so much & why does it seem to fail more than it should...?
What will the MY10 version do differently to this one? Perhaps just a manual cable to pull on a handle soemwhere....?Bodsys Brake Bible
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30th Jul 2008 4:24 pm
simonsi
Member Since: 14 Oct 2007
Location: Auckland
Posts: 1264
Shiny, that sound's like a single-leading-shoe setup as used on early mini's before it was realised twin-leading-shoe was much more powerful (for service brakes at least) as both shoes are self-servoed into the drum when going forwards.
Of course that is of dubious benefit for a parking brake that should be protecting equally from fwd or reverse movement - and twin-leading requires two cylinders (hydraulic) or actuators (cable) to work - as I'm sure you know.
More importantly what are they doing to fix it?
Just re-read the "floating pivot" bit - that must be what makes the difference over single-leading shoe but yes I can see "floating"="liable to move about unintentionally" Cheers
Simon
30th Jul 2008 4:25 pm
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26775
Well Land Rover should know all of this from experience gained on the Series vehicles. 109 Series 2 onwards have a twin leading shoe setup on the front brakes, the rears are single.
30th Jul 2008 4:30 pm
Bodsy Site Sponsor
Member Since: 06 Nov 2006
Location: In the Clubhouse
Posts: 21361
I didn't think the issue was to do with the twin or single or leading or floating pivit setup, I understand the issue to be more with the servo over-extending it's clutch mechanism and causing the screech. When it's properly adjusted it (seems to be) fine.?Bodsys Brake Bible
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30th Jul 2008 4:35 pm
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26775
I think one of the issues is rapid wearing of the brake components due to binding, dirt ingress, delaminating or whatever else they can think of. Once worn, the actuator over-travels and screams when the clutch slips as it reaches the end of its travel.
Other issues are broken shoe hold down clips which cause the shoes to bind, and I also think the cables are not very water proofed, and dirt makes them sticky and affects the operation.
I also think the correct adjustment process is prolonged and fiddly, and some chaps may be tempted to cut corners and compromise the system.
I'm sure there is more to it, but I do like the simplicity of a lever on a ratchet.
30th Jul 2008 4:42 pm
simonsi
Member Since: 14 Oct 2007
Location: Auckland
Posts: 1264
Gareth wrote:
but I do like the simplicity of a lever on a ratchet.
Hard to think what was wrong with that system in the good old days. Classic case of fixing something that wasn´t broken!Cheers
Just re-read the "floating pivot" bit - that must be what makes the difference over single-leading shoe but yes I can see "floating"="liable to move about unintentionally"
Yes this floating pivot multiplies the servo effect on a single leading shoe, it also as you pointed out allows it to work well as a handbrake ie forwards and backwards which a twin leading shoe is not set up for.
As for doing something about it, I no of nothing but I doubt it as I expect it will cost too much.
If it is any comfort to us, both Jag and Aston are having big problems with the EPB, both work on the disc which as a handbrake is less suited than a drum, unless, and I do not think they have, the system can sense vehicle laden weight and angle, ie a hill. the brake must apply the full clamping at all situation, thus putting a tremendous stain on the system.
On an related subject, I am now being told it's normal to use one set of discs per set of pads. (shame it not one set of calipers as well, I may be able to make some money then. )
"I know that you believe that you understood what you think I said, but I am not sure you realize that what you read is not what I meant"
30th Jul 2008 8:58 pm
simonsi
Member Since: 14 Oct 2007
Location: Auckland
Posts: 1264
shiny moose wrote:
both work on the disc
Hmmm, my old Fiat X1/9 (rally car), used a handbrake working on the std rear disc and pads....worked well enough.Cheers
The guy was getting a bit techie at that point, but as I understood it, it was the combination of electric activation, direct on the caliper, or remote as the Jag system which was not as good, rather than the good old manual cable connected to a lever in the car.
"I know that you believe that you understood what you think I said, but I am not sure you realize that what you read is not what I meant"
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