if it's been left standing for a while, the brakes behave very much like ones that have got a thorough soaking; lots of pedal effort and not much stopping. This isn't AFAICS a lack of vacuum. After using the brakes a few times, they work normally, hence I don't suspect the vacuum.
the symptoms are also similar to pad fade on overheated discs, but this happens when the brakes are cold.
the pads only have about 3-4mm left, so I reckon I'll replace 'em, anyway, but any ideas out there?
discs are clean and flat and correct thickness, BTW, and calipers all look OK too.
If I leave Piglet for 2 weeks he's the same. Now I know I simply blatt him up a local straight road with no traffic and slam the anchors on a few times until the ABS wakes up ;-)
Mine was stood for about 8 weeks and was really bad for the first mile until I wore all the surface rust off the disks. From the symptoms it does sound as though there's something on the friction surfaces.
Austin Shackles vaguely muttered something like ...
I'd hazard a guess at air in the system .. 'thin' pads might use a fair amount of fluid to extend the brake pistons, so unless the brake reservoir was really full, may have drawn air in at some point. The reservoir is generally big enough to cope with pad wear though ...
On or around Fri, 13 Aug 2004 10:57:14 +0100, Tim Hobbs enlightened us thusly:
pedal feels OK. It really does feel a lot like not enough friction - exactly like you get if they get soaked or if you've overheated the pads/discs enough to fade 'em. Never actually done that on a LR, but did it once on an Audi 80. In that case the discs were old and thin.
Few possibilities, You could have some rust in the cylinder bores if the fluid was old, leading to rough operating for a bit - check the discs arent running hot after a couple of miles without using the brakes at all . If so rebuild the cyls Most likely to be rust on the discs, remember powdered rust can be a relatively good lubricant between the pads and discs until its all worn off. There will be quite a lot of rust on the discs after more than a week or so standing especially given the rain/humidity of late.
Hrm. I've done it in the Disco. I was doing about 90mph on a clear road [1] on the way to a shout and had to brake for the roundabout. Luckily I was already using engine braking a bit, but there was a sudden lurch in my stomach when I realised what was happenning. That's quite a steep hill.
On or around Sat, 14 Aug 2004 22:29:17 +0100, Aled enlightened us thusly:
you need vented discs.
remember a story in Trucking International a few years back, just after someone had demolished that pub at the bottom of the hill in the Cotswolds (Dursley? summat like that).
someone wrote in with the very valid comment that it's not the road, but the drivers, that are dangerous. He then went on to describe the incident he'd seen recently a the "silly roundabout" in Hemel Hempstead, (aka "ring junction" - he was proceeding sensibly down the hill approaching same, when he was overtaken by an artic doing about 60. As the artic reached the bottom of the hill and the first mini-roundabout, the driver hit the brakes and locked up all the trailer wheels, with a huge cloud of smoke, swung around the junction with little reduction in speed, the trailer heeling over like a racing yacht, and charged off the other side. When the narrator got to the bottom, there were black skidmarks extending from before the first mini-roundabout to past the second one, and there was a pal of tyre smoking drifting in the air. The other driver had crossed about 4 give-way lines, at such as speed that there was no possible way he could have given way.
Now, someone else has said that to me. Can I just replace the standard LR ones? What kind of cost impact am I looking at? Also, are there any caveats with them?
Absolutely. I most certainly would not do those speeds on that road in traffic. Fortunately not only was it quiet, but I was starting to break early enough that I didn't overshoot anyway, just left a nasty brown stain, that's all. :)
Er, yes. That's not good. I hope he either got nobbled for that, or it scared the willies out of him to the point where he learned his lesson.
I know a number of lorry drivers and it's a shame that they're often under such pressure to get a job done within a time limit that is totally unrealistic. Most of the guys I know have had "Oh shit" moments that have brought things into perspective and as a result are now much happier, and calmer drivers, choosing jobs which don't require super- human feats fo driving endurance.
Vented disks can, reputedly, fill with mud when offroading.
Conversion is easy. Either replace the calipers with vented ones or by a conversion kit to space out the existing ones. I went for the latter - about £100.
If you are replacing the calipers, 110 ones are said to be the way to go...
If you want really good Disco brakes, talk to David at Llama. I've got his cross-drilled vented disks up front with kevlar pads and stainless hoses. Brake performance is unrecognisable after the conversion.
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