Nigelw Posted January 27, 2016 Share Posted January 27, 2016 Whilst in for the APK (Dutch MOT) I observed some strange braking behaviour, I am old school and never use the brakes unless I have to, the rollers enabled me to watch as the tester did a series of tests to ascertain brake performance, a sharp stamp for Estop saw a marginal 30% difference in left and right on the front brakes, as he is a friend and knows the vehicle very well we did some experimenting, a gradual pressure up to locking the wheels saw even braking, pretty much 50/50 and Estop straight after saw same result. But why? Fluid is less than a year old as I like to change it every 2yrs. No sign of pulling when I do brake. Any ideas? Quote Link to comment Share on other sites More sharing options...
qwakers Posted January 27, 2016 Share Posted January 27, 2016 sticking caliper. Quote Link to comment Share on other sites More sharing options...
Tanuki Posted January 27, 2016 Share Posted January 27, 2016 Sticking caliper, corroded faces to the discs due to insufficient use: pad-material (partially) detached from the metal backing-plate can also give strange results - I've seen this on low-usage vehicles where rust's got in between the pad-material and the metal backing. Water-immersion and spray from de-icing road-salt don't help! How old/what mileage is the vehicle? When were the pads/discs last replaced?? Quote Link to comment Share on other sites More sharing options...
Nigelw Posted January 27, 2016 Author Share Posted January 27, 2016 1992 D1 so 24yrs old. New discs all round and pads 2yrs ago. Quote Link to comment Share on other sites More sharing options...
Nigelw Posted January 27, 2016 Author Share Posted January 27, 2016 Will add that we off road a lot too, almost every day with farm track that I live on and tracks round our yard. Might be inclined to think sticking caliper and that stainless pistons and resealing might be in order? Quote Link to comment Share on other sites More sharing options...
ejparrott Posted January 27, 2016 Share Posted January 27, 2016 I had the same on an MoT one year. Tester failed it with excesive imbalance. I took it round the block, put it on the rollers, stamped on it, yes massive unevenness. Did it again - his request - didn't apply the pressure so quickly, not far off balanced...that's a pass..... That was my 88 with drum brakes Quote Link to comment Share on other sites More sharing options...
Boydie Posted January 28, 2016 Share Posted January 28, 2016 Nigel, I would definitely advise the S/S pistons with genuine seals - not the ones in a Blue Bag !!! Good brakes are the cheapest form of life insurance I know of Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted January 28, 2016 Share Posted January 28, 2016 Brakes on D1,RRC and Defenders are a real pain when not used regularly. I don't normally cite actual examples but in this case it is very relevant, my dear old Mother potters down the lane in her 1995 D1,rarely gets to more than 40mph and hardly ever goes more than 10 miles away. The brakes on her car are useless and need freeing off or some kind of attention after each winter. My brother has the same year 3.9RRC and uses his for allsorts,mostly long journeys and thecar is often well laden. His car just needs pads as they wear out slowly,never any sticking pads or rusty discs. We always encourage Mother to freewheel and use her brakes as much as possible to exercise them,which is what they need... Quote Link to comment Share on other sites More sharing options...
Sheffield Posted January 28, 2016 Share Posted January 28, 2016 I agree that s/s pistons and proper seals are well worth while. i also use silicon fluid, which does not attract water so much. Quote Link to comment Share on other sites More sharing options...
Souster Posted January 28, 2016 Share Posted January 28, 2016 My dad had similar on his. Rebuilt both front calipers with OEM parts and it sorted it. We were shocked the brakes still worked when stripping down the calipers. The fluid ways were blocked with a wax type gunge, bores full of dirt and rusty looking fluid. Fresh calipers and fluid and it's braking lovely. Quote Link to comment Share on other sites More sharing options...
Boydie Posted January 29, 2016 Share Posted January 29, 2016 The problem with switching to a silicon brake fluid is that you need to replace ALL the existing rubbers in the system, seals and hoses as they can otherwise deteriorate at a rapid rate, the two fluids not being totally compatible. I would stick to DOT 4. Quote Link to comment Share on other sites More sharing options...
Sheffield Posted January 29, 2016 Share Posted January 29, 2016 Our 200 Discovery which we have had for 20 years has had silicon fluid in for most of that time, and has given no brake trouble at all. The 300 we purchased 5 years ago came with a 2 day old MOT and 2 brake pistons rusted solid in their calipers. I refurbished all calipers with s/s pistons, fitted s/s hoses, replaced the steel pipework with copper, and put in silicon fluid. It has had very good brakes since that time. Quote Link to comment Share on other sites More sharing options...
ejparrott Posted January 29, 2016 Share Posted January 29, 2016 You can't generally buy silicone fluid in a hurry either. I've thought about it in the past, but I've stuck to Dot4 in the end Quote Link to comment Share on other sites More sharing options...
teabag Posted January 29, 2016 Share Posted January 29, 2016 The way to tell if it's DOT5 silicone is by the colour, depending on the manufacture and dye used which maybe red, blue or purple-ish, so not the standard white as the rest are. DOT 5.1 has the highest boiling temp and can be used where DOT 4 is recommended, so useful with the vehicle suffered brake fade and is used with performance vehicles. Quote Link to comment Share on other sites More sharing options...
Nigelw Posted January 29, 2016 Author Share Posted January 29, 2016 In real braking there is no seeming loss of efficiency and it pulls up evenly enough, it can still lock all 4 wheels on tarmac too, it is just the oddness from the brake balance on a the test rollers, I was tempted to stick the diff lock in and let it jump out so he had to do a brake "feel" but I am and forever will be of a curious nature. Probably look for a set of calipers to rebuild. Quote Link to comment Share on other sites More sharing options...
Disco RonL Posted January 30, 2016 Share Posted January 30, 2016 please note: a land rover with a Transfer-box (like LT230) cannot (may not) be brake tested on a roller-bank. (as stated in the manual) must be done on brake bank using shifted plates (2 plates on the ground, car driven over it while braking when the wheels are on the plates) My Disco1 breaks well when I progressively press the pedal. Has the same problems as described above when I press it firm/quickly. also inform your APK tester (dutch MOT) that you handbrake is only a parking brake not to be used while driving, otherwise he will also do a test-bank brake test on the handbrake and will damage your car. Quote Link to comment Share on other sites More sharing options...
Boydie Posted January 31, 2016 Share Posted January 31, 2016 Sheffield, in Oz you would get your car rejected with copper brake lines, copper will over time harden and can fracture. Strange how different countries allow different component materials. That said due to corrugations I had a the rear steel line to the drivers side rear fracture due to the vibrations out on the Mulan to balgo road in WA / NT I don't think copper would have lasted as long. Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 31, 2016 Share Posted January 31, 2016 It seems that it's not the ultimate pressure being applied to the pads that is the problem, not the friction developed between pads and disks, but the speed at which the pressure can be applied. I'd be looking closely at the brake lines and hoses. I have Goodridge braided hoses on my 109, and they are truly excellent (the only problem being they should not be clamped when disconnecting a calliper). I think you need to replace your hoses, and would recommend the upgrade. Quote Link to comment Share on other sites More sharing options...
Sheffield Posted January 31, 2016 Share Posted January 31, 2016 I understood good quality copper brake pipes are a copper alloy, so less likely to suffer from work hardening. I have seen many steel pipes rusted through, but never seen a failed copper brake pipe. I suspect it is one of those theoretical problems that does not happen in practice. Or has any one actually seen one broken through work hardening? Quote Link to comment Share on other sites More sharing options...
Snagger Posted January 31, 2016 Share Posted January 31, 2016 Copper-nickel, to be precise. It's only slightly dearer than plain copper, so I have no idea why people go for pure copper... Quote Link to comment Share on other sites More sharing options...
Ally V8 Posted January 31, 2016 Share Posted January 31, 2016 Copper-nickel, to be precise. It's only slightly dearer than plain copper, so I have no idea why people go for pure copper... Its because its softer to bend into shape when fitting.Not a good excuse,but its what I get told when I question why they don't use copper nickel. BTW Boydie, its a bit rich claiming you would be rejected for using copper in Oz - more than half of your country does not even have annual or bi-annual inspections. Some of the rubbish I have seen on the road over there would have been scrapped years ago. Quote Link to comment Share on other sites More sharing options...
Snagger Posted February 3, 2016 Share Posted February 3, 2016 Brake line fracturing is not an issue if they are correctly routed and supported. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted February 3, 2016 Share Posted February 3, 2016 Have to agree,Snagger. Every 12" is a must. Quote Link to comment Share on other sites More sharing options...
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