Came back to collect the Land Rover from the local test and was told they took quarter of an hour to suss out the military NATO light switch on the Carawagon, "we knew it worked somehow because you came in with the lights on". They gave up on the switch that said 'Infra Red', must have thought it was one of those quick tan sun beds in the back.
Manuel passed his MOT. I went to the independent garage which does all the MOTs for James Edwards in Chester. You could tell he'd seen a few Land Rovers before, which was reassuring!
Although the brakes work, I was advised that all of the discs are corroded/rusty. I had already seen this myself but wasn't quite sure what to do.
It looks as if the pads are not pressing equally over the discs. ie there is a part of each disc which is not getting any contact with the pad and, therefore, is going rusty.
I was well used to stripping down my Series III's brakes and unseizing the cylinders (or burning oil off the shoes!) but how easy would this be to fix myself? I presume that the calipers/pads are not moving completely freely (?). Could I press the calipers/pads in/out repeatedly to free them up?
Am I on completely the wrong tack here?
I don't want to just replace all the pads and clean up/replace the discs just to find that same happens again in a few thousand miles.
(This is all theoretical until I get my wheel nuts correctly torqued!)
If the pads are very worn the pistons may have pushed further out of their calipers than normal, so after removing the pads, [1] I generally use a g-cramp (more often a bit of wood) to press them back in again, but watch the master cylinder fluid level. If you have another bit of wood that's a tad wider than the pads you can use this for the calipers/pistons to press against, and work the brake pedal so that the piston leaves a mark on the wood, and can give an indication if the pistons are sticking on one side or another .. but it is only an approximation .. ;)
Clean all the accumulated crap from the calipers and 'slidey' bits where the pads reside, I use a handmade scraper and a wire brush. Then use Copaslip (I think that's what it's called, the labels worn off years ago) grease, which is a high temperature anti-seize grease, pasting a very thin smear on all mating / sliding surfaces of the pads and calipers. Don't get any grease at all on the pad friction material, or even within sniffing distance if possible ..
Brute force shouldn't really (though this _is_ a Landrover) be needed unless there's lots of corrosion / crud to get in the way, and usually involves the smallest item, the split pins ...
Have fun .. they're easier to do than S3 brakes ... ;)
[1] Remove ssmall split pin behind the caliper, then pull the pad location/retaining pins, while holding the anti-rattle springs. Pads should now pull out easily .. Replacement, as the saying goes, is a reversal of the removals procedure, but the springs can be fiddly to hold ... It is _much_ easier if you have all new pins/split pins/springs to work with. They come in kits and cost bugger all .. ;)
My Audi Coupe Quattro brakes are MOT tested on the road using a meter attached to a large block of steel that the tester places in the passenger footwell. At a convenient, safe opportunity, he applies the brakes and the meter measures the deceleration. Sorted!
Look for tears in the seals on the piston ends, and replace. Also check that the piston hasn't corroded on the outside.
A friend of mine did his years ago, and the pistons seized in the cylinders, locking the brakes ON (he didn't squeeze the pistons back, fortunately, or he would have had no brakes) He realised there was a problem, but decided the best thing to do was to come and see me - so he drove, with binding brakes, down the M62 for 10 miles. When he got to me, the discs were glowing,the caliper fluid was boiling off, and we had to hose the car !
At the MOT garage I used today, they only have a single axle rolling road so they can't test the brakes of 4WD vehicles. The tester did a very short road test of the brakes. He said he was checking that the ABS light went out, that the vehicle stopped and that there was no veering to the side.
I'm not sure why he mentioned ABS. Although I should think that ABS is not MOT-able, perhaps the warning light would give indication of "something" not being right.
Next time it stops raining, unless I can think of another excuse, I'm going to try to get the wheels off but (as discussed in a previous thread up there ^) I'm expecting to have to take it to a tyre fitter and ask them to correctly torque the wheelnuts.
[Although I've had the Disco for a couple of years, I've used garages for most of the work that the vehicle has needed. I've lost the knack of working on Land Rovers.... although I did spend a couple of hours last week tracking down the Disco's first oil leak! It's leaking where the oil cooler pipe comes out of the oil filter. I was
*astounded* when I noticed a drop of oil underneath ..... I've got so used to having a clean drive!]
Quite possibly siezed pistons and/or caliper slides. Strip & disassemble the calipers. Check that the pistons aren't rusty or pitted and reassemble with new seals (and pistons if required). Clean any rust of the discs with emery cloth (really clean - rust eats brake pads) or if the discs are badly scored get them machined or replace them. Put the calipers back onto the vehicle with new pads, bed them in gently and you're right for another umpteen thousand miles.
Another post mentions pushing the pistons back into the calipers. There is only one "right" way to do this and it's absolutely vital on ABS vehicles as it stops all the collected crap in the caliper being pushed back through the ABS unit and knackering it. Use a brake hose clamp to clamp off the flexible hose, open the bleeder, then force the piston back (the excess fluid will exit through the bleeder). I generally use a large pair of polygrips to force the piston back - if they are tight enough to need a g-cramp then they are partially siezed and should be pulled apart and repaired as above. Once it's all reassembled give the brakes a bleed. Even on non-ABS vehicles this is a good idea as it also keeps the crap from being pushed back to the master cylinder where it does a good job of wearing out the seals.
My 300TDi has been leaking from same place, slowly for 3 years. Just move the gravel about a bit on the drive, was quoted some horrendous cost for the pipe SET from LR, the technician I know ther said "Leave it until you see/smell oil burning" it aint done yet in over 16K miles. Looks worse than it is, collects on fron diff tho a bit. Think of it as keeping the diff rust free :-)
One of the reasons I drive a series is that I don't have to worry about all that ABS stuff. I don't feel any the less secure without it, though I wouldn't mind a set of discs.
One of the benefits of being a (good) mechanic is that you can get along to training courses, read the trade publications and learn from others in the industry. Judging by the some of the comments here about the UK automotive repair industry I should emigrate and set up fixing Solihull's finest.
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