bambi851 Posted December 29, 2010 Share Posted December 29, 2010 Hi, I've had a look around the forum and not found anything similar, so here goes. Discovery 1996 V8 The brakes have felt pretty weak recently,,, i.e push the pedal pretty far down before anything happens, but they did stop rapidly and straight when it did bite. Last Sunday I was up in the Andes Mountains with it (I'm in Chile and haven't learnt Spanish yet!). So after a long slow and twisty drive up a windy road and gravel path mix(3km) I decided to come back down again. All was fine until I stopped to take some photos. I didn't turn off the engine (possibly hot by now) and let it sit there running while I took photos (a couple of minutes), I got back in the car, put my foot on the brake pedal to put in gear, and my foot went right to the floor. I pumped it a bit and got some pressure and decided to continue. What followed was a scary drive down, lots of pumping the brakes and pulling the handbrake. Sometimes there was a little brake pressure, sometimes there was nothing. When I got to the bottom and found some straight road, it felt like the pressure built up again, but not strong enough to lock up. Any ideas please? Cheers David Quote Link to comment Share on other sites More sharing options...
BogMonster Posted December 29, 2010 Share Posted December 29, 2010 Is there any fluid left in the reservoir? It sounds like fluid loss in which case probably a corroded/burst pipe somewhere. Quote Link to comment Share on other sites More sharing options...
nige90 Posted December 30, 2010 Share Posted December 30, 2010 I'd go for sticking pistons in the front calipers as the symptoms are exactly what I had and a recon of the front brakes cured it. Stripped the calipers and reassembled with new seals and sorted. I even bought proper red rubber grease ! Quote Link to comment Share on other sites More sharing options...
bambi851 Posted December 30, 2010 Author Share Posted December 30, 2010 Is there any fluid left in the reservoir? It sounds like fluid loss in which case probably a corroded/burst pipe somewhere. Sorry, forgot to mention. The reservoir is full. Quote Link to comment Share on other sites More sharing options...
BogMonster Posted December 30, 2010 Share Posted December 30, 2010 OK, not that then. Next question - has it got ABS or not, and if it has can you hear/feel the system operating (chattering noise and pulsing through the pedal) when you are losing brake effect. Quote Link to comment Share on other sites More sharing options...
bambi851 Posted December 30, 2010 Author Share Posted December 30, 2010 OK, not that then. Next question - has it got ABS or not, and if it has can you hear/feel the system operating (chattering noise and pulsing through the pedal) when you are losing brake effect. Yes it has ABS.. although the brakes are not working strong enough to lock up the wheels. When I was on gravel earlier that day I thought I felt and heard the ABS kick in (pulsing and nasty grinding noise). But at the moment the brakes aren't strong enough (and there is no pulsing under normal braking) Thanks for the suggestions. Quote Link to comment Share on other sites More sharing options...
bambi851 Posted December 30, 2010 Author Share Posted December 30, 2010 I'd go for sticking pistons in the front calipers as the symptoms are exactly what I had and a recon of the front brakes cured it. Stripped the calipers and reassembled with new seals and sorted. I even bought proper red rubber grease ! Thanks,, think I'll start from there. Quote Link to comment Share on other sites More sharing options...
disco_al Posted December 30, 2010 Share Posted December 30, 2010 Last Sunday I was up in the Andes Mountains with it my money would be on a tiny bit of air in the system. at these altitudes those air bubbles will expand, giving you the symptoms that you are describing. (i remember reading about a similar problem with a clutch system in one of the LR comics last year - at high altitude they were losing the clutch pedal due to air in the system) Quote Link to comment Share on other sites More sharing options...
BogMonster Posted December 30, 2010 Share Posted December 30, 2010 Yes it has ABS.. although the brakes are not working strong enough to lock up the wheels. When I was on gravel earlier that day I thought I felt and heard the ABS kick in (pulsing and nasty grinding noise). But at the moment the brakes aren't strong enough (and there is no pulsing under normal braking) Thanks for the suggestions. OK. Reason I asked was that a faulty ABS sensor can cause the ABS pump to kick in during normal braking (without locking wheels) which massively reduces the braking effort. I had a similar problem on my 96MY Discovery V8 years ago. Pulled all the ABS fuses and drove it non ABS until I could get a sensor shipped down. But if you cannot feel and hear it operating then it should not be that at fault. Quote Link to comment Share on other sites More sharing options...
bambi851 Posted December 30, 2010 Author Share Posted December 30, 2010 my money would be on a tiny bit of air in the system. at these altitudes those air bubbles will expand, giving you the symptoms that you are describing. (i remember reading about a similar problem with a clutch system in one of the LR comics last year - at high altitude they were losing the clutch pedal due to air in the system) Blimey, never thought of that. It could be why they got a bit better when I came down again. At the top the packet of pringles almost exploded with decompression when I opened it. The brakes aren't feeling to good normally, so I think I will go with bleeding the system and rebuilding the from calipers just incase. Thanks everyone for your advice. David Quote Link to comment Share on other sites More sharing options...
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