dirtyninety Posted September 29, 2010 Share Posted September 29, 2010 now then, Can someone explain quite what the point in the dual brake pipes on the front of my 93 200tdi disco? Id like to convert to single brake pipes, so what calipers should i use and also what brake cylinder should i use? thanks for any light and the matter Quote Link to comment Share on other sites More sharing options...
Ratty43 Posted September 29, 2010 Share Posted September 29, 2010 Haven't any info on an alternative but dual line brakes are designed to keep working on one circuit if you loose pressure on the other, if yours is the same as mine (same year) it is split so that you will always retain at least one set of pistons on each of the front calipers. I am curious as to why you would wish to remove a safety feature. Also I would have thought that the insurance companies and powers that be would take a pretty dim view of downgrading your braking system Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted September 29, 2010 Share Posted September 29, 2010 Hi Does it matter which pipe goes to which hole on the caliper and does the d/s side need to be the same as the p/s? I was told it did not matter, so I plumbed it in as it looked best to me. I have not had any problems as yet on a 1990 Disco 200 tdi. Just wondering, old age setting in I think. Quote Link to comment Share on other sites More sharing options...
Orgasmic Farmer Posted September 29, 2010 Share Posted September 29, 2010 Well they must have downgraded this safety feature with later models since the 300 TDi only has single port calipers and a 2 port master cylinder. Indeed the early Discos used the same setup as the Range Rover which was quite advanced and, no doubt, quite expensive to produce. I am guess that one of the cost cutting exercises done on the later disco was a swap to the simpler (and cheaper) system as found on 90's.... Quote Link to comment Share on other sites More sharing options...
dirtyninety Posted September 29, 2010 Author Share Posted September 29, 2010 Safety and insurance isnt an issue, im building a discovery challenge truck, so i would like to convert to single port calipers and a 2 port master cylinder, cheers orgasmic farmer!! Quote Link to comment Share on other sites More sharing options...
landmannnn Posted September 29, 2010 Share Posted September 29, 2010 I am just about to plumb mine up like this, planning to put a t-piece near the caliper. Just need to work out which port does what on the master cylinder. Quote Link to comment Share on other sites More sharing options...
dirtyninety Posted September 29, 2010 Author Share Posted September 29, 2010 Do you want me to tell you which port goes to which wheel etc? Quote Link to comment Share on other sites More sharing options...
Range Rover Blues Posted October 4, 2010 Share Posted October 4, 2010 If you are goung to single circuit then the primary goes to the front and the secondary to the back. the 300 Disco had a much cheaper ABS system compared to the RRC hence the single circuit callipers. If you have dual circuit callipers then the top should be the primary IIRC and the bottom is the secondary same as the rear but it's worth checking a manual. I'm not sure if the master cyclinder is the same either and if it isn't there will be a good reason. Performance wise there will be no difference, if you fit single circuti callipers then you could use 130 Defender ones which are bigger. Quote Link to comment Share on other sites More sharing options...
hotspanner Posted October 7, 2010 Share Posted October 7, 2010 Hi dont change your calipers just take a copper pipe from one of your flexible pipe entrys and route it to your top of your caliper where you can remove a bleed nipple and discard it connect copper pipe into this port and job done you will then use the other bleed nipple on the caliper to get rid of air. This does away with the need for two flexible pipes or tee fitting Quote Link to comment Share on other sites More sharing options...
discomark10 Posted April 24, 2013 Share Posted April 24, 2013 Hi dont change your calipers just take a copper pipe from one of your flexible pipe entrys and route it to your top of your caliper where you can remove a bleed nipple and discard it connect copper pipe into this port and job done you will then use the other bleed nipple on the caliper to get rid of air. This does away with the need for two flexible pipes or tee fitting Would this be road legal? Quote Link to comment Share on other sites More sharing options...
Fatboy Posted April 27, 2013 Share Posted April 27, 2013 For the dual circuit to be effective from a safety perspective, I think there needs to be no communication (or very limited) between the two fluid circuits... That would mean that if you eliminate one flexi, you'd have to tee the two lines on the caliper together externally, this both fluid circuits are still fed fluid from the one common supply. By simply removing a bleed nipple and replacing with a fitting that goes on one of the lines which originally fed the caliper the risk is that you may have created a loop with insufficient supply, thus reduced the closing pressure from some of the pistons. Years ago I removed a fluid input line and simply replaced with a bleed nipple, the brakes still worked and I had a good pedal but could lock the rears before the fronts. On my current rebuild I am keeping the dual systems on the calipers with dual braided flexis but fitting a tee at the top onto the single line back to the master cylinder. Quote Link to comment Share on other sites More sharing options...
discomark10 Posted April 27, 2013 Share Posted April 27, 2013 The T idea sounds good.. I was thinking about something like that rather than the bleed nipple idea. what are the thread/size are the brakes lines? Quote Link to comment Share on other sites More sharing options...
Nigelw Posted April 30, 2013 Share Posted April 30, 2013 Sorry to bring this back to life but in looking over my 92' MY Disco the rear brakes are fed off the R/H front caliper line and the L/H has a whole channel all to itself, should this be right? I am looking for a brake line diagram but can't find one on the WWW. Quote Link to comment Share on other sites More sharing options...
Les Brock Posted April 30, 2013 Share Posted April 30, 2013 Quote Link to comment Share on other sites More sharing options...
Nigelw Posted April 30, 2013 Share Posted April 30, 2013 Where is the Hero smiley when you need it! Cheers for that Les. Quote Link to comment Share on other sites More sharing options...
henk Posted May 1, 2013 Share Posted May 1, 2013 @dieseldog I can put you all manuals on a dvd, come and collect it when you bring the wheelnuts Quote Link to comment Share on other sites More sharing options...
Nigelw Posted May 3, 2013 Share Posted May 3, 2013 @dieseldogI can put you all manuals on a dvd, come and collect it when you bring the wheelnuts TOP!!! Henk you have PM Quote Link to comment Share on other sites More sharing options...
Snagger Posted May 12, 2013 Share Posted May 12, 2013 The non-ABS brake systems all have two circuits, but there are tow versions. In the earlier version, the front callipers have two hoses, and the big circuit does half of each front calliper and the rear callipers, while the smaller circuit powers just the other half of each front calliper. Later systems went over to a simplified setup, like on the Defender, where the big circuit did all of the front calliper pistons and the smaller circuit the rear callipers. The contradiction to this is ABS equipped vehicles, which still have twin hose front callipers because each calliper has a piston pair connected to the valve block and the front callipers have a hydrostatic (direct mechanical pedal movement creating hydraulic pressure to the other half, independent of the ABS system - in other words, five circuits (individual ABS controlled to each calliper and then the hydro to both fronts). I suspect early thinking was to ensure that the front brakes always had stopping power by configuring the two circuits the way they did, but in practice the loss of one system tends to make the other pretty ineffective too, as the leaking half permits pedal movement without pressure build up by either MC piston to activate the fault-free circuit, leading to the adoption of the simpler system split front/rear. Quote Link to comment Share on other sites More sharing options...
western Posted May 12, 2013 Share Posted May 12, 2013 there are 2 different split brake circuits used on various vehicles [not just LR's] a I - I circuit has the front & rear as seperate but when working with no circuit failure they work as one circuit , if the fronts fail then the rears can still slow/stop the vehicle & vice versa the other type is a H - I circuit, so one is front & rear brakes [& in normal no failure use] if the H circuit fails the I circuit still works & vice versa Quote Link to comment Share on other sites More sharing options...
Sheffield Posted May 13, 2013 Share Posted May 13, 2013 I have a 1996 300TDI auto (not ABS) with the single front pipe arrangement, which needs new discs and pistons, and I also have to hand all the parts for a dual front pipe system with vented discs (almost new) from a 1991 RRC. I have thought about using these to change the Discovery to dual pipe vented brakes. Is this a good idea, please, or a bad one? Quote Link to comment Share on other sites More sharing options...
Aragorn Posted May 15, 2013 Share Posted May 15, 2013 I suspect early thinking was to ensure that the front brakes always had stopping power by configuring the two circuits the way they did, but in practice the loss of one system tends to make the other pretty ineffective too, as the leaking half permits pedal movement without pressure build up by either MC piston to activate the fault-free circuit, leading to the adoption of the simpler system split front/rear. The idea in any split braking system, is that the piston inside the MC bottoms out on the leaking side, then you build pressure as normal on the second cylinder. That means you end up with a much longer pedal, and half the braking effort, but still have working brakes. I've been lucky never to have brakes fail, but my mum once drove a Mk5 transit home from the supermarket with (unbeknowst to her) a burst front brake hose. She got home and told me the pedal had "gone a bit funny" but it otherwise seemed to stop ok Pic of MC internals and what happens when you blow out one line: You can see the yellow piston has bottomed out against the end of the housing, allowing the grey piston to operate normally. there are 2 different split brake circuits used on various vehicles [not just LR's] a I - I circuit has the front & rear as seperate but when working with no circuit failure they work as one circuit , if the fronts fail then the rears can still slow/stop the vehicle & vice versa the other type is a H - I circuit, so one is front & rear brakes [& in normal no failure use] if the H circuit fails the I circuit still works & vice versa Many cars also use a diagonal split. Two port master cylinder with a constant bore, each port running one front and the diagonally opposite rear. Quote Link to comment Share on other sites More sharing options...
Snagger Posted May 18, 2013 Share Posted May 18, 2013 The diagonal split was common a while ago, but I think most modern cars have symmetrical systems to make sure the car pulls up straight under braking. I can see the logic behind the split master cylinder, but I found on my SIIIs that in practice it didn't seem to work - the travel required to pressurise the serviceable side was just too long (and the brake systems were well cared for, not worn, leaking and mal-adjusted). It might work better on disc brake systems, though, as they have less fluid transfer. Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted November 16, 2013 Share Posted November 16, 2013 Hi and appoligies for poking this back to life. Can't beleive I am asking this again 3 years on. Last time I just plumbed it in as I thought it looked best. :-( It went through MOT twice ok but now I have the calipers of for a refurb and I would really like to know how to do it "right". So can anyone lead me astray and explain the proceedure. ;-) Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted November 17, 2013 Share Posted November 17, 2013 I had searched this topic and was reading it over and I thought one of the threads was very similar to what I was asking. When I scrolled over and seen it was mine :$ form 3 years past. Must say in my defence I was using a mobile to read it. :-D Seriously can anyone help on this matter. A diagram would be most helpful. By the way mine does not have abs. I suppose it will have something todo with the brake pipes coming out of the master cylinder. Quote Link to comment Share on other sites More sharing options...
bushwhacker Posted November 18, 2013 Share Posted November 18, 2013 Anyone any info at all on the correct way to bleed the dual front brake pipes with NO ABS and solid disks on an early Discovery. Quote Link to comment Share on other sites More sharing options...
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