mike4444244 Posted July 20, 2009 Share Posted July 20, 2009 Hi all Having some issues getting brakes bled/adjusted 1984 S3 109, all adjusters replaced, all wheel cylinders replaced with gen/oem, master cyl replaced with genuine, Uncle Les's modified piping to put bleed nipple at top. 2.25" shoes on front. Brakes all adjusted so that wheel is locked then backed off slightly. Bled Pedal now travels to floor then goes nice and firm at top of second stroke, theres no air in the system, it feels like first pump is moving pistons, second is moving shoes, but shoes centralised and adjusted as above. Front ( 'S' big union) port on m/cyl is plumbed straight to rear brakes Rear ( 'P' small union) port goes to T piece then front brakes I did previously have these the other way round before Pete noticed the letters, it had exactly the same problem before and swapping appears to have made no difference... The 109 has been stood on someones farm not moving for ages before I bought it but theres plenty of material on the shoes (new on back) and the drums were cleaned up during the overhaul... So... What the french connection UK is going on? is it anything to do with the PDWA thing I threw in the bin? Mike Quote Link to comment Share on other sites More sharing options...
Rich_P Posted July 20, 2009 Share Posted July 20, 2009 No idea! All I can say is that common practice seems to be to clamp all the brake cylinders with G-clamps, and then bleed them. Quote Link to comment Share on other sites More sharing options...
errol209 Posted July 20, 2009 Share Posted July 20, 2009 No idea!All I can say is that common practice seems to be to clamp all the brake cylinders with G-clamps, and then bleed them. Does the pedal feel like it starts moving the cylinder immediately? if not, then whip the cover off the pedal box and adjust the push rod so that it nearly but not quite touches the master cylinder ram when at rest. PDWA? big lumpy thing with two ports on the chassis rail under the master cylinder? It restricts the pressure to the rear wheel cyclinders to make sure the front locks up first. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted July 20, 2009 Share Posted July 20, 2009 Had this before, turned out I put the return springs on the rear shoes the wrong way -easily done as it's not obvious how they *should* go... Quote Link to comment Share on other sites More sharing options...
Guest otchie1 Posted July 20, 2009 Share Posted July 20, 2009 If you are SURE of these two, 1. No air (clamp flexis to make sure) 2. Properly adjusted shoes (wind on to dragging to be sure) Then maybe, 1. leading trailing shoes backwards somewhere (likely) 2. worn out drums Quote Link to comment Share on other sites More sharing options...
FridgeFreezer Posted July 20, 2009 Share Posted July 20, 2009 PDWA? big lumpy thing with two ports on the chassis rail under the master cylinder? It restricts the pressure to the rear wheel cyclinders to make sure the front locks up first. No it doesn't - I suspect it's a Range Rover brake biasing valve you're thinking of. The Series one is a pressure differential warning and is just a shuttle valve that flicks a switch to light a warning light if one brake line loses pressure. Personally I'd have thought the bigger port on the servo should go to the front brakes, what with them doing most of the work, but then ISTR things being a weird way round on Series so who knows. Are you sure you got all the shoes & springs in the correct orientation, it's very easy to get them slightly wrong. Quote Link to comment Share on other sites More sharing options...
TheRecklessEngineer Posted July 21, 2009 Share Posted July 21, 2009 Personally I'd have thought the bigger port on the servo should go to the front brakes, what with them doing most of the work, but then ISTR things being a weird way round on Series so who knows. Are you sure you got all the shoes & springs in the correct orientation, it's very easy to get them slightly wrong. Having just recently done mine, the bigger port should be for the front brakes. It is a 1-in 2-out job. The smaller ports on the other side are for the rear (1-in 1-out) Quote Link to comment Share on other sites More sharing options...
errol209 Posted July 21, 2009 Share Posted July 21, 2009 No it doesn't - I suspect it's a Range Rover brake biasing valve you're thinking of. The Series one is a pressure differential warning and is just a shuttle valve that flicks a switch to light a warning light if one brake line loses pressure. Sorry FridgeFreezer, forgot I was in the Series room! FWIW, my 1988 '90 has the brake biasing valve too. Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted July 21, 2009 Author Share Posted July 21, 2009 Thanks for your help guys, sorry been late replying have spent all night being ill! Errr, ok I'm absolutely certain theres no air in the system, the drums are within spec, pretty sure springs are in correct way round as did one side at a time to make sure but I'd need to check, there are only 2 ports on m/cyl, as above they are marked S and P which we assume is secondary and primary, also exact same problem as before they were swapped, also the shoes are all identical on each axle, ie there doesn't appear to be a leading or trailing shoe, also shoes are adjusted to be on the 'too tight' side just to make sure... I'll whip the drums off this weekend and take some pics Mike Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted July 26, 2009 Author Share Posted July 26, 2009 Ok then, heres some pics of the situation! FRONT MASTER REAR Any thoughts? Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted July 26, 2009 Share Posted July 26, 2009 I know I can answer this for myself in a half hour when I get to the unit, but how many adjusters does the rear brakes have? Pete. Quote Link to comment Share on other sites More sharing options...
western Posted July 26, 2009 Share Posted July 26, 2009 front port of master cylinder should go to the front brakes. Quote Link to comment Share on other sites More sharing options...
Hybrid_From_Hell Posted July 26, 2009 Share Posted July 26, 2009 Yep Bevel off the leading and back edgaes on the new shoes Clamp one hose at a time, see if you can isolate front LH RH vs rear to give you a clue if its the barkes on the axles or Master Cylinder etc Try resettting the shoes so the brakes are locked solid and THEN Bleed the system this last trick was the only way I ever got mine to have a decent pedal then when bleed and only then reset the shoes to normal Nige Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted July 26, 2009 Share Posted July 26, 2009 front port of master cylinder should go to the front brakes. Is there a definate reason for that or is it just convention? As the problem is the same which ever way they are plumbed. Pete. Quote Link to comment Share on other sites More sharing options...
western Posted July 26, 2009 Share Posted July 26, 2009 same master cylinder is used on 110's upto the 300tdi vehicles, IIRC the front piston has a bigger fluid capacity & can create more pressure to service the front brakes requirements. this brake system flaut diagnosis sheet might help [yes, i know it's for defender but faults won't be that much different] Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted July 26, 2009 Author Share Posted July 26, 2009 Hi Pete appears to have fixed it! 2 of the new adjusters weren't adjusting properly, Ralph are you sure the master cyl is the same as the one on my 200 tdi def is completely different, it has 2 ports for the front and 1 for the rear, the series on just has 2 ports? Thanks for all the help guys Mike Quote Link to comment Share on other sites More sharing options...
Guest otchie1 Posted July 26, 2009 Share Posted July 26, 2009 HiPete appears to have fixed it! 2 of the new adjusters weren't adjusting properly, Ralph are you sure the master cyl is the same as the one on my 200 tdi def is completely different, it has 2 ports for the front and 1 for the rear, the series on just has 2 ports? Thanks for all the help guys Mike Also pic 2 & pic 6 looks like you have fitted two leading shoes on the same drum and then two trailing shoes on the same drum but it isn't all that clear Quote Link to comment Share on other sites More sharing options...
Pete Attryde Posted July 27, 2009 Share Posted July 27, 2009 Also pic 2 & pic 6 looks like you have fitted two leading shoes on the same drum and then two trailing shoes on the same drum but it isn't all that clear I wouldn't necessarily disagree with this statement apart from the fact that the pins for the adjusters don't allow the shoes to be fitted any differently. As yet haven't tried the brakes in anger, but the pedal is now correct and consistant. Issue seems to have mainly been caused by a certain manufacturers cheap chocolate adjuster components. Pete. Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted July 27, 2009 Author Share Posted July 27, 2009 Also pic 2 & pic 6 looks like you have fitted two leading shoes on the same drum and then two trailing shoes on the same drum but it isn't all that clear Hi the front shoes (pic 2) are exactly as they were when I got the 109 (no guarantees this is right though) the rear shoes are brand new bought as an axle set, in the box were 4 identical shoes, with no obvious leading or trailing ones Bloody drums I'm off back to my lovely defender with its discs all round.... Mike Quote Link to comment Share on other sites More sharing options...
black ranger Posted August 2, 2009 Share Posted August 2, 2009 Right i know this is going to sound stupid to some people who already know the answer but what is the difference between leading and trailing shoes???? i have just replaced the rear shoes on my 109 and they were identical, the ones i refitted were i guess leading and trailing so i checked the land rover manual and haynes manual and i couldn't get any answers. So which one goes to the front and which one goes to the rear? Simple answers or better still pictures only please. Many thanks Matt Quote Link to comment Share on other sites More sharing options...
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