bango690 Posted October 21, 2009 Share Posted October 21, 2009 i am thinking of installing fiddle brakes to the rear of my 90, i have managed to get a rear disced disco axel, how would i go about fixing the second caliper to it? budget is reali tight i think i mite be able to sort out the brakeing system out of existing parts any pictures and information greatley recived (my appoligies if i have posted this in the rong section) matt Quote Link to comment Share on other sites More sharing options...
David_LLAMA4x4 Posted October 21, 2009 Share Posted October 21, 2009 i am thinking of installing fiddle brakes to the rear of my 90, i have managed to get a rear disced disco axel, how would i go about fixing the second caliper to it? budget is reali tight i think i mite be able to sort out the brakeing system out of existing parts any pictures and information greatley recived (my appoligies if i have posted this in the rong section) matt Don't bother with secong calipers - heavy, ugly and unnecessary.... 1/ Buy a CNC fiddle brake assembly from Milners £125? ) OR buy 2 LR series II brake master cylinders and fabricate the levers. 2/ Run the existing brake line to the rear axle into the in port of the cylinder (s ) 3/ Run one hose from each port ( cylindert ) to each back wheel. This might sound obvious but I would suggest the left lever for the left brake!!!! 4/ Bleed the brakes and away you go. Simply pull on whichever lever you want that side wheel to brake on. Just the same a s hydraulic handbrake is plumbed in a rally car but you have one for each wheel. PM, email or call 01938.850382 if I have not made that clear. U have all the hoses, T-pieces connectors etc. in stock if you are struggling to fing them lying around Hope that helsp David Quote Link to comment Share on other sites More sharing options...
bango690 Posted October 21, 2009 Author Share Posted October 21, 2009 Don't bother with secong calipers - heavy, ugly and unnecessary.... 1/ Buy a CNC fiddle brake assembly from Milners £125? ) OR buy 2 LR series II brake master cylinders and fabricate the levers. 2/ Run the existing brake line to the rear axle into the in port of the cylinder (s ) 3/ Run one hose from each port ( cylindert ) to each back wheel. This might sound obvious but I would suggest the left lever for the left brake!!!! 4/ Bleed the brakes and away you go. Simply pull on whichever lever you want that side wheel to brake on. Just the same a s hydraulic handbrake is plumbed in a rally car but you have one for each wheel. PM, email or call 01938.850382 if I have not made that clear. U have all the hoses, T-pieces connectors etc. in stock if you are struggling to fing them lying around Hope that helsp David so i would get away with using the calipers already on the discovery axel? would the fluid not be presurised to the front calipers as well? Quote Link to comment Share on other sites More sharing options...
David_LLAMA4x4 Posted October 21, 2009 Share Posted October 21, 2009 so i would get away with using the calipers already on the discovery axel? would the fluid not be presurised to the front calipers as well? You just use the same calipers as the footbrake uses... The first thing that happens when you press the pedal ( or in this case pull the lever ) is for a little rubber bung to move and seal the port to where the fluid comes in from. This means any pressure exerted on the lever will immediatel;y isolate it from any part of the braking sytem forward of the cylinder. Any more pressure on the lever will send fluid down to the wheel but not up to the front.... A simple process that, as I say, makes the handbrake turn so easy in a Mk2 Escort David Quote Link to comment Share on other sites More sharing options...
bango690 Posted October 21, 2009 Author Share Posted October 21, 2009 You just use the same calipers as the footbrake uses... The first thing that happens when you press the pedal ( or in this case pull the lever ) is for a little rubber bung to move and seal the port to where the fluid comes in from. This means any pressure exerted on the lever will immediatel;y isolate it from any part of the braking sytem forward of the cylinder. Any more pressure on the lever will send fluid down to the wheel but not up to the front.... A simple process that, as I say, makes the handbrake turn so easy in a Mk2 Escort David so i put a t- peice on the brake line of each side? connected to the brake lever like from milners? Quote Link to comment Share on other sites More sharing options...
zim Posted October 22, 2009 Share Posted October 22, 2009 so i put a t- peice on the brake line of each side? connected to the brake lever like from milners? the fiddle brakes go in between your rear callipers and your master cylinder. David made all my brake lines for me, so i have braided pretty much throughout and milner 4x4 is the place to get the fiddle assembly, saves messing around making your own. the taller levers (red tops) in this pic are them : G Quote Link to comment Share on other sites More sharing options...
white90 Posted October 22, 2009 Share Posted October 22, 2009 Standard calipers aren't up to stopping the wheel when power is applied a mate fitted front calipers on to get the stopping power. he welded on extra brackets. Quote Link to comment Share on other sites More sharing options...
trt1617 Posted October 29, 2009 Share Posted October 29, 2009 so in doing this you still have your normal foot brake working on the rear? and is your truck still road legal with this mod done? they might be stupid questions but i have considered doing this to mine and i thought id ask Quote Link to comment Share on other sites More sharing options...
jil6939 Posted October 30, 2009 Share Posted October 30, 2009 Indeed you will...or should i say it would give you more braking if you fit front callipers to the rear. Im not sure of all the types but mine are from a 90/110 with the larger pad area and single line in.I simply cut of the old axle mounting lugs for the rear and ran the bolts through the "new" front callipers into the now cut of lugs, held them in the correct position and welded them back on.DISCLAIMER... i dont actually use my car on the road it is trailered around. As for legal, then im not really all that sure but my car does actually have a current MOT so if it is a problem then its not a large one :ph34r:In fact it makes no difference to my foot brake at all and i still have a separate hand brake?I think there may be a lot of confusion over this and hydraulic hand brakes but im no MOT tester so i dont know. Now i think about it there was something about adding a second line to the rear axle or did i happen to have an old abs axle lying around at the time?!?! Some one help me here.....How many flexi pipes come down to your rear axle by the diff on a standard disco? as you need two to make it work. Quote Link to comment Share on other sites More sharing options...
David_LLAMA4x4 Posted October 30, 2009 Share Posted October 30, 2009 so in doing this you still have your normal foot brake working on the rear? and is your truck still road legal with this mod done? they might be stupid questions but i have considered doing this to mine and i thought id ask The footbrake will indeed work as normal - the fluid passing through the fiddles to the wheels and back through again to the master cylinder with the press / release of the pedal. As long as youstill have a mechanical handbrake seperate to the footbrake sydraulics then it will still be road legal. Re. caliper size mentioned above...., this is not altogether the size of the caliper / pad area. It can alos be down to the bore size of the master cylinder compared to the slave ( caliper ) cylinders. Using a different size master gylinder instead of changing the calipers is often a quicker and easier solution... David Quote Link to comment Share on other sites More sharing options...
jil6939 Posted October 30, 2009 Share Posted October 30, 2009 Why, you are correct Dave.This is perhaps something i should have a look at as when the crawler gear is in i struggle to hold back on the foot brake. Who knows what bigger brake cylinder will go on my disco then? Dave you have seen my car at Gwyns,in fact you made an oil cooler bypass pipe for me, or am i going to have to Quizz Gwyn while he is on holiday Probably only raining on his caravan anyway Quote Link to comment Share on other sites More sharing options...
jil6939 Posted October 30, 2009 Share Posted October 30, 2009 Interesting one about the hand brake being mechanical and it came up on the disco3 forum recently as someone had posed the question regarding the electrickery hand brake on the d3 and how it was mot legal. Shame i cant remember the answer Quote Link to comment Share on other sites More sharing options...
LandyManLuke Posted October 30, 2009 Share Posted October 30, 2009 Who knows what bigger brake cylinder will go on my disco then? You'll want a smaller bore master cylinder, not bigger. Quote Link to comment Share on other sites More sharing options...
jil6939 Posted October 30, 2009 Share Posted October 30, 2009 You'll want a smaller bore master cylinder, not bigger. Lord help me i keep getting worse Quote Link to comment Share on other sites More sharing options...
David_LLAMA4x4 Posted October 31, 2009 Share Posted October 31, 2009 You'll want a smaller bore master cylinder, not bigger. Common size is to drop down to a 5/8" bore from the usual 3/4"...... David Quote Link to comment Share on other sites More sharing options...
sean f Posted October 31, 2009 Share Posted October 31, 2009 Interesting one about the hand brake being mechanical and it came up on the disco3 forum recently as someone had posed the question regarding the electrickery hand brake on the d3 and how it was mot legal. Shame i cant remember the answer From having read the IVA manual as far as I can tell the way the hand brake is kept engaged must be mechanical, so if an electronic solinoid or motor (never looked at a D3) engages something that then latches in place it should be legal. What is not allowed as a handbrake is anything that relies on hydraulic pressure (or I assume electrical power) to KEEP it engaged. I assume this is so if a hydraulic leak did occur the vehicle wouldn't end up rolling down the hill with no brakes at all, I assume if you disconnected the battery on a D3 it won,t roll away, not sure now you could apply the handbrake with a flat battery though?. Quote Link to comment Share on other sites More sharing options...
clbarclay Posted November 3, 2009 Share Posted November 3, 2009 I assume if you disconnected the battery on a D3 it won,t roll away, not sure now you could apply the handbrake with a flat battery though?. I have no experiance of a D3, but they hand brake could be a sprung on type, where the hand brake is normally engadged and is electircally disengaged. A veriation on this would be to have some kind of over centre device, where the electics switch the spring between engaging and disengaging so that if there is a fault while driving along the hand brake ddoesn't suddenly come on. Quote Link to comment Share on other sites More sharing options...
bango690 Posted January 1, 2010 Author Share Posted January 1, 2010 doesnt the disc conversion from x-eng rely on fulid? mayb its just me getting mixed up Quote Link to comment Share on other sites More sharing options...
ThreeSheds Posted January 1, 2010 Share Posted January 1, 2010 doesnt the disc conversion from x-eng rely on fluid? No - it's mechanical: When I first started reading this thread - the bit about extra callipers - I was visualising mechanical callipers, but the hydraulic system described is so much more elegant! Next project I think (once I have got the thing going anyway ) Quote Link to comment Share on other sites More sharing options...
Nobbymogs Posted January 1, 2010 Share Posted January 1, 2010 i had fiddles but tbh they were carp until having a chat with Saley and i then put four pot fronts on the rear ....problem solved Quote Link to comment Share on other sites More sharing options...
simonr Posted January 2, 2010 Share Posted January 2, 2010 It has mostly been covered, but.... If you are using levers such as those from Milners, you either need smaller bore master cylinders or bigger bore calipers to get sufficient force to stop a wheel. For smaller bore master cylinders, have a look at motorcycle brake levers - they are as small as 10mm diameter - giving roughly 6x the pressure compared to a S2 master cylinder for the same lever force. As stated above, 110 front calipers give enough force with the milners levers - then use a brake balancing valve to reduce the pressure from the foot brake such that the front locks up before the rear when you stand on the brakes. A final option is to use S2 masters and pneumatic cylinders to apply enough force. Then you can use a pair of solenoid valves and have push-button fiddle brakes. I know someone who has tried this! Generally you want fiddles to be on or off - nothing inbetween - so a push button is a reasonable way to control them. With 4" bore pistons (you can also modify brake servo diaphrams to provide the same effect) and 100psi, that is about 1000Lbs of force - equivalent to pulling a milners lever with about 150Lbs (75kg). Can you lift 75kg with one hand? i.e. it's quite a lot. If you go down the brake servo route, pressures as low as 30psi can be enough to stop a wheel. You can actually buy these ready made as 'air over hydraulic' brakes for small trucks. Si Quote Link to comment Share on other sites More sharing options...
alex milton-haynes Posted January 2, 2010 Share Posted January 2, 2010 can fiddle brakes be used as a traction aid. as someone who doesnt have arbs if i fitted them, when i got cross axled and the wheel with no weight on it was spinning, could that be locked to transfer drive to the wheel with the traction and weight on it? or is this likely to blow diffs, as i have simex style tyres Quote Link to comment Share on other sites More sharing options...
Night Train Posted January 2, 2010 Share Posted January 2, 2010 can fiddle brakes be used as a traction aid. as someone who doesnt have arbs if i fitted them, when i got cross axled and the wheel with no weight on it was spinning, could that be locked to transfer drive to the wheel with the traction and weight on it? or is this likely to blow diffs, as i have simex style tyres As far as I know that should work if applied gently to a rotating wheel or if the brake was applied before the power. Just need to be quick to release the brake when tracton is found again. Quote Link to comment Share on other sites More sharing options...
robhybrid Posted January 2, 2010 Share Posted January 2, 2010 can fiddle brakes be used as a traction aid. as someone who doesnt have arbs if i fitted them, when i got cross axled and the wheel with no weight on it was spinning, could that be locked to transfer drive to the wheel with the traction and weight on it? or is this likely to blow diffs, as i have simex style tyres Short answer is yes, braking one wheel with a fiddle brake is a crude form of the modern traction control used on many modern vehicles. I may well be using something similar on mu class 3 motor in the near future. But it could possibly blow diffs, break half shafts. It depends entirely on driving style/weight of right foot. Quote Link to comment Share on other sites More sharing options...
iomlt Posted January 3, 2010 Share Posted January 3, 2010 why bother with fiddle brakes when there are the likes of locking diffs or lsd's out there? Quote Link to comment Share on other sites More sharing options...
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