BSF Posted March 18, 2014 Share Posted March 18, 2014 I have been trying to get the brakes bled on my Series 2B rebuild for three weeks; nothing seems to sort it out. The best I can get is a little bit of pressure with the pedal near the floor. Pumping pedal gives good pressure, but still spongy. First, a few details. Front brakes are Defender discs, rear brakes Land Rover Drums (original with new W/Cyls). Master cylinder is Srs 2 B standard (a new one), it is the type with a big nut on the end. Servo is a new Lockheed remote, and yes it is correctly mounted facing up at 25 degrees and the control valve 45 degrees below horizontal. Servo mounted behind cab on right side. System goes from M/Cyl to tee piece by servo. One goes to back brakes, other to servo. Output from servo goes forward to chassis above front right wheel with tee piece to disc via a short pipe and a flexible and via longer pipe to left wheel. All pipework is new. Bleeding method Gunston Easybleed. sometimes with a bit of help from pedal. Cannot get the air out. By selectively blanking out front wheels, backs work fine. By connecting individual front wheels to M/Cylinder, no problem. Blanking output from servo no problem, good pressure. Connecting complete system up, but by-passing servo makes no difference. Help! I am now buying brake fluid by the gallon! Anyone got any ideas? Quote Link to comment Share on other sites More sharing options...
discomikey Posted March 18, 2014 Share Posted March 18, 2014 have you tried using your eazibleed to reverse bleed the fronts? i.e. push the fluid in at the nipple, the air wants to go up so why not help it Quote Link to comment Share on other sites More sharing options...
BSF Posted March 18, 2014 Author Share Posted March 18, 2014 Yes, I even tried that, although I did it with a syphon. I will try it again with the eazybleed. Thanks Quote Link to comment Share on other sites More sharing options...
discomikey Posted March 19, 2014 Share Posted March 19, 2014 let us know how you get on Quote Link to comment Share on other sites More sharing options...
Phil Hancock Posted March 19, 2014 Share Posted March 19, 2014 Is the master cylinder mounted at an angle the same as on a normal control as air gets trapped in the master end cap if the vehicle is on the level or nose down, you need nose up to let the air out. Quote Link to comment Share on other sites More sharing options...
Tanuki Posted March 19, 2014 Share Posted March 19, 2014 I remember a few decades back having the same sort of problem on a 6-cylinder 109: my mistake had been to do the shoe-adjustments up to 'just not quite dragging' before the bleeding. Winding the adjusters back to minimum on all four corners meant there was then no 'dead' airspace in the wheel-cylinders that the shoe-return-springs couldn't push the pistons back into and so squeeze the air from. Once I realised this and backed off the adjusters, bleeding was easy. But to this day I hate Series drum-brakes with a vengeance! Quote Link to comment Share on other sites More sharing options...
BSF Posted March 20, 2014 Author Share Posted March 20, 2014 So, today I dropped the back down until it is just resting on the brake drums, the front wheels are about 18 inches off the ground, so a very nose up attitude. bled it out to no bubbles same problem, air somewhere. Then I blanked out the back brakes, no change. I then blanked the whole system off downstream of the servo and got a good solid brake pedal indicating that everything up to and including the servo has no air. I reconnected the servo output and blanked off both lines from the front Tee to the wheels, still a good solid pedal. Reconnected pipe to right wheel and blanked off at the downstream end of the flexible, still good solid pedal. Connected up to right calliper, pedal spongy and nearly down to the floor. Then I took the calliper off and tried bleeding at every possible angle. No air came out and no improvement when refitted. It must be in the calliper, but what? If it was a drum brake it could be a badly fitting shoe, but these are new Defender callipers and pads. Seriously thinking of taking up gardening or golf. Quote Link to comment Share on other sites More sharing options...
discomikey Posted March 20, 2014 Share Posted March 20, 2014 you know the next question, what colour box did it come in? are the seals okay? i know in theorey unless it was a faulty seal it shouldnt be spongy no matter who made it, although just thinking "outside the blue box" the quality of the casting inside could maybe "Catch" the air although i am just speculating here and as always, the answer is nearly always much simpler than that. out of interest, what if you swapped your known good caliper (or even easier a known OK for these purposes old one) onto that side, and blank other side off, what does the pedal feel like as this will determine for sure wether its a faulty caliper or not. just my 2p Quote Link to comment Share on other sites More sharing options...
BSF Posted March 20, 2014 Author Share Posted March 20, 2014 They were part of a kit from Hetstee and all his stuff is pretty high quality. Unfortunately there isn't an old one as the previous front brakes were drums. I have blanked both the back brakes and the other calliper off. the problem is the same on the other side as well. I just can't see what can cause it. Quote Link to comment Share on other sites More sharing options...
discomikey Posted March 20, 2014 Share Posted March 20, 2014 have you contacted heystee they may be able to help but does sound a bit odd Quote Link to comment Share on other sites More sharing options...
deep Posted March 21, 2014 Share Posted March 21, 2014 I remember a few decades back having the same sort of problem on a 6-cylinder 109: my mistake had been to do the shoe-adjustments up to 'just not quite dragging' before the bleeding. Winding the adjusters back to minimum on all four corners meant there was then no 'dead' airspace in the wheel-cylinders that the shoe-return-springs couldn't push the pistons back into and so squeeze the air from. Once I realised this and backed off the adjusters, bleeding was easy. But to this day I hate Series drum-brakes with a vengeance! This seems to be the best system on any drum brake Land Rover. As well as the reason given by Tanuki, it also gives a big rush of fluid at each bleed nipple, which is very effective at shifting air. I'd try that before giving up. Of course, you've only got two drums but it should still be effective. I actually would have thought you'd have had the opposite problem, because disc pads move very little, compared to shoes. I might have expected a wooden feeling at the pedal. Not that I am an expert. My Stage One V8 is doing weirdly inconsistent things with its brakes that have me scratching my head a little... Quote Link to comment Share on other sites More sharing options...
BSF Posted March 25, 2014 Author Share Posted March 25, 2014 Partial success! After a suggestion from the guy who does my MOTs, I made 4 dummy "pads" out of some bits of steel about the same thickness as the backing plate on the pads and put them in the calliper. Then pumped the brakes to bring the pistons as far out of the calliper as was safe without them actually falling out. I then left them for 24 hours. The brake pedal was then held partially down with a piece of wood (to stop fluid moving in the system) and each calliper bled by levering the pistons back to fully retracted position. The pads were then replaced. The pedal is not completely solid, but it is much better and probably useable. Quote Link to comment Share on other sites More sharing options...
discomikey Posted March 25, 2014 Share Posted March 25, 2014 have you pumped the pedal solid and held overnight too? that helps loads sometimes Quote Link to comment Share on other sites More sharing options...
qwakers Posted March 25, 2014 Share Posted March 25, 2014 thats a good one^^^ i use this method on motorbikes all the time. i once aimed my gopro camera at the reservoir overnight and sped it up to watch it back, and the amount of bubbles that appear is amazing and that is after i was sure i had got all the air out..... Quote Link to comment Share on other sites More sharing options...
Boydie Posted March 26, 2014 Share Posted March 26, 2014 Try this method. Get a good quality gearbox oil pump, fill it with brake fluid and clamp the hose to the furthest brake nipple from the master cylinder, slacken off the union at the MC and connect a hose from it to a clean bottle filled to above the hose level and then with the oil pump pump brake fluid through, carry out the same action working your way to closest brake to the MC. Its messy but it works Quote Link to comment Share on other sites More sharing options...
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