kennymac Posted June 2, 2008 Share Posted June 2, 2008 Hi folks, Hoping that someone can help me. It seems the master cylinder has gone on my Landy, (it won't keep a pedal, even when I clamp all the flexi pipes down). Does anyone know where there is a pictorial guide to replacing one? The haynes vague has left me a bit confused, hoping someone knows a site where its detailed. Thanks in advance Ken Quote Link to comment Share on other sites More sharing options...
western Posted June 2, 2008 Share Posted June 2, 2008 it's a straight forward job, no special tools except for a brake bleeding kit once it's all fitted. Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 3, 2008 Share Posted June 3, 2008 Disconnect the two brake lines from the master cylinder (10mm or 11mm spanner). Fluid will start to leak out of the master immediately, so be prepared for this. Carefully move the two pipes out of the way and then undo the two retaining nuts that secure the master to the servo unit. The master cylinder can then be removed. Fitting the new master is the reverse of removal. Attach it to the servo, reattach the two brake pipes in the same position as before (this is important) Fill the master and bleed the brakes. You may find that because the new master is 'dry' it might not want to bleed. If this happens, you will need to disconnect the pipes again, get someone on the pedal, then get them to press it, put your finger over one of the holes, then release, take your finger off, press, put your finger back on, release, and so-on until fluid squirts out of the hole. Replace the pipe and then do the same again on the second hole. Once you have the the pipes back on, bleed the system in the usual way. Brake fluid will strip paint off, so be careful about splashes. Les. Quote Link to comment Share on other sites More sharing options...
muzaz Posted June 3, 2008 Share Posted June 3, 2008 Just to add a little thing that might save you time, prepare a can with some brake fluid before you remove the pipes, as soon as you take them off, put them in the can submersed in oil (to prevent air getting in). Replace the master as Les said, and bleed it before you put the pipes back (as Les said), then put the pipes back again, if youre quick enough you might even get away without bleeding the whole system...but for safety's sake bleed it all the same, doing it this way should prevent a lot of air getting it the system.. My 2cent worth Quote Link to comment Share on other sites More sharing options...
silvio Posted June 3, 2008 Share Posted June 3, 2008 Try "reverse bleeding", I used this method when I last changed both master and slave, and so the system was totally empty, but worked a treat! Basically you only need a large plastic syringe (between 60 and 100cc) with a large nozzle (here in Italy they call them "catheter" nozzle) and a short length of hose. Fill syringe with dot 4, undo the bleed nipple on slave cylinder and connect the syringe via the hose; inject the fluid and when you're done close the bleed nipple before removing the hose and syringe. With 2 or 3 strokes you should be OK, fluid will emerge in the master reservoir and will carry upwards every air bubble. No costly appliances, no waste of fluid, no mess. If you can get someone checking the master reservoir, all the better and faster! Sorry, I now realize this concerned BRAKE master, not CLUTCH master, disregard the above .... Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted June 3, 2008 Share Posted June 3, 2008 Well as the original poster didn't specify, you can hardly be a mind reader Silvio. But your method should work for brakes as well, I reckon. Personally when bleeding the brakes on a Defender or Disco, I just undo the nipple and let gravity do the rest. Just wash off the mess with water. And Defender clutches can be bled by just jumping up and down about 20 or so times on the clutch pedal. As the master cylinders only last 5 minutes you have to get used to doing this Quote Link to comment Share on other sites More sharing options...
silvio Posted June 3, 2008 Share Posted June 3, 2008 And Defender clutches can be bled by just jumping up and down about 20 or so times on the clutch pedal. As the master cylinders only last 5 minutes you have to get used to doing this ...saying that you need a couple of minutes to complete the 20 or so jumps on the pedal , you are left with a master cylinder useful life of about 3 minutes... Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted June 3, 2008 Share Posted June 3, 2008 Those Series things are completely useless. (As you know). Even 3 minutes is better than nothing Even the stainless steel resleeved ones we use still give problems. But not so often. Quote Link to comment Share on other sites More sharing options...
kennymac Posted June 9, 2008 Author Share Posted June 9, 2008 Hello again folks, thanks for all the advice. One more thing before I go off and start purchasing, how do I know if the servo unit is away also, not just the master brake cylinder, sorry if this is a daft question! cheers Ken Quote Link to comment Share on other sites More sharing options...
Les Henson Posted June 9, 2008 Share Posted June 9, 2008 Pump the brake pedal, and with your foot still on it, start the engine. The pedal should drop about an inch and then once again be solid. Alternatively - if the engine has been off for a while - pull the vaccuum pipe off it and you should hear a hiss as the vaccuum is equalised. Les. Quote Link to comment Share on other sites More sharing options...
kennymac Posted June 20, 2008 Author Share Posted June 20, 2008 And so it goes on... So, as Les said, it was indeed a piece of cake to change the master brake cylinder, however, I'm having significant problems with bleeding the brakes now. I seem to have an airlock, and I've tried manually bleeding, and bleeding by a pressure bleeding kit, it doesn't seem to make much difference. Are there any clever techniques, anything else I can be doing? Any help huuuugely appreciated! cheers Ken Quote Link to comment Share on other sites More sharing options...
JimAttrill Posted June 20, 2008 Share Posted June 20, 2008 I bleed Defender and Disco brakes by gravity alone. Fill the reservoir, open the brake nipple with or without a tube and wait until clear fluid comes out. Do up the nipple and wash off the spilt fluid with water. Works for me, but maybe only because of the coroliolis effect here in the southern hemispere Quote Link to comment Share on other sites More sharing options...
harle Posted June 20, 2008 Share Posted June 20, 2008 And so it goes on...So, as Les said, it was indeed a piece of cake to change the master brake cylinder, however, I'm having significant problems with bleeding the brakes now. I seem to have an airlock, and I've tried manually bleeding, and bleeding by a pressure bleeding kit, it doesn't seem to make much difference. Are there any clever techniques, anything else I can be doing? Any help huuuugely appreciated! cheers Ken Some people jack up the front of the vehicle, and wedge the brake pedal down, so that the master cylinder is in the open position, allowing air to raise to the top of the system. Personally i incoporate lots of tea breaks, whilst bleeding brakes of any older vehicles. Quote Link to comment Share on other sites More sharing options...
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