Caldiniho Posted April 2, 2018 Share Posted April 2, 2018 Hi all, I have a rather complicated brake problem, All brake pipes were upgraded due to corrosion and M.O.T failure, since then I have not been able to get them to bleed properly. I could bleed the fronts (calipers and vented discs) but the drums at the back were an issue. I got rid of these and have now fitted a pair of solid discs and a pair of defender front 4pot calipers. When bled using an EZ bleed I get absolutely no pedal, the brakes only work when the pedal is nearly all the way down. If I clamp of the rear flexi the pedal comes all the way to the top, if I put a bleed nipple in the t piece on the back axle to isolate just one of the rear calipers the pedal comes all the way to the top too (it doesn’t matter which caliper I have tried isolating both it’s still same). Any ideas what this could be? Quote Link to comment Share on other sites More sharing options...
miketomcat Posted April 2, 2018 Share Posted April 2, 2018 You have put 4 pot calipers on the back therefore it requires more fluid to move them giving long pedal travel. If you fit the correct calipers your problems should go away. To be honest in my opinion front calipers on the back is dangerous. If you brake hard the excess brake force on the rear will cause the truck to become unstable and likely crash. Mike Quote Link to comment Share on other sites More sharing options...
Caldiniho Posted April 2, 2018 Author Share Posted April 2, 2018 Hi Mike, Just to mention I had this problem with correctly adjusted drums, the front calipers on the back should still only recieve the same amount of braking pressure as before, whereas all that is happening is the same as when I had the drums. As a side note I have just tried a pair of disco rear calipers and I still have the same 🤔 Quote Link to comment Share on other sites More sharing options...
mmgemini Posted April 2, 2018 Share Posted April 2, 2018 I have to agree with Mike. Fit the proper rear callipers Quote Link to comment Share on other sites More sharing options...
western Posted April 2, 2018 Share Posted April 2, 2018 I agree with Mike & Mike above. reckon you'll find the rear end trying to do far to much of the braking & it might even swap ends on you, LR fitted 2 piston calipers on the rear to prevent over braking, my 110 had rear drums, never had a problem bleeding them, make sure the cylinders are pushed right in, the shoes are correctly adjusted & it should be fine. recently swapped my rear drums to correct 2 piston 110 rear calipers, no problem bleeding & brakes are very powerful & good pedal feel. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted April 2, 2018 Share Posted April 2, 2018 Brake bias valve? Mike Quote Link to comment Share on other sites More sharing options...
Eightpot Posted April 2, 2018 Share Posted April 2, 2018 (edited) Is the master cylinder stroke volume enough to operate 16 caliper pistons? Edited April 2, 2018 by Eightpot Quote Link to comment Share on other sites More sharing options...
landroversforever Posted April 3, 2018 Share Posted April 3, 2018 14 hours ago, Eightpot said: Is the master cylinder stroke volume enough to operate 16 caliper pistons? This. I can't remember the size of the 2 pistons in a 2 pot caliper but your problem is likely to be the fact that you've not got enough fluid movement to the rear so its making it all feel spongy thanks to too much pedal travel. As above, the 4 pot calipers on the back isn't a good idea as they were always 2 pot calipers. Quote Link to comment Share on other sites More sharing options...
Bowie69 Posted April 3, 2018 Share Posted April 3, 2018 19 hours ago, Caldiniho said: As a side note I have just tried a pair of disco rear calipers and I still have the same I suspect that when you did this, there was air in the system. As others have said, 4 pots on the rear will not be given enough fluid, hence when you block one off, the pedal goes nice and firm. 4-pot calipers are a complete no-no on the back, dangerous to you and others if used on the road. Quote Link to comment Share on other sites More sharing options...
western Posted April 3, 2018 Share Posted April 3, 2018 on my '89 110 the front & rear calipers use 46mm diameter pistons, IIRC earlier vehicles had 41mm diameter pistons. Quote Link to comment Share on other sites More sharing options...
Caldiniho Posted April 15, 2018 Author Share Posted April 15, 2018 On 03/04/2018 at 12:51 PM, Bowie69 said: I suspect that when you did this, there was air in the system. As others have said, 4 pots on the rear will not be given enough fluid, hence when you block one off, the pedal goes nice and firm. 4-pot calipers are a complete no-no on the back, dangerous to you and others if used on the road. So why would have the exact same problem with drums? And even when adjusting just one? Quote Link to comment Share on other sites More sharing options...
western Posted April 15, 2018 Share Posted April 15, 2018 could be a few reasons, brakes not in the correct place, pins for the adjustment misaligned or not on the adjuster, bleed screw in the wrong hole. Quote Link to comment Share on other sites More sharing options...
miketomcat Posted April 15, 2018 Share Posted April 15, 2018 As I said earlier replace your bias valve. Mike Quote Link to comment Share on other sites More sharing options...
Eightpot Posted April 17, 2018 Share Posted April 17, 2018 On Sunday, April 15, 2018 at 4:22 PM, Caldiniho said: So why would have the exact same problem with drums? And even when adjusting just one? Drums can have similar problems but not related. The main problem is wear on the adjusting cams and the pegs on the shoes, or even badly made parts. If the shoes aren't capable of being adjusted out until they lock the drum solid, it means worn adjusters or badly worn shoes, or worn drums or all three, and there will be too much travel. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.