Adrian Posted May 10, 2019 Report Share Posted May 10, 2019 Morning all. Attempted to bleed the brakes yesterday on the mini, did it in the order the Haynes said. First 3 fine but the final front offside has no flow. I think I’ve traced it down to the banjo union, if I slacken off the banjo bolt I get seepage of fluid. new pipes, reused old joint. Any ideas? thanks Adrian Link to comment Share on other sites More sharing options...
Adrian Posted May 10, 2019 Author Report Share Posted May 10, 2019 Hi Tony, all 3 corners are good. I have fluid to the banjo but nothing feeding the to the offside. Near side feed through it is fine Link to comment Share on other sites More sharing options...
poppyman Posted May 10, 2019 Report Share Posted May 10, 2019 Hi Adrian, Have you tried clamping the flexi hose? I doubt it will be the banjo union. Tony. Link to comment Share on other sites More sharing options...
poppyman Posted May 10, 2019 Report Share Posted May 10, 2019 Sorry Adrian, Is it a tandem system? Tony. Link to comment Share on other sites More sharing options...
Adrian Posted May 10, 2019 Author Report Share Posted May 10, 2019 Yes it’s split front to back. Following your doubt about the banjo, I took the front calliper off and disconected. I got flow so the problem is actually the calliper, brand new. Should I be using a copper washer at the flexi hose connection? Does the connection depress something inside to allow flow? just thought to loosen off the hose from the calliper and I got flow. This implies I need a thicker copper washer? Link to comment Share on other sites More sharing options...
poppyman Posted May 10, 2019 Report Share Posted May 10, 2019 You could try it? or if not to much trouble, try swopping hoses from side to side, that would rule out a hose problem and point to the caliper. Very odd though? Tony. Link to comment Share on other sites More sharing options...
Adrian Posted May 10, 2019 Author Report Share Posted May 10, 2019 can you stack washers to achieve the clearance? I would assume I should stay well away from grinding down the end of the hose as they are supposed to be precision built. Link to comment Share on other sites More sharing options...
poppyman Posted May 10, 2019 Report Share Posted May 10, 2019 You can, but i would'nt use more than two as a permanent fix. There has got be a fault with the hose or the caliper. That is why i suggested to swop the hoses to find what is causing the problem. Tony. Link to comment Share on other sites More sharing options...
Adrian Posted May 10, 2019 Author Report Share Posted May 10, 2019 I've put two washers on the offending connection and it now bleeds fine. I've ordered some more copper washers of a better size and will attempt to bleed the system fully next week when they arrive - I wonder what other issues I'll be faced with once complete - probably no pressure at the pedal for a start! Watch this space! Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 10, 2019 Report Share Posted May 10, 2019 cant visualise but if screwing the hose into the caliper causes an obstruction there has to be a fundamental cock up in the caliper is the fluid drilling off set to the threaded portion ??? two washers is not advised on brake systems , theres a lot of pressure in these an eagle eye mot might even give it a rejection Pete Link to comment Share on other sites More sharing options...
poppyman Posted May 10, 2019 Report Share Posted May 10, 2019 Adrian i have to agree with Pete, there must be something wrong somewhere. I think you might even end up with a brake inbalance between the two sides. You really do need the front brakes to work, as they do all the stopping on a mini. Like i say, swop the hoses around.... It will then tell which is at fault.... Caliper or Hose. Tony. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 10, 2019 Report Share Posted May 10, 2019 echo that Pete Link to comment Share on other sites More sharing options...
Adrian Posted May 10, 2019 Author Report Share Posted May 10, 2019 Well if it is a potential safety issue I’ll swap the calipers ( ironically easier than the cables in the first instant) but I know it’s just to test and not the right way round. I suppose i’ll Have to get a replacement if it’s defective Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 10, 2019 Report Share Posted May 10, 2019 so whats down the tapped hole in the caliper thats getting blocked when you screw the hose in ??? Pete Link to comment Share on other sites More sharing options...
poppyman Posted May 10, 2019 Report Share Posted May 10, 2019 I know what you mean Adrian, those hoses are an absolute pig to do. At least they wont be rusty. It will be interesting to find what the fault is though? I have never come across it before, and i dont think Pete has either? Tony. Link to comment Share on other sites More sharing options...
Adrian Posted May 11, 2019 Author Report Share Posted May 11, 2019 I actually think the depth of the thread in the caliper is a fraction too short (or the hose thread is too long) and when tightened up actually seals itself against the bottom face of the caliper thread. i’ll have a look this morning. I’ve ordered some 1.5mm washers as the current ones are no more than 1mm. They may just be enough to get the clearance without using 2. Adrian Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 11, 2019 Report Share Posted May 11, 2019 Adrian ok but surely the hole in the cal and the hole in the hose end must align even if the threads bottom out may be not ??????????? Pete Link to comment Share on other sites More sharing options...
Mad4classics Posted May 11, 2019 Report Share Posted May 11, 2019 OK, found an old Mini caliper - it measures 0.75" deep to the bottom of the hose connection. You're using braided hoses looking at the picture you posted; has it got the correct length end fitting? I've pictured a goodridge hose which measures just shy of 1/2" long - so with the copper washer there should be plenty of clearance to the bottom of the caliper connection. David. Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 11, 2019 Report Share Posted May 11, 2019 Surely, as Pete says, even if the hose is too long and there are exposed threads the holes in both hose and caliper should be lined up and there should be fluid passing from the hose to the caliper? Link to comment Share on other sites More sharing options...
Adrian Posted May 11, 2019 Author Report Share Posted May 11, 2019 I do really enjoy this forum - knowing that problems and double checks can be resolved without pre judging my ignorance! But unless I'm mistaken my ignorance may be the cause of the problem. So this morning I've looked at the clearance in the callipers, one measured 12.74mm and the problem one measured 12.33mm. Now the thread length is the same as Davids. I tapped the centre of the calliper with a smaller diameter bolt and the resultant measurement was 12.93mm so it moved. So from what I deduce is the hose feeds directly behind the piston and the problem piston was far enough back to make contact with the end of the hose. As I was using an eezibleed I guess the pressure was insufficient to move the piston forward. So the question of holes lining up doesn't seem to apply because there is no hole inside the calliper, just the back of the piston. Forgive the drawing - art was never my strong point. Make sense? Adrian Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 11, 2019 Report Share Posted May 11, 2019 well thats a oddball sorted well done .....even if we made you look twice Ha ! Pete Link to comment Share on other sites More sharing options...
Colin Lindsay Posted May 11, 2019 Report Share Posted May 11, 2019 That's an unusual one to someone like me, used to the Triumph / BL system or others where the hose connects into the top of the caliper, but well spotted and I hope it's sorted. Link to comment Share on other sites More sharing options...
NonMember Posted May 11, 2019 Report Share Posted May 11, 2019 If the hole that the hose screws into is just a parallel hole into the chamber, as you've drawn, then I can't see any problem with filing a mm off the tapered end of the hose. It's not doing anything as there's nothing for it to bottom onto except the piston, which you don't really want it to touch. Link to comment Share on other sites More sharing options...
poppyman Posted May 11, 2019 Report Share Posted May 11, 2019 Go back to the old fashioned way Adrian, good hard press of the pedal Glad you are sorted. Tony. Link to comment Share on other sites More sharing options...
Pete Lewis Posted May 11, 2019 Report Share Posted May 11, 2019 yes down quick back slow.........reminds me of something else pete 1 Link to comment Share on other sites More sharing options...
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