Hi. All
I fitted an overhaul kit to my M16 callipers during the make do & mend stage of the build now I cant get them to bleed. I’m using a Mk 2 escort non servo MC, I Know it must be the fronts that is coursing the problem as I’ve blanked off the front outlet of the MC and I get a lovely pedal, Connect the fronts & its very spongy ( I Can press the pedal nearly all the way down) I’ve Bled them till I’m blue in the face, pressure & pumping. Hoses are braided with banjo’s, MC was sleeved & re con’d by Past Parts. Pedel ratio is 6:1 Any suggestions please. Can there be air in the top of the banjo bolt?

Assuming you have the callipers fitted on the correct sides with the nipples at the top.

Get an assistant to pump the pedal hard while you check for leaks use a torch and don't expect to see fluid only slight dampness, the loss of pedal is caused by drawing in air on the return stroke.


If not take one pad out at a time and pump the pedal once to check each piston is actually free to move, it is not unknown for pistons in Girling callipers to stop working if pushed hard back.

[Edited on 15/2/12 by britishtrident]

Thanks, Good Thinking

And also check that the m/c is returning fully when your foot is off the pedal.

Where abouts in Cambridge are you? I may be able to help .with a pressure bleeder As already suggested make sure the bleed nipples are at the top

Thanks for your suggestions but calliper pistons free to move, I also let each one out as far as a worn out pad would let it & pushed it back. Master cylinder returns fully. Callipers are the right way up. Could it be that it just needs a good blatt up the road to bed the pads in. I did notice the pads have only marked up on the outer 10mm when I had them out. I’m also trying the broom handle on the brake pedal trick tonight. Thanks for the offer of the easy bleed I live in Swavesey but I have pressure bled them with a home made gismo.

Pumping the pistons almost fully out and pushing them back so the fluid goes back to the master cylinder normally very effectively gets rid of any air out the callipers and pipe work by pushing the air bubble back to the reservoir.

While it could be the callipers not presenting the pads true to the disc surface I would still regard a leak as the most likely cause.

i had the same problem , 6 weeks later i still never solved it with many people having a go,
even changed the brake lines.
turns out the calipers were letting air in but not leeking fluid out.
brought a new set of wilwoods , fitted and working within 20 minutes.
one of the easy jobs on building the car turned into the hardest.

Thanks for the suggestion , I am beginning to think along those lines myself but having just spent hard earned dosh on the master cylinder after fitting a service kit and still not sorting the problem I’m a bit reluctant to jump that way. I think I’ll do a Basil Forty and give it a dammed good thrashing. Seriously there’s a short bit of private road near me and I’m going to try and bed the pads in first, My thinking being high pedal to calliper ratio on new possibly cheap fluffy pads with good but not new disks may be the course, anyway it’ll be a fun thing to try first.

another test ----

Assuming you have steel braided brake hoses that can't be clamped, working on each front brake pipe in turn disconnect at the caliper end and bock off. If the fitting is a female tube nut you can screw a bleed nipple in if a male fitting then you will need to make up a short adaptor pipe with a female fitting at each end.

You can prevent excessive fluid loss when doing this by simply filling the fluid resevoir up to the brim and stretching some cling film or thin polythene over the top and sealing it tightly with an elastic band or two.

Remove the cling film give it a couple of pumps to bleed it then try the pedal if OK then repeat test on the other side.