Unable to bleed: Please help!

Technical Area Wheels, Tyres & Brakes
2

Hey all, my car is an MX5 MK1 1.6 eunos - No ABS or anything like that.

So, my brakes have decreased greatly in efficiency and the break pedal hardly moves.
The brake peddles gone very solid.  When pressing the peddle there is a complete lack of feel for the brakes working.

Although the pedal feels a bit ‘boingy’, i wouldn’t say spongy.

i’d then assumed that it might be air in the lines so whipped the drivers side front wheel off and undid the bleed nipple.  When pressing on the brake pedal, nothing changed and no fluid came out.  

The pedal would not push any further than it would with the nipple done up.

My thoughts then turned to the master cylinder, thinking that perhaps it is seized.  So, I removed one of the hard lines that loop off the master cylinder to a junction box.  Now when pressing the brake pedal, the pedal depressed all the way to the floor with ease and fluid came out of the line.

So this leads me to believe that there’s nothing wrong with the master cylinder.

Does any one have any ideas?

Is there anything that would prevent the front from bleeding altogether and stop the pedal from moving altogether?

Now that I removed the hard line, there is air in the top of the system which I am not too bothered about as i’ll be bleeding the full system, once I get to the root cause of the issue.

3

i’d check for a blocked bleed nipple first, I’ve known it in the past. Try remowing it completely and pressing the brake.

4

Are either of the front brakes dragging? Does the disc rotate freely?

Assuming the caliper piston and sliders aren’t seized, I’d start to work backwards from each caliper.

Crack the banjo joint where the flexy pipe meets the caliper and see if the pedal pumps fluid easily that way.

If yes, then it sounds as thought the caliper needs to be stripped, cleaned and re-sealed or replaced.

If no, then it could be that one or more flexy pipe has broken up inside (although that’s fairly unlikely).

Robbie could be right about the bleed nipple, but there may be an extra problem with the pads seized on their mounts within the caliper.

If there is a fair bit of rust on the discs / pads and caliper, then in reality you are looking at a proper rebuild of the brakes.

Will be well worth it.