Brake Bleed Issue... Help Needed Asap

[Simon-S14]

Ok so i ive an s14 with s15 brakes all round (same shit as s14 anyway) braided lines, new pads, hydro handbrake and i cannot get a decent peddle feel. its spongy as hell and myself (a mechanic) and paul Sil-014 (also a mechanic) have tried every bleed method under the sun without any luck what so ever, the BMC was fine and working last time it was used, booster is fine, peddle is adjusted correctly also.

Basically with the engine running, the peddle goes 1/2 travel before engaging the pads.. not very confidence inspiring. we have tried cracking the lines on the hydro and bleeding them there also. no luck

HELP!!!!!!!

[Duncan]

I guess you have looked at the basics and there is no leaking anywhere....from there just simple stuff like pedal or mount flexing? BMC moving?

have you bled the abs? (having said that....I have never, ever needed to, but it is a possibility)

I saw you bled the handbrake (definately a potential problem).

No leaks at BMC or calipers? Do the caliper mounts flex?

I hate brakes that are not rock solid....but have always been able to get them through proper bleeding.

maybe take use through how you bled them??

[Simon-S14]

no abs on this car as its 100% pure track car. im with you on the solid brakes tho... these work but they defo are not confidence inspiring!

started off by doing a normal one man brake bleed with a hose on the nipple submerged in fluid. that didnt work so we did a pressure bleed with one guy pumping the brake peddle, then holding down and me cracking the nipple then closing.

also tried holding the peddle down while cracking the lines on the hydro slowly to let them leak out, then closing then releasing the peddle... that didnt change much.

nothing seems to be flexing much. the BMC was loose on the booster to start with but upon doing that up hasnt changed the feel at all.

no leaks as far as the eye can see

pretty stumped on this one

[DVS JEZ]

try an air bleeder. my hydro took ages to get right. mine was s13 upgraded to s15 brakes and the pedal was a bit lower with the s15 brakes

[Simon-S14]

never tried an air bleedy but i cant see how it would do any better then a pressure bleed?

want to explain to me the process you took with the hydro?

[DVS JEZ]

honestly, its hard to explain, i was the same as you, tried all the normal ways, then did some more research on these forums and ns.com, tried all those ways, cant remember exactly which one worked in the end.

[blind_elk]

You have the hydro connect the right way round?

You bled the master first?

Is there a difference in piston sizes between the S14 and S15 calipers?

Sometimes, there is a block inside the booster that the pushrod of the master cylinder rests against - is that the case here (it's missing)? It will feel like it's been bled properly, until you start the engine and get vacuum on the booster.