10 replies to this topic

[MiniMrMan]

I have the big brake kit from zcars on my vtech and set about bleeding it the other day. I used a power bleeder setup to aid me (doing it on my own) both front and rear calipers bled up ok and i have a reasnable pedal feel. The only problem was that, after i let it off the jacks all the brakes where locked on. The only way i could move the thing was to release some pressure out of the front caliper whilst pushing on the brake pedal. If you push the pedal after this the brakes stay on. Not gud. Am Just being an idiot and missing something?

[gizmo]

Had that problem many times. was not enough free play at pedal. adjust rod to have just a bit of free play

[Poly_Patje]

Lol

I have sent him a PM at 15:38 with the same solution. Experienced the same thing last year when I upgraded the motorcycle brake calipers.

Edited by Poly_Patje, 09 May 2007 - 05:07 PM.

[markrally]

it sounds like you have the pushrods from the cylinder tot he pedal too long and is holding the cylinder pressure a little, it is a common problem, as a guide you should have 72 mm from the clevis pivot centre to the mounting face of the master cylinder, this should make sure the pedal returns fully without holding pressure.

Cheers

[MiniMrMan]

Thanks, that has sorted it, sort of... The rod has been welded to the fork by z cars, so it was a case of cutting it off and re-welding it or spacing the master up. I have spaced it up and now the brakes dont lock on Only thing is now no matter how much i bleed them i can not get a pedal, it goes to the floor unless pressed 3 or 4 times, then stops 1inch away from floor. Could i have spaced it to far? Would it have this effect?

Oh, and the hight of the pedal is not where i would want it, before or after i spaced it. - it is quite a bit lower than both the clutch and throttle pedal without pressing it?
Thanks.

[markrally]

What size cylinders have you got?
You should have 3/4" or 7/8" (22mm) For the brakes and 14mm for the clutch,
I have set my cylinders at 72 mm which just releases the pressure from the circuit and the pedal is all the way up. It is the same as what the std rod length is on a mini normally, as for it going to the floor? it sounds like you have a bleeding problem??
Re mount the cylinders on the bulkhead and chop the rods as you are probably not getting enough stroke in the cylinder either.
What calipers are you running? Wilwood 4 pots and z-cars handbrake rears?


Cheers

Edited by markrally73, 11 May 2007 - 08:53 AM.

[MiniMrMan]

I am running willwoods 4pots on the front and the single pot ford jobies that zcars suplied. I was sceptical about spacing it as the pedal was already to low and not on the stop before i spaced it off?
It is doing my head in, I have spent far to long on these barkes now! need it up and sorted for the lakes run-early june!
Thanks.

[Jammy]

Moved to Z Cars Technical.

[MiniMrMan]

Oh and I am running 7/8" master.

[adyzr1]

ayup mate , i had the same problem that i couldnt get pedal feel, it turned out the pedal was too low (should be level with clutch and accelarator) like the guys say as long as the master cylinders are fully retracted and have free play in the linkages they should bleed ok

cheers ady

p.s just been out in garage - pedal is level with clutch , and when depressed travels 50mm (my brakes have passed sva test)

oh and i used an easi -bleed kit (gunsons)

Edited by adyzr1, 11 May 2007 - 06:02 PM.

[MiniMrMan]

Thanks guys, got it sorted at last! The rear calipers need to be bled the wrong way up so the nips are at the top. I have a good pedal now.
Only thing is my pedal is a little lower than i would want.