Has anyone had experience with the rear brake set-up as sold by Classic? It's all fitted and they've been bled at least 4 times but I can't get any pressure at the pedal and no movement at the brakes. There's no leakes and fluid is coming from the calipers but it's like the pistons are seized but they can't be as the handbrakes work. They are brand new but came with no information at all but someone must have a clue. Please help as I have a distraught son who thinks the world is at an end!! Also I may add the master cylinder is new and worked fine when there were drums at the back.

You can try a vacuum bleeder, i bought one and it works great, you can bleed the brakes with one person.

But how would a vacuum bleeder affect the rear brakes any different when normal bleeding still has fluid coming from the rear calipers? Again the master cylinder, how would that make any difference? It's like I need more pressure (?) to the rear.

I believe the disc's need a residual pressure valve fitted, but it sounds like a bleeding problem too.

x 2 on the vac bleeding

Matt, what is a residual pressure valve?

This is from the CB site

http://www.cbperformance.com/pressurevalve.html 

make sure your bleeder screws are at the highest point.
If not, swap the calipers to the other side, so they are.

Also, some times once the master cylinder pistons travel in the area where they have not been in years,(like when bleeding),
they can damage the seals and not work like they were before.

Vacuum bleeder will remove all the air from the system were normal bleeding with the pedal might not, good point about the nipple position, residual valves came on some brum brake master cylinder.

Yeah, even with a vacuum bleeder, some trikes I work on, I have to remove the caliper and hold it high with a gradual gradient upwards towards the bleeder so all the air will be evacuated.

Also how much fluid are you getting comming out of the bleeders , ie is it a good squirt or a dribble as if it's just a dribble or not at least a decent squirt then chances are your flexible brake lines are stuffed and are blocking the fluid getting to the calipers at full pressure and hence giving you a soft peddle

Thanks guys that gives me something to work with, Andrew all the flexible pipes are new as are the hard pipes plus all the calipers are new and the master cylinder. The fluid is squirting but the pedal is as soft as anything, the front brakes work, just the rears are not so the residual pressure valve may be my next port of call. I'm going to shoot out this morning and get some more fluid and I guess when my son gets home from whichever party he went to last night I'll be bleeding brakes !

forget the residual valves , thats not your problem.
maybe the new master is bypassing on 1 circit
more than likely needs bleeding, you may have to take the caliper off and hold the nipple up as high as possible the bleed.

Hi

I put a new m/c in L bug a few months ago, front circuit bled straight away, the rear circuit refused pass any fluid at all. I used my vacuum bleeder and it got a pedal straight away then.

I reckon the seals had lost tension against the bore.

Do you have the correct free play?

Steve

I have a vacuum bleeder if you get stuck.

Thanks for the offer Shane but I've put something together pretty much the same as an Eezibleed where it's pressurised (surefire way to find any leaks!) but that didn't work, plenty of fluid from the back brakes so now I'm thinking along the lines of the master cylinder needs looking at even though it worked fine before the brake change my son may have got too eager and maybe pressed too hard when there was no fluid in the system and the pistons are stuck or at least the one that controls the rear, does that make sense to anyone other than me?

Well we removed the m/c and there's hardly any pressure from the rear pipe outlet so I thought I'd sussed it BUT I had another dual circuit m/c and first thought about swapping the seals over but before I did I checked and found that that m/c did the same thing. It was all highly technical - holding my mouth to an outlet whilst pushing in the plunger! Are they supposed to put less pressure to the rear? I wouldn't think so but this is a bit of a coincidence, I do have an old single circuit m/c that I'm seriously thinking of digging out, cleaning up and using as this has started to drag on too long!

Well I've been playing with these bloody brakes for so long now that all moisture has been sucked from my body! I can't get any pressure other than a slight bit at the end of the pedal travel. Fluid is squirting from all calipers - probably more from the front than at the back, I was going to put the old m/c back in as when I checked it was all in decent condition but when I was putting it in I discovered the inlets from the reservoir were a different size and I didn't have the old ones. So new m/c back in, pressurised the system, bled it all twice this morning and still nothing except that slight pressure at the end of the pedal travel. To me it still feels like it's a m/c problem where the piston for the rear is not sealing but on checking the seals all look good and it's a new cylinder, the other piston appears to work 'cos the pressure at the end of travel and if I get the front wheels off the ground and get my son to press the brake I can't spin them. I'm all prepared to set the bloody thing alight as I've spent my entire holiday so far sodding about with my sons car and done nothing to my own!

Have you tried bleeding the master cylinder? Pressurize the system then crack the metal pipes at the master cylinder and see if you get any air out from there.

I'm willing to give anything a try Graham although I can't seem to understand why that would give any different result as I'm getting fluid through the whole system. I'm pretty much convinced I must have a duff m/c either that or I've left the pads off the rear brakes (joking but that's what it feels like!)

I made the mistake in my younger days of purchasing a sherman rear disc brake kit, i had the same issues as the displacement of the rear caliper was greater that the wheek cylinder that it replaced, same syptoms as yours, would not bleed and give a good peddle, when i got it sort of happening i noticed it was blueing the front rotors and the rears were not working as the rotors still had the machine marks on them, i put it down to the master cylinder disign, when it works as the maker intended the piston for the rear brakes pushes the piston for the front brakes using the brake fluid under pressure and not any mechanical means inside the master cylinder, when you change the balance by introducing more displacement at the rear for what ever reason this no longer happens and the rear piston bottoms out on the front piston giving you a low peddle and poor braking and no ammount of bleeding will fix this, has anybody else have these brakes and what experence have you had with them , I notice that there has been no responses from people that have these fitted to there cars already, are they an approved conversion and have they been engineered to be legal when fitted to a vehicle, when i disigned and fabricated my four wheel disc brakes carefull calculations were made to determine what calipers could be used back and front to work with the standard master cylinder with any proporting valve fitted and still have a good peddle and the correct brake bias. In the end i took them of and replaced them with a set of type three drums.

I have Sherman rear disc brake kits on both my bug and my trailer (it is built on a type 3 rear end), and both work very well. I have had the ones on the car for 7 years (130,000km) now, and no problems at all.

Shane what you said is pretty much what I've just been told by a mate who popped 'round and I'm sure other people who have bought these brake kits must have had the same problem which makes me wonder why no one else has responded (surely we can't be the only ones who've bought them?).Is there a way to fix the situation other than junking the $600 rear brakes? i.e. another m/c .

try asking over at thesamba.com

Can I ask are these EMPI kits??

Well I've just emailed George at Classic as he is earning money from these brake kits see what he has to say and eagerly await a response. I know he's not back till Tuesday but it feels like we only bought 'part' of a kit.

The rear brakes that i had used fiat calipers and had all of the same issues the you are having with yours, as far as i can see if this is the case you would need a different size bore on the rear to circuit to bring the displacement into line, just a thought, have you checked that the calipers are adjusted up, have you tried bleeding them with the hand brake on and how are the calipers adjusted, is it by the hand brake or reversing the car, maybe it does need a residual valves in the rear circuit. PS, a single circuit master cylinder would work and give you a hard peddle but what brake bias you got would be anybodies guess, also the legallty issues raises its head because you are required to have a dual circuit master cylinder with disc brakes.

Is it Camo70 or just Camo with the bright orange beetle unfinished fat chrome wheels? Show quality.

He has these brakes and remember him having an issue with his. I think the pad was not square with the disc. Give him a pm at least he has these brakes and he might have a bit of help...

I have mine all wrapped p ready to put on soon so i am watching with interest.

Cheers

Have these brake's been approved to use on the street.

here is camo thread

http://forums.aussieveedubbers.com/viewtopic.php?tid=67570&page=7#pid837565