mk2 rear brakes work to well

[leeroy20vt]

no m8 master cylinder off a mk3 16v only has 2 outputs so 1 is front and one is rear hope that makes sense im crap at explaining things soz

just taking it up road again and with reducers fitted the rear did not lock up and its peeing hard here so seems ok

[rubjonny]

mk2s only use 2 outlets on the mc as well, what they have are 2 T pieces to split into 4 lines for each corner.  i agree with ben, at least split the front brake circuit across the 2 mc holes for safty sake, i.e. run pipe from frotn outlet to 1 sidfe, and pipe from rear outlet t'other

[leeroy20vt]

would that know the balance off fronts out tho ?

as u would have 2 rears 1 front on one and 1 front on other or am i not getting it  :embarassed:

[Ben Lessani]

No, your rear bias should have 2 in and 2 out, it keeps the 2 circuits separate and regulates flow through each independently. So whatever you adjust it to, will apply to both left and right circuits.

[leeroy20vt]

that would mean buying another bias valve  hmmmmmmm

even rally design said it would be ok the way it is 

[Ben Lessani]

that would mean buying another bias valve  hmmmmmmm

even rally design said it would be ok the way it is 

There is nothing functionally wrong with your set up (ie. it shouldn't cause the imbalance you are seeing), assuming its not in back to front.

Diagonal split systems are pretty much a standard with any braking system, it is the recommended set up for safety, and if I were throwing myself round a circuit - the last thing I want is the car to pop a nipple and loose both front callipers and cause the car to endo!

[leeroy20vt]

cheers ben i understand were ur coming from i do and yer safety is number 1 not just for me but others

the complete set up is all new so fingers crossed will be ok for saturday will not be pushing the car as only just put it together

i put those reducers in and rears are not looking up now till u wind the bias valve to more brake and even then there only just trying to

i will have to try and get another valve and replumb

[Paul86S2]

To fit a brake bias valve you need to have your brake system split front to rear as you have done. You cannot split it diagonally and fit two bias valves - you will never get the two sides set up the same.
As far as safety is concerned you have two circuits so if one fails you have the other to fall back on. It isn't an ideal situation with having one circuit fail and whether the circuit remaining is diagonally front and rear or just the front or rear it is going to give you a worrying time. Having one diagonally opposite circuit working is truelly awful with one strong front brake and one weak rear brake working you will be lucky to keep the car in a straight line, at least with a front rear split you will have equally performing brakes working at one end of the car.
Stick with what you have.
If you had a three port master cylinder you could run the rear brakes off of one port and each front brake off of its own port.

Going back to your problem I know some master cylinders have a higher proportion going to the rear port (closest to the operating rod) but I think this is for cars with a front rear split so I doubt VW ones would be set up this way.

Paul

[leeroy20vt]

paul ur a diamond dude just what i wanted hear thanks bud

[Diamond Hell]

Your set up is fine, the issue is that you're struggling to get the pressure to the rears down enough.  The measures suggested in the track section are fine.

The problem in here is a lack of understanding (Paul excepted) regarding what you've done and why.

The ports on the MC are all the same volume displacement.  Talk to a specialist supplier to see which bias valve reduces the pressure the most.