Brake lines crossed ? Seems odd

morgan · Post by **morgan** » Wed Mar 23, 11 8:26 pm

Right - here is a good one for you all.
Just replaced all my brake lines (done a lovely job if I say so myself

) and last night was the big pressure test moment. WHen bleeding the system I noticed that the master cylinder reservoir (split in 2 - big at back, little at front) showed odd behaviour.

One front disk caused the rear reservoir to fall.
One front disk caused the front reservoir to fall.
Rears caused the rear reservoir to fall.

This seems very odd to me - its a dual brake circuit that brakes 3 wheels with one reservoir and one with another ?? Can this be right ?
I somehow expected it to be front = big reservoir. rear = little reservoir.

Diagram will explain better I hope. Its piped up like this (see diagram).
Should the two on the left be the other way round ? (This is how it was on the car, I have merely fabricated new and replaced)

Am I going mad ? Is this supposed to be like this ??

Thanks in advance...

charger01 · Post by **charger01** » Wed Mar 23, 11 10:56 pm

Morgan. Did you completely empty the reservoir? I know from when I replaced my unit(master cylinder) it needed bench bleeding before connecting the brake lines. The junction box is a proportioning valve which from memory should give you 75% front brakes & 25% to the rear end. It sounds to me like you have air in the system.

ANTON · Post by **ANTON** » Thu Mar 24, 11 7:28 am

The lines at coming out of the back are the wrong way round. The rear line out put goes opposite the in-put. and the front line out puts are opposite each other. Swap the two and you should be fine.

The junction box is a softy switch to stop total brake lose if either the front or rear fails.

morgan · Post by **morgan** » Fri Mar 25, 11 3:25 pm

Thanks boys. It explains a lot

The pain is that means taking off that cross bulkhead pipe again. Its a right nuisance... Guess wont make Ace on Saturday

Still - onward and upward. Much obliged.

ANTON · Post by **ANTON** » Fri Mar 25, 11 3:49 pm

The front one in theory will need to get shorter to go in the top one so you should have enough pipe to cut off the fitting and put the correct one on.

As the rear is so long you should be able steal a bit of length to swap the fitting.
Try this first before starting from scatch