Master Cylinder Rear Circuit

[Pete H]

Trying to bleed the brakes on my new car, the rear circuit just isnt pumping. I've even disconnected the rear brake line from the master cylinder and nothing is coming out, not even a drip. Drained the tank and checked the ports and their clear too. Does this mean the seal on the pistons failed, or a drillings blocked somehow ? The fronts circuit is happily sucking fluid down merrily. Its the uprated AP one by the way.

Pumped the pedal really slowly so I'm sure it cant have inverted the seal on the piston. Done this plenty of times before.

 

Cheers

 

Pete.

[6speedmanual]

sounds odd...

 

Are both chambers of the reservoir full of fluid?

 

If you look into the port for the rear circuit can you see the drilling into the cylinder?

 

Could the intermediate piston be seized?

 

 

Peter

 

 

 

 

 

6SpeedManual

*tongue*There's no such thing as too much BHP per Ton 😬

[Pete H]

Coming to the conclusion the master cylinder is defective, I think the piston seal on the rear circuit is too close to the feed hole into the rear chamber so it the cyliner is cutting off before it gets a chance to fill from the reservoir. Been able to coax some fluid into the cylinder by opening the union, pushing the piston in, closing the union, and releasing, basically creating a slight vacumn in the master cylinder, but still no pressure being produced.

 

Think I will ask Caterham for a new cylinder unless there are any other tricks for priming the cylinder.

 

Cheers

 

Pete.