Hi all.
I'm trying to bleed the brakes on my 12 plate Up! And having issues.
I'm using a pressure bleeder, and according to the VW workshop manual it should be done at 29psi.
At the moment, once the system is pressurised and I open any of the bleed valves, there is very little flow coming out!!! I guess first question is how many turns should it take to get flow? I'm expecting a 1/4-1/2 but that isn't doing it. Second, do I need to get rid of the vacuum from the brake servo by pumping he brake engines off a couple of times prior to connecting the bleeder? My thinking with that is that does the weight of the pedal create enough of a displacement to cause the servo to move the master cylinder Pistons enough to close of the reservoir inlet?
Assuming this is irrelevant which I imagine it is, why would I be suffering low flow at all valves? Could it be grunge in the bleed valves? It's only 4 years old and has had covers on them that whole time?!
What is currently happening is that as I open the valve;
The drain tube has a slight upwards bend before descending into a fluid filled bottle. Currently the brake fluid as it comes out of the valve fills the drain tube and forces the air up the tube until it gets to the highest point. It then doesn't go any further and air stays at the highest point and there is maybe a very very slow trickle of fluid over the top and down into the bottle. I would expect at the reservoir pressure applied that the fluid should force all the initial air in the drain tubing out.
Any thoughts, experience or tips much appreciated. Thanks.
Rob
I'm trying to bleed the brakes on my 12 plate Up! And having issues.
I'm using a pressure bleeder, and according to the VW workshop manual it should be done at 29psi.
At the moment, once the system is pressurised and I open any of the bleed valves, there is very little flow coming out!!! I guess first question is how many turns should it take to get flow? I'm expecting a 1/4-1/2 but that isn't doing it. Second, do I need to get rid of the vacuum from the brake servo by pumping he brake engines off a couple of times prior to connecting the bleeder? My thinking with that is that does the weight of the pedal create enough of a displacement to cause the servo to move the master cylinder Pistons enough to close of the reservoir inlet?
Assuming this is irrelevant which I imagine it is, why would I be suffering low flow at all valves? Could it be grunge in the bleed valves? It's only 4 years old and has had covers on them that whole time?!
What is currently happening is that as I open the valve;
The drain tube has a slight upwards bend before descending into a fluid filled bottle. Currently the brake fluid as it comes out of the valve fills the drain tube and forces the air up the tube until it gets to the highest point. It then doesn't go any further and air stays at the highest point and there is maybe a very very slow trickle of fluid over the top and down into the bottle. I would expect at the reservoir pressure applied that the fluid should force all the initial air in the drain tubing out.
Any thoughts, experience or tips much appreciated. Thanks.
Rob