Problem with brake caliper or brake pump

[REBAcars]

Hey,

I have a big problem with my trackday car.
It has totally no braking power.
I have placed new brake lines.
Have put racing brake fluid in it and installed new brake pads.
But nothing of that seems to work.
There is also no air in the brake lines.
Wich makes me think there must be a problem with the brake pumps or the brake calipers.

How can i find out where the problem is?

car in question

[Dave Brand]

When you say "no braking power" do you mean you have no brakes at all, or just that very high pedal pressures are needed to get the required braking effort?

If it's the latter it's possibly because you're used to a road car with servo brakes & in reality there's nothing wrong with your race (I hope you intend to race it!) car.

[The Wookie]

If they're new racing pads that you've fitted they will need bedding. Without this the brakes will feel 'wooden' i.e. a fair bit of travel, no bite and increasing pedal effort with more brake demand.

My rule of thumb for bedding racing pads is 30% braking effort for first lap of a reasonable sized circuit, 60% for 2nd lap, 90% for 3rd lap, then a lap with minimal braking to cool off. If you're inexperienced on track or doing sprints/hillclimbs then you might want to get some more road biased pads as you wont be generating enough heat to get them working.

You don't mention what you mean by no 'braking power' though. If the pedal is rock hard then you've probably got the master cylinder sizing wrong for the caliper piston sizes you have. If the pedal is very long or drops to the floor then you either have air in the system (always worth re-bleeding a couple of times to rule it out as would be amazed how much effort it can take to bleed a system, particularly if the master cylinder has been dry as they are a pain to bleed and preferably should be done by themselves) or a master cylinder issue.