HHC Brake problems

[RKing]

I have had some recent problems with the breaks on my Seat Leon 2013

while driving on the motorway, the brakes suddenly locked up. Upon inspection it was the driver rear - a lot of heat coming from it.

After approx one hour while waiting, I was able to drive again but could occasionally feel the brakes applied while not pressing the peddle.

there were and are no warnings on the dash.

the mechanic thought it could be Hill assist pump (although strange when no warning codes) but he changed brake fluid and front pads as they were worn.

The HHC appears to come on every time the brake is applied, and releases after 2-3 seconds. He suggested driving a few short trips to see if the changing of the brake fluid and pads made a difference and drive knowing the HHC will come on!

I did but again, the brakes came on suddenly twice when not pressing the paddle and the front passenger brake was stuck and heating up on 2 occasions. It would release again after stopping for a while.

has anyone seen this before? Or know what might cause it?

No fault codes or dashboard lights
It has a manual handbrake if that’s worth mentioning

 

[RUM4MO]

Only observation after reading your posting is, both the listed wheel brakes are on the same (diagonal) hydraulic circuit.

 

[RKing]

Only observation after reading your posting is, both the listed wheel brakes are on the same (diagonal) hydraulic circuit.

So there are 2 diagonal hydraulic circuits?
If it was a pump issue, would you see it in both circuits?

 

[Ej444]

I can’t figure out how to post on here can someone help me!
I am having issues with the drivers brake it’s completely locked. It cannot be driven. We’ve replaced the caliper, disc, pad, drained it, refluided the car, pumped the brake. The wheel is not moving at all.

 

[GlekkeMatrak]

So there are 2 diagonal hydraulic circuits?
If it was a pump issue, would you see it in both circuits?

Yes, they are diagonal systems (MK100 ESC by Ate (Continental brand)). If you are not pressing the brake pedal, and the brakes come on by themselves, it means the ABS/ESC pump is providing the brake pressure by itself. It will not do that without any reason for it though. It's either some sensor signal causing the pump to provide pressure to certain circuits, or worst case it's some sort of short circuit but that would always have to throw an error on the dash.