I’ve an issue with the exhaust brake on my 58’ plate Scania p series…it’s not working.
Now, I’ve run the fuse and switch through a multimeter; fine.
I’ve tilted the cab and checked the free movement of the Pistons - fine.
I’ve lightly pressed the foot brake with the cab tilted and can hear air being demanded from the air tanks… But nothing bloody happens. It all seems to point to the square metal thingy which the air supply lines run from to the Pistons.
Now of course I’ve checked for leaks. There is a slight (I mean tiny) leak from the line supplying the piston on the exhaust; and a tiny leak coming from a small hole on the manifold, directly beneath the piston on the manifold.
So what’s wrong!?
My next question; what is the upper piston on the manifold for…?
The piston on the manifold controls the flap valve that allows exhaust gas into the heat exchanger then into the induction manifold.
When you press the footbrake the exhaust flap valve closes to produce back pressure and it also opens the EGR flap valve.On over run it just opens the EGR valve to cool the cylinders
The control unit opens one or both flap valves depending on the signal from the ECU.
Sounds like operating solenoid on the brake element has gone open circuit on yours
Bking:
The piston on the manifold controls the flap valve that allows exhaust gas into the heat exchanger then into the induction manifold.
When you press the footbrake the exhaust flap valve closes to produce back pressure and it also opens the EGR flap valve.On over run it just opens the EGR valve to cool the cylinders
The control unit opens one or both flap valves depending on the signal from the ECU.
Sounds like operating solenoid on the brake element has gone open circuit on yours
Cheers mate - any idea where I can find the solenoid? And would this not come up as a fault on the computer? I’ve run the historical codes and there’s nothing showing for the ECU or the exhaust brake system…
No strange on scania it does not come up as a logged fault but saying that had one the other day with no power.Removed the diesel exhaust filter and the whole matrix had melted but no fault codes.
Just a bloody strange vehicle.Dont think you can buy the solenoid you got to buy the complete unit.Could be wrong as I only repair the vehicles.Good luck.
