I can hear my vacumn pump running for quite a while after start up.

I checked under the bonnet (right hand side facing foward where all the vacumn tubes meet at a junction box (part name)?
I can hear air noise (sucking?). 2 of the plastic inlets on the junction box look split - bottom left and bottom right tube junction.

Is it acceplable to silicone seal the splits to make a repair?
Please advise the part name.
Thanks