[GB SISSON]

I have done a lot of tests on things like radiators with an assortment of bicycle inner tubes and hose clamps. Radiators test real nicely with bicycle tubes! It's a little harder in this case. Are valves out? Let's say they are. Assemble a valve assembly with the valve stem smeared with silicone sealant. Now goop up the guide as well and install with more sealant under the valve head. Install the keeper. Now at the manifold end it's great to have a wood shop with various belt sanders. I would take an appropriate sized piece of pvc, abs or whatever pipe junk is around and taper the tip and slather it up and tap it in with a hammer. This is wordy, but 10 minutes should have you to this to this point. Ok, let sit over night. Cut a length of inner tube with the valve stem perhaps mid way. Hose clamp one end onto the pvc pipe and the other end to a pipe cap or wood dowel, trailer ball, shift knob, neck of a whiskey bottle. You get it. Pump up the tube and see if it holds. If like me you have some broken manifolds you could also saw off a few inches and put a cardboard gasket with sealant under it and hose clamp the bike tube to that.