Whats this pipe?

Going to expose my lack of knowledge now. When topping up the oil today I noticed a pipe hanging loose above the filler cap, I can't find a reference to it in the manual and can't see anywhere obvious that it comes from. It's about 200mm long and the other end is connected to the top of the air cleaner, can anyone point me in the right direction please?

 

if it goes into the air cleaner it's possibly an engine breather of some kind i would guess.

 

It appears to be a fuel tank breather, it should be attached to a T piece on the roof of the engine bay, then it goes to solid breather pipes up both of the chimneys on either side of the engine bay .

edit..... it appears I was looking at the wrong pipe.So feel free to ignore the above.

 

Since it appears to be the other side of the air induction pipe I'm wondering if its the vacuum pipe that runs to the inlet manifold from the thermal valve inside the air filter If there is another stub pipe beside it on the air filter then there should be a pipe from it to the valve on the inlet pipe

 

It's the vacuum line from the carb that drives the warm air flap. Or (more likely) the vacuum line from the thermo valve in the air cleaner to the actuator on the filter snout.

Have a search on here & elsewhere...been covered many times

 

Thanks all, gives me plenty to go at

 

The last couple of replies.

 

There is another inlet right next to where the hose comes out of the air filter, it's so short that it can't really reach anything else. Could it just loop in and out?

Hoping that when this is sorted it might explain some of the other problems we have had, we used to get a heavy dose of fuel fumes in the cab when we filled up but that has mysteriously stopped and I have replaced the heater cables but still have no heat. Could be linked to either?

 

If you take a photo of the attached end , I will check mine and post a picture of where the other end is attached in mine.
It's a 1.6 std pict carb and oil air filter so if yours is the same it shou
D help
Al

 

On the air intake "snout" of the air filter there is a vacuum operated switch. There should be a pipe from here, to one of the spigots on the air filter body. From the other there should be a pipe to the carb or manifold.

 

Thanks for the diagram Snotty, all the hoses seem to be there but connected up in a different order so I have added some more pics to clarify what I am on about. The T-piece connections all seem to be ok.

 

Sorry different air filter to mine
Al

 

The mystery solved, I think.

The t-piece looks ok - it just feeds tank fumes into the air filter.

You need to move that transparent pipe connected to the rear port on the carb to the unused brass connection on the thermo valve (I can't actually recall which valve connection is which), instead of the "snout" where ir appears to go at the moment. Then connect the dangly vacuum tube to the snout connection which is now free.

Rear carb port provides a vacuum, which goes to valve. When it's cold, valve's open (I think), routes vacuum to snout actuator that opens the flap to pick warm air up from around the exhaust. Engine heats up, valve closes, cooler air now picked up through snout in engine compartment.

Whether yours works is anyone's guess The little actuator rod in the snout can rust through, so it does nothing. Worth getting all this stuff working...

PS You could do with some new pipes actually...

 

Perfect, I will rig it up as you suggested and make sure it all works then get some replacements to fit. Cheers