Ongoing Idle Issue, Barke Servo?

Still trying to get to the bottom of the issue on my Type 4 2.0 Litre wanting to stall when it should idle. I reckon as I press the brakes the revs drop, could this be that there is an air leak in the hose to the servo? I am thinking of replacing the servo hose and probably the NRV, what size is the hose (internal diameter)?

Cheers

 

Should say Brake not bark!

 

I cant remember the size of the hose off hand but easiest to get a new a new non return valve and then size the hose from that

 

12mm or 1/2", whateever you can get.

 

Engine idle will drop when you apply the brakes.
Tony

 

So this does not necessarily mean this is the issue then?

 

Just block it off and see! Dont understand why pressing the brake would do this. Is the servo working?

 

I believe the servo is working, I thought about a new check valve but have ordered some hose so when that comes I will have a look. Bizarrely the idle failing is intermittent so looking for clues, I wonder if its a small air leak or crap in the carbs, have done the new fuel filter, recently had the tank out and inspected it and it was clean. Clutching at straws really, also tried Redex in the petrol...

 

I had a leak on my servo pipes. Intermittent but with it on the ramp and running I could make it run badly by moving the pipes around. Check valve is simply suck one way air come through. Suck the other and it doesnt. Works or it doesnt but shouldnt cause your problem.

 

I had one t'other day with leaks in the manifold elbows that increased revs at tickover when the pedal was pressed. Otherwise it hunted when just sitting there idling.

 

Had a porous servo pipe on a T25 which was causing all kinds of running problems and found the leaking area using carb cleaner spray (from memory I think WD40 works too and is a less volatile option)

With the engine running, spray onto suspect areas and the revs will increase if air is being drawn in but watch out for loose clothing and the usual hazards associated with wizzy, spinny things in a confined space

Hope you get it sorted

Mr B

 

Thanks for the replies, does sound like a small leak, will try the spray trick, see if it locates the problem, all connections within the engine bay are new including the elbows so if this is the issue, must be the servo line, Zeds post really makes me think its air leaking in....will post when I have had a play...

 

Just an update, tightened the nuts on the carb to manifold fittings, appears to be now ticking over quite nicely, they needed about a turn on each nut to fully tighten, hopefully now solved but there is still a little hesitation at speed, will see how it goes....