Cutting out when braking

[Morris_Jay]

Hello all,

I am new here, I have 2 little moggies. One traveller I am restoring and one 4 door saloon. I am having a bit of trouble with my saloon, I started it up today (it gets used almost everyday and has been the most reliable car I have ever had) and it made an airy/sucking sound. This calmed down almost straight away but when I tried to drive off as soon as I touch the brake pedal it cuts out.

Any ideas?

[aupickup]

have you filled the damper pot on the carb with oil, this should be done

[bmcecosse]

Do you have a brake servo fitted ?

[Morris_Jay]

Hi and thanks for the replies. The damper pot has oil in it and there is no brake servo.

[bmcecosse]

Hmm - so - does this happen when you have your foot on the clutch pedal as you stop - if you slip it into neutral (and keep away from the clutch) and then stop - is it ok ?

[MarkyB]

The source of the "airy/sucking" sound needs to be tracked down.
If there is no obvious culprit take the air cleaner off and lift the piston in the carb up and let is drop.
It should raise evenly with finger pressure and drop back with an audible clonk.

[Morris_Jay]

Hi all,

Mrs morris_Jay here, He spoke to a morris minor company in devon and he advised me to there was a brake light switch thing (unsure of the name) in the engine bay. He unplugged it and he could then use the brake without it cutting out. Downside is this thing needs replacing as if he an use the brakes he has no lights (if its unplugged), if he has lights on he cant use the brakes (plugged in). So this thing needs replacing.

bmcecosse: It happened whether idling or moving, didnt matter what you were doing as soon as you put your foot on the brake the car would cut out.

Markyb: checked the air system seems fine, although saying that there was a theory that it was something to do with this short as it wasnt an obvious sucking/airy sound but we thought it was airy/sucking as it was such an unusual sound. The problem is we have found no-one else with this problem so not really sure.

[bmcecosse]

So - you are now saying that using the brake lights causes a short circuit in the electrical system - and that's what's causing it to cut out ??????????????? Sounds HIGHLY UNLIKELY to me! The brake light circuit is fused - any short circuit (unless a nail is being used instead of a fuse ??) will just blow the fuse. However - it's only two minutes work to change the switch - if done quickly/carefully there will be minimal loss of fluid (catch it with a rag wound around) - and no need to bleed the brakes. But - even IF it IS a short circuit - it's very unlikely to be the switch that is the problem - it's far more likely to be somewhere downstream towards the lights. And can ONLY cause this IF the fuse has been by-passed - or replaced with a nail! So - do look closely at your fuses !! With the ignition ON - touch the two wires together - what happens ? Do the brake lights come on ?? Is there a spark ? ? Does the 'sucky' noise happen - and if so - where is it coming from ??