Hissssssssing brake servo

When putting new glow plugs in last week, we noticed a very slight hissing sound coming, (we think), from the brake servo.
Amazed we heard it at all cos of engine noise.
We thought we could see a pinprick hole in the casing but not sure, weather was awful so didnt look long.
My brakes have always been a bit spongy in emergency stop situations, and never have locked no matter how hard I try.
I will be looking to change it, and have a spare that came with the Landy, just dont know how good it is.
My question is, is that small hole able to effect my brakes as described, and secondly is it a full sudden brake failure waiting to happen?
Dont wanna muck about re brakes.
Oh, and "Merry Christmas" all.

The brake pedal will go solid without the vaccuum created by the servo.

did the hissing stop when you covered the hole with yer grubby pie holders?

Had a similar issue on a Td5 90 we had a short while ago (and perhaps beginning to surface on the 110 ).

In short - yes it will cause a problem as the servo is meant to be a vacuum (rather than a pressurised vessel). Unless you have ABS I would have said that on a tarmac surface you should be able to get all four wheels to lock up.

A simple test which I was shown to test whether the servo is working is to pump the brakes up while the engine is off (the pedal should go hard) then with your foot on the pedal turn on the engine, if the servo is working properly then you'll feel the pedal collapse as the servo builds up the vacuum.

Cheers guys.
i will indeed try those two things and see what I get.