Hi guys,
TW series 2 making a air woosh sound when brake pedal is pressed.Sound seems to be coming from under drivers dash.I think it has something to do with booster.Is there a line or something which may be leaking or is booster gone?
Anyone have this happen and boosters expensive to fix?
Any ideas would be much appreciated .Thanks guys

sounds like the booster is gone.
Remove and replace with another one.

Yep thats what I thought.Now I just hope they still have them at our local (country)outlets and price isn't rediculous.Was hoping maybe a known hose or valve stuffed up.Thanks Old4fg.

Watching this thread as mine has been doing it for a while, didn't suspect anything wrong but perhaps the braking isn't quite as good as it should be. Will still break really hard if I stamp it though

wow we've gone straight to replacement booster hahaha. The brake booster get's all of it's power from a main vac line on the back of the intake manifold. On my old TE back in the day it had a crack in the hose at the booster end which caused an issue similar to this. After replacing the hose I never had an issue again.

I suggest starting it up and having a listen and feel around. If it's as severe as you say it should be obvious where the leak is. Otherwise spraying some brake cleaner / carby cleaner in to certain locations will reveal where the issue is. It sounds like a big vac leak.

If it really is the booster there are plenty on eBay.

TW series 2 making a air woosh sound when brake pedal is pressed.Sound seems to be coming from under drivers dash.I think it has something to do with booster.

I think atmospheric air enters the booster inside the cabin through a filter located on the end of the rod the brake pedal moves when you press it.
Never heard any noises from one though, but if your brakes are ok and the booster is holding pressure, nothing to worry about.

Testing booster:
Engine off, after running it for a few minutes:
Press brake pedal, should be normal height. Release and push again. After a few repeats, pedal should be high and hard to push.
Hold foot on brake, start engine. Pedal should move down a fair bit to where it is normally when you drive.

If the pedal is hard and high all the time, look for air leaks in the manifold to booster hose under the bonnet, and check the one way valve between hose and booster.
Boosters can fail if the membrane separating vacuum and normal air pressure inside it develops a tear, but you would have a high and hard pedal all the time.

Thanks Neo and MadMax.Booster seems to work but loses power with repeated pumps,big leak somewhere.Revs are also rising when brake is pushed and held.Now to find the leak,air sound in cab is coming straight from rod and piston behind brake pedal.That hose in engine bay looks suss,not perished but it must cop a lot of heat there and looks it . Hopefully I find leak in hose or valve.

If the hose off the manifold is leaking you will hear it when car is running. I lost all brakes one day which was rather scary and when i opened the bonnet the engine was hissing at me. Turned out the hose off the manifold to the booster had come off.

Hmmm you guys sure this noise isnt normal and expected? If I pump my brake with the engine running I can hear it whooshing. Don't notice it when driving normally, but if I'm at the lights or parked or w/e and start pushing on the brake it makes that sound. But only 'as' I'm pushing it through its stroke, no sound if I just hold the brake
If engine is off and I pump the brake a few times it feels high and hard with very little braking power, if I hold my foot on the brake and start the engine, the pedal moves in further as expected

I asked someone today with a Magna if theirs ever made a whooshing sound, he said nope but I double checked by starting his car and sure enough exact same sound, brake pedal feels identical to mine. However he hasn't noticed detrimental brake performance over time

So....... I'm confused? I guess it's possible we both have a minor issue but it seems fine to me? Is it worth looking into further?

Hmmm you guys sure this noise isnt normal and expected? I guess it's possible we both have a minor issue but it seems fine to me? Is it worth looking into further?

I'd be interested to know the outcome of this as I have exactly the same issue/symptoms as you.

Thanks Neo and MadMax.Booster seems to work but loses power with repeated pumps,big leak somewhere.Revs are also rising when brake is pushed and held.Now to find the leak,air sound in cab is coming straight from rod and piston behind brake pedal.That hose in engine bay looks suss,not perished but it must cop a lot of heat there and looks it . Hopefully I find leak in hose or valve.

SO loses power with engine running or engine off........