me yet again,

Just wondering when you rev your car and you can here a sound like water running though a pipe (like air and water) coming through from the dashboard is that normal.

Also, since my stiff brakes were fixed (a block non-return valve?) the brakes hiss, it stops when I press them and gets louder when you release the brakes, and then goes back to a background hiss... Again, is this normal, why is it hissing??

Hi Chris,

Is the water and air sound present with the fan off too?
Are there any wet patches on the carpet?
Is the radiator loosing any water – remember - check only when cold.

The brakes – hissing isn’t normal!
Can’t you take it back? Sounds like the rubber vacuum advance hose has a leak. I replaced mine on the old 903 UNO. The pipe was about £7 – a new non-return valve about £1.

I just checked on the 1.0 IE – this pipe starts under the Injector’s N/S electrical connector block, and runs round the back of the engine to behind the brake fluid reservoir, into a white non return valve, mounted on the servo. The pipe is thinner than on the 903. If it is deteriorating, replace it. TBH it sounds like someone may have cut out a bad bit, used the wrong pipe, or fitted it badly.

hi louie,

Thanks for the info on the brakes... I'll have to see to it when i get a chance.

The water and air through pipe sound also occurs when the vehicle is stationary... I was wondering whether I could here the petrol being pushed through a pipe to the engine or something..
It only happens when you rev up as when pulling away (it's more obvious when I pull away quickly) or giving it a good rev when stationary.

It's hard to explain the noise it's like squirting water in a pipe that has a little air trapped in it... it's not like sucking at an empty drink. it's higher pitched and perhaps like a squelching sound... but it's not squelching, if you know what i mean!?!!?!?!?!?

Hi chrissmith,
i also had a similar problem with this water noise when i rev up (stationary or moving). Its the internal water circuit (sorry for any english mistakes) that brings water from the external radiator to the internal small radiator which is used to warm the air. Possibly it has some air inside that circuit that makes that noise. Many times i tried to take the air out of it, but sometimes after some time it happens again. Luckily the last time it was successfull.

You take the air out of the interior circuit with this procedure.
Turn the internal temperature control to HOT position. Turn on the engine until the ventilator starts working periodically so the engine is on working temperature.
Unscrew a little the plastic screw that is marked in the image.
When it comes out only water screw it again.

That's what i did and worked.

Hi Geom,

just a quick adiotional question, do you unscrew the screw with the engine on or off?

Thanks

chrissmith said:

Hi Geom,

just a quick adiotional question, do you unscrew the screw with the engine on or off?

Thanks

Click to expand...

The engine must be running idle in working temperature. Unscew it in small steps until water is coming out. Dont forget to turn the interior temperature switch to HOT.

Good description geom! Rep awarded as photo too

Might I add before you start the procedure, unscrew the bleed screw with engine cold and loosely tighten. I suggest this as the screw is more likely to brake when Hot, and will be under more pressure

Oh the fuel line runs under the Uno, so its doubtful you would here it.

BTW Nice Avatar Geom!

Regards all,

Thanks Louie

:woot: Your Welcome

Yes it is air in the coolant system. Nothing to worry abou though, but do as mentioned above. Turn heater to hot. Open the bleed valbe. Start engine. Wait until water starts "pippling" out. Then wait some more. Nothing to worry about spilling some coolant. Tighten when hot, and drive safely...

Is it the front brakes that hiss? If so, it can be worn brake discs. A slight groove might have developed over time, making the brake pads touch a bit. This sound will disappear under braking, and return after a while. Also nothing to worry about if it doesn't drive you mad. You could change the brake discs, and rub down the pads' "unevenness" and reinstall them if they aren't worn out.

Morten...

high morten,

the noise i hear for the front brakes makes the noise even when stationary, so could it still be the disc brakes?

chrissmith said:

high morten,

the noise i hear for the front brakes makes the noise even when stationary, so could it still be the disc brakes?

Click to expand...

Chris,

The hissing noise from the brakes might also be a faulty brake servo, or vacuum pipe connecting to the servo.

Might be an idea to have someone sitting in the car, with the engine running and applying the brakes while you have a listen under the bonnet to try and locate the source of the noise.

Chas

chrissmith said:

high morten,

the noise i hear for the front brakes makes the noise even when stationary, so could it still be the disc brakes?

Click to expand...

Actually, I don´t know... Sorry.

chrissmith,

The water-rushing noise is caused by air in the heater, as others said, but it may be accentuated by the heater valve not opening or closing fully.

The heater valve is located on the right-end of the heater radiator, under the dash. It is made of black- or white-coloured plastic, with a rubber hose running to it. There is a lever operated by a cable from the heater controls. First check that the lever is moving when you move the controls.

Then, if the heater valve is basically a rectangular shape, bear in mind that it may be jammed, because they seem prone to this. The later design was heart-shaped; a different design, but interchangeable.

So basically what I'm saying is that if the noise bothers you, check that the heater is turning on and off properly. You should be able to stop the noise by turning the heater off (or fully on) - the noise happens most when the heater is partly on. It is still nothing to worry about, however.

The brake hiss, though, is something to worry about, in my opinion. I reckon it will be the plastic fitting on the brake servo - worked loose, or split. A vacuum leak here will affect the running of the engine (especially idling) and of course there is the theoretical possibility of loosing the vacuum assistance to the brakes, which would be dangerous. Also check the pipe itself, it may have a split near the end fitting(s).

Thanks,
-Alex

Just wanted to add a quicky about the water rushing noise. If it's also a kind of bubbling sound, or gurgling, then it reminds me of the noise my first car made just before the head gasket went. It's possible that Chris' car is about to blow it's gasket - water starts disappearing from the cooling system to be replaced by air hence the noise. Check the oil and water levels for signs of this, and also check the oil filler cap for obvious signs of 'mayonaise'.

I agree with Alex that losing the vacuum assistance is something to worry about, though it is worth bearing in mind that even if the servo fails completely you will still have brakes. Albeit without servo assistance. You would have to push MUCH harder on the brake pedal to make them work.

I'd get these two problems investigated as soon as possible...

Chas