Checked for boost leaks today.

[nobananas]

....mainly because I was bored but also to test a doo-dah that I had knocked up to attach my airline to. Large amount of hissing from underside of intercooler which was just the oil drain which when blocked off showed the intercooler was sound (which was a surprise). Some hissing from the re-circ valve which I assume wouldn't be a problem when under actual boost as there will be equal pressure both sides, a little hissing from the servo pipe join into the servo (not sure if that's right but can't see any sort of one way valve in the pipework). The more worrying one was some leaking at around 1 bar from the charcoal canister. Am I right in saying that there is a one way valve in the pipework to the inlet manifold and this is probably the cause of the leak as the canister is only supposed to be purged under vacuum conditions ( controlled by a solonoid valve in the same pipework) and the one way valve is there to prevent positive pressure acting on the canister ?

[TenaciousC]

A most admirable quest! - and thought provoking - hence the stunned silence your post received.

I would have thought that all leaks in this system are not welcome, and would ultimately cause fuel cut at lower boost pressure than is normal (I'm sure I have a leak hence my interest in this).

I'm fairly sure the brake servo shouldn't leak at all (under vacuum or positive pressure).

With respect to the carbon canister valve, again a leak at 1 bar sounds bad. So this needs to be traced.

Out of interest, how did you perform the pressurisation of the system? I would love to know so I can perform same test!

Cheers

C

[cherry1809]

Good idea! Beats trying to persuade my brother to sit under the bonnet whilst I hoof it up the road. Lol.

[nobananas]

A most admirable quest! - and thought provoking - hence the stunned silence your post received.

I would have thought that all leaks in this system are not welcome, and would ultimately cause fuel cut at lower boost pressure than is normal (I'm sure I have a leak hence my interest in this).

I'm fairly sure the brake servo shouldn't leak at all (under vacuum or positive pressure).

With respect to the carbon canister valve, again a leak at 1 bar sounds bad. So this needs to be traced.

Out of interest, how did you perform the pressurisation of the system? I would love to know so I can perform same test!

Cheers

C

Basically I made a plug that would fit into the rubber pipe that's joined to the boost pipe that comes across the top of the engine from the turbo. I could have plugged into it at the short pipe directly from the turbo but couldn't see the point as there was unlikely to be an issue in the metal pipe over the engine. The plug has a hole drilled in the centre and is fitted with a standard tubeless tyre valve robbed from an old wheel in the garage. Then just a case of hooking it up to my compressor with a tyre inflater between the two. I did fit a boost gauge to the vac tree just to be sure I didn't over do it !. I isolated the intercooler at one stage simply by jamming a wd40 tin in the boost pipe coming from the IC and doing up the clips tight so I could just presurise it and nowt else, not very high tech but it worked, I will have to make up another blanking plug at some time ! I would think that you could use a tyre inflator type compressor (12v) if you don't have workshop air but the amount of noise they make would make tracing the leak more tricky or you could use an inflated spare tyre with a suitable hose between it and the plug with the tyre acting as a compressor tank, that should work !

[BruceT]

I have one of these also, but no air compressor!

[cherry1809]

I would think that you could use a tyre inflator type compressor (12v) if you don't have workshop air but the amount of noise they make would make tracing the leak more tricky

Wouldn't be too bad. You could pressurise the system, And it should hold the air when you turn off the compressor. If it doesn't you've got a fairly major leak anyway :D

[merc85]

Hi any pic's of the tyre valve moded to fit the pipe?? would be ace

[nobananas]

Wouldn't be too bad. You could pressurise the system, And it should hold the air when you turn off the compressor. If it doesn't you've got a fairly major leak anyway :D

Trouble is I don't think a small tyre inflator type compressor would keep up/overcome even a very small leak (like the one that the oil drain in the IC creates), I just don't think it would create enough air volume. But a spare tyre with 60 psi in it connected with a tube with a shrader type airline connector on each end should have plenty of volume.

[cherry1809]

But a spare tyre with 60 psi in it connected with a tube with a shrader type airline connector on each end should have plenty of volume.

Lol, Reminds me of the washer jets I had on a VW camper. Run a pipe in from the spare on the front, Pressurise the washer bottle and hey ho. :D

[Dangerous Dave]

Large amount of hissing from underside of intercooler which was just the oil drain which when blocked off showed the intercooler was sound (which was a surprise). Some hissing from the re-circ valve which I assume wouldn't be a problem when under actual boost as there will be equal pressure both sides, a little hissing from the servo pipe join into the servo (not sure if that's right but can't see any sort of one way valve in the pipework). The more worrying one was some leaking at around 1 bar from the charcoal canister. Am I right in saying that there is a one way valve in the pipework to the inlet manifold and this is probably the cause of the leak as the canister is only supposed to be purged under vacuum conditions ( controlled by a solonoid valve in the same pipework) and the one way valve is there to prevent positive pressure acting on the canister ?
I got the hissing from the intercooler too, and just gaffa taped it up for test purposes.

Not sure about the servo.

The one way valves on the charcoal system were buggered on my engine too, and unfortunately they were about £42 for two of them from Rufe! So I bought a couple of one way metal fuel valves off ebay for £4. The one way valve should be inline right after the pipe comes of the inlet manifold

[nobananas]

I got the hissing from the intercooler too, and just gaffa taped it up for test purposes.

Not sure about the servo.

The one way valves on the charcoal system were buggered on my engine too, and unfortunately they were about £42 for two of them from Rufe! So I bought a couple of one way metal fuel valves off ebay for £4. The one way valve should be inline right after the pipe comes of the inlet manifold

I'd been looking at the same valves on ebay too bomb, out of interest do you remember what the internal diameter of the canister hose is as I didn't think to measure it when I had it apart yesterday. I was thinking of getting one for the servo too as they are usually fitted on other makes, don't know why there isn't one on the Volvo.

[Dangerous Dave]

The valves I got were for 6mm ID piping, same as these (probably the same seller, I can't remember), these are the cheaper ones, but others seem to be selling for double or triple the price for the same item.

http://cgi.ebay.co.uk/6mm-Fuel-Non-Return-Valve-oneway-petrol-diesel-freepost-/120679072091?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c1908815b

As for the Servo, I've just checked the info I have and the connector on the servo has a one way valve built into it.
http://i150.photobucket.com/albums/s101/bomb192uk/Servo.jpg

HTH

[nobananas]

The valves I got were for 6mm ID piping, same as these (probably the same seller, I can't remember), these are the cheaper ones, but others seem to be selling for double or triple the price for the same item.

http://cgi.ebay.co.uk/6mm-Fuel-Non-Return-Valve-oneway-petrol-diesel-freepost-/120679072091?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item1c1908815b

As for the Servo, I've just checked the info I have and the connector on the servo has a one way valve built into it.
http://i150.photobucket.com/albums/s101/bomb192uk/Servo.jpg

HTH

Cheers bomb, they are the same valves I have been looking at just wasn't sure of the size, may get one for the servo also as the integral one obviously isn't working !. Makes me wonder now, the brakes on my T5 have never been terribly inspiring and have always lacked initial bite, if the non return valve on the servo is faulty and the servo is full of positive pressure when I lift off the gas and hit the brakes assumable there is going to be some 'lag' between the servo flipping from positive to negative pressure and giving full assistance hence lacking initial bite ! (or I might be just seeing problems where there are none lol !). I can see me having to measure the diameter of the servo hose as well now, unless of course you know that too ?

[Dangerous Dave]

I can see me having to measure the diameter of the servo hose as well now, unless of course you know that too ?
Sorry bud, don't know that one.

[nobananas]

Sorry bud, don't know that one.

I dunno, call yourself a Volvo expert ! lol !

[Dangerous Dave]

LOL, I was gonna pop out and have a look, but couldn't find my torch :(

Am going to look in the morning anyway as what you've said about it leaking its worth checking on.

[nobananas]

LOL, I was gonna pop out and have a look, but couldn't find my torch :(

Am going to look in the morning anyway as what you've said about it leaking its worth checking on.

Think it's the standard 3/8 servo pipe (which is 9.5mm) so I have ordered a 6mm and a 3/8 non return valve off ebay. I'll let you know if the 3/8 one fits !

[stevie69]

im going to try this as my boost drops of pretty fast.could you make a plug and take your dump valve of and stick it in there to pressurise the system?or is that nowhere near the right place?

[nobananas]

im going to try this as my boost drops of pretty fast.could you make a plug and take your dump valve of and stick it in there to pressurise the system?or is that nowhere near the right place?

No that should be okay, anywhere in the pressure side of the pipework should be fine. The only downside is that you are removing the ability to test the dump-valve for leakage.

[stevie69]

cheers.maybe have a go tommorow.

[nobananas]

cheers.maybe have a go tommorow.

Just thinking actually, you will have to block off the pipe work somewhere between the turbo and the intercooler otherwise you will loose the pressure through the turbo (sorry didn't completely think it through !)

[Dangerous Dave]

You can undo the intake pipe to the turbo and block up the turbo inlet. That way you can test the bypass valve too.

Just thinking NB, I had a leak on my CBV too. I read on another forum that they leak where the diaphragm seals against the turbo housing. I took mine off, cleaned it and modified the metal housing to seal tighter against the turbo. It seemed to work ok

[nobananas]

You can undo the intake pipe to the turbo and block up the turbo inlet. That way you can test the bypass valve too.

Just thinking NB, I had a leak on my CBV too. I read on another forum that they leak where the diaphragm seals against the turbo housing. I took mine off, cleaned it and modified the metal housing to seal tighter against the turbo. It seemed to work ok

That may be where mine was leaking from too, i could hear it but couldn't tell whether it was leaking out or leaking in if that make sense !