Bosch recirc valve

[cheys03]

I've bought a used VW/Audi recirv valve, part number 034 145 710 C which I believe is reasonably commonly used with G40 turbo conversions. It's the same as in the photo below pinched from an American Audi site.



The valve doesn't appear to operate as I would expect, but would like to make sure I'm not misunderstanding the valve before condemning it...

If I suck on the vacuum line then it will suck air through the 'pressurized air dump in'. When connecting the valve to a vacuum line on my engine it won't open, but when the valve is gently pushed open through 'pressurized air dump out' the vacuum will hold the valve open.

I suspect the diaphram between the vacuum side and the boost side of the valve is shot, but looking for confirmation please chaps. Cheers.

[cheys03]

Yup, fooked seal





Looks like it's torn (no I've not sawn into it!) where it is folded and sealed under the cap. Damn nuisance.

[Robin]

these dump valves are crap, they don't last long as the rubber easily splits, i have about 5 of them in the boot of the car as spares, they don't last long with 22psi of boosts!

[cheys03]

Duly noted! 

[hayesey]

yeah I had one pop on me half way through a track day.  Ran the rest of the day with a screwdriver handle shoved into the dump valve hole

[vwmk3jon]

Wont buy one of those then! Lol

[Doc J]

My opinion - GReddy Type S insted of the Bosch one - good recirc dump valve, hard to appear damage on it



Negatives - may be too big valve diameter (35mm insted of the 24mm in Bosch one) and the price of it!

[hayesey]

Tial make some nice ones too.  Although I'm currently using a right chavvy one that a mate found in his shed, I think it was used on an escort rs turbo, it's anodised bright blue and makes a right racket but it's not blown up yet.  I might save some pennies for a nice Tial one though!