A story, and a warning to users of the Forge 007 diverter valve.

A nice man (who shall remain nameless for now, for reasons that will become apparent soon) drove my car last weekend, briefly. This man is very knowledgeable, and after about 50 yards in the car said to me "your diverter valve is broken" (OK so he used a colloquial term :P ). We removed it from the car, and he stuck a finger up its bottom and attempted to lift the piston. Nothing happened. He stuck a small screwdriver handle up it, and tried the same thing. Same result. So we took the lid off. We looked at the seals, and the spring, and the piston, and all looked normal. So we looked at another similar valve, and light dawned. The attached pictures tell the story.

The groove machined into the top is not big enough to allow the piston to slide up into it. The piston should have about 5mm of free movement, but mine had only about 0.1mm of play before it became jammed firmly against the top.

It's not really clear why this happened. I've contacted Forge, and like top chaps, they've sent me a new one free of charge (I'm sending the old one back to them for investigation). You can see the new one's lid on the right of the first picture. The other picture shows the body with the piston slightly raised out of the body, as it would be when venting.

So a little heads up for you. If you have one of these valves, and you are not absolutely sure, go out to your car and take it off, and check that its piston moves freely up and down. Alternatively take the top off and look at the groove - it should be about 44 mm in diameter. If it isn't, it doesn't work, and it could damage your engine. Having said that, to my embarrassment, this valve has been on both my cars, over the last nearly 2 years, and I never knew it wasn't working as designed, never having seen one that worked properly. But I thought you should know...

Ahhhh

All becomes clear!

Ooops - Bit of a QC issue there then.

Nice pictures though Nick.

checked this out and I can see the issue is the valve has the old ( now not made ) DVR valve top on the 007P base , looked at the assembly instructions/records that we used to use and I can see that the batches were assembled at the same time and a simple mistake has occured , a very isolated chance of this happening when the valve was made .....and no chance of it ever happening again as we dont make the DVR any more

Apologies for any problems

This was a while ago, and as I said in my post, I was sent a replacement very quickly. I have no beef with Forge.

Thanks for clarifying how it happened though, I've always wondered.

Do the valves go through any kind of test after assembly?

Weren't you having trouble with your car not running right a while back?

Would this have been part of the problem?