C3: Diverter valve vacuum hose connection

[Matthew S.]

I have a question about how a vacuum hose connects to the diverter valve. My car has all the mechanical smog equipment (smog pump, diverter valve, manifold trees, etc.) installed but none of the vacuum equipment (hoses, solenoids) is installed. On the back of the diverter valve where the vacuum hose would be attached there's a hole but there's no nipple or anything that a hose would connect to. I checked the hole closely and it doesn't appear that anything was cut off. Is there soemthing in the end of the hose that pushes into the hole in the diverter valve or is there some fitting that slides into the diverter valve hole and also into the vacuum line?

Thanks for your help - Matt

[Steve Wallach]

Re: C3: Diverter valve vacuum hose connection

I'm not sure if I'm thinking of the same thing you're describing, but I have a
68 427 / 435 with all the smog equipment also.
The hoses do connect with a small metal tube that pushes into some of the valves. Everything else either connects by the hoses pushing on and being clamped. What engine do you have? Carb/s?

Steve

[Matthew S.]

Re: C3: Diverter valve vacuum hose connection

Hi Steve,

I have a 72 LT-1. There's one vacuum hose that comes from the back of the diverter valve and goes to a T connector that splits it to the carb and to the TCS solenoid. I'm looking for how the vacuum hose is connected to the back of the diverter valve.

Thanks,

Matt

[Joe L.]

Re: C3: Diverter valve vacuum hose connection

Matt-----

The valve originally had a short piece of tubing that inserted into the hole in the die-cast body of the valve. This piece of tubing was an interference (press) fit in the valve body. Apparently, yours has become "dislodged" and is "missing in action". The connector was never sold seperatey. However, you should be able to obtain a short piece of the correct size tubing and press it into place. You want to make sure that you don't get too large of an OD tubing, though. If you do, when you press it in, you'll likely crack the valve body. You don't want to do that.

[steve wallach]

Re: C3: Diverter valve vacuum hose connection

I just double checked my old tri carb set up which I have sitting on a shelf.
There are three of these small tubes (on a tri carb set up) they simply press into the hole on the carb.

They have an enlarged end to hold the rubber tubing on I guess and the straight side of the tube presses into the carb.

These look to be gold cad plated or perhaps they are brass? I would think if you can find someone with a lot of carb parts, you can find these tubes. You might try Chicago Corvette, they do a ton of carb work and I have been satisfied so far.

Good luck,

Steve

[Matthew S.]

Re: C3: Diverter valve vacuum hose connection

Thanks Joe - I'll find a piece of hard tubing and GENTLY put it in the valve.

[steve wallach]

Re: C3: Diverter valve vacuum hose connection

Ok, if you check e-bay, you may be able to get a diverter valve with the tube in it for a few bucks. The tube appears to be the same size as the Holley press in carb tubing, but looks a little different.

Steve

[John H.]

Re: C3: Diverter valve vacuum hose connection

Matt -

You also want to make sure the diverter valve's vacuum diaphragm hasn't failed (most of them have), as it will become a massive vacuum leak. Also, when that diaphragm fails, the spring-loaded spool in the valve defaults to the open position, which will dump pump output into the manifolds 100% of the time, which will result in constant "popping" on overrun.

[Matthew S.]

Re: C3: Diverter valve vacuum hose connection

Thanks John - I do have some popping now so I suspect the diaphragm is shot but I'll be checking the whole system in a few weeks. Thanks for the tip. Matt