DAF CLUB OF AMERICA - Vacuum Valve Problems ?

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Dec 28, 2009, 10:06pm

DAF CLUB OF AMERICA :: Tech Toolbox :: TROUBLESHOOTING THE DAF :: Vacuum Valve Problems ?

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Topic: Vacuum Valve Problems ? (Read 25 times)

THE BEAR
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The DAF Doctor

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Vacuum Valve Problems ?
« Thread Started on Sept 9, 2009, 6:17am »

The DAF Vacuum systems are in intregal part of the drive system and needs to be maintained...no Vacuum=No drive

I'll start with the Valve which was commonly used on the 44-66 DAFs.

[image]

As you can see there are quite a few pieces & parts in the newer valve that can screw up. "O" rings need to be in top condition for full vacuum. Still-a fairly simple part to work on.

John

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DCA DIRECTOR
*1962 DAF 750 Pick-Up (2x) *1962 DAF Daffodil (2x)*1966 DAF Daffodil Cabriolet *1976 DAF 46 Sedan*
DAF="Dutch Automatic Ferrari"

dafman
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Re: Vacuum Valve Problems ?
« Reply #1 on Sept 12, 2009, 9:44am »

How exactly does the Brake Vacuum work on a 31? It is rusted so bad to the firewall on the 31 here I can't even get it off! Is that something I should look into reworking? Would it be necessary to take it off the firewall to rework it or can I leave it right on there?

Is there any other parts you recommend rebuilding too? I just seen your Fuel Pump post... The Carburetor sounds like a good idea too. I would probably do all the rebuilds and stuff when I'm ready to put it all back in though too but still nice to think ahead right.

Vince

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1964 DAF Daffodil 31 / 1940 GMC Flatbed

THE BEAR
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Re: Vacuum Valve Problems ?
« Reply #2 on Sept 12, 2009, 6:04pm »

Well Vince...my recommendation would be a resounding YES.

Your 31 sat for so long chances are the O-rings in the Vacuum Valve have rotted or at least become super hard.
I would be best to get her off the firewall and do a rebuild. Without this little Valve you have no control over the Variomatic RPMs or even idle speed on the motor.

John

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DCA DIRECTOR
*1962 DAF 750 Pick-Up (2x) *1962 DAF Daffodil (2x)*1966 DAF Daffodil Cabriolet *1976 DAF 46 Sedan*
DAF="Dutch Automatic Ferrari"

THE BEAR
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The DAF Doctor

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Location: Mt. Tabor, Vermont USA

Re: Vacuum Valve Problems ?
« Reply #3 on Sept 12, 2009, 6:39pm »

Here is parts breakdown of the earlier styles of Vacuum Valves.
As you can see there is a lot more to the earlier styles, so more can go wrong with them.

[image]

This is the first style used on the DAF 600-DAF 31. This one is all metal.

[image]

This is the second style used on the DAF 31-DAF 33. This Valve has a plastic reservoir.

As you can see the earlier valves had an air reservoir chamber to store vacuum for the "Hill Brake" system (an early form of Jake Brakes used on trucks today)

Rebuilding is highly recommended if they have been sitting long.

John

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DCA DIRECTOR
*1962 DAF 750 Pick-Up (2x) *1962 DAF Daffodil (2x)*1966 DAF Daffodil Cabriolet *1976 DAF 46 Sedan*
DAF="Dutch Automatic Ferrari"

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