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| | | | Joined: May 2003 Posts: 183 'Bolter | | 'Bolter Joined: May 2003 Posts: 183 | I installed one of those dual diaphragm fuel pumps in hopes of making my vacuum wipers work better on my 1952 1/2 ton with a 216 engine. There is now a knocking sound coming from the fuel pump. You can also feel the knock when you touch the vacuum lines. The knock goes away when you turn the wipers on. I figured I didn't have the bolts that attach the pump to the engine tight enough so I took it to my local mechanic to have them tightened by a professional. He put some thread lock on the bolts and tightened them as much as he dared. But it still knocks. And, sadly, my wipers don't work any better than they did before. I read several posts on hooking these things up, and I'm pretty sure I have the lines connected correctly. Do you think I have a bad pump? Any suggestions would be appreciated.
My dad always told me, "Don't force it, get a bigger hammer".
| | | | | Joined: Jul 2013 Posts: 863 Shop Shark | | Shop Shark Joined: Jul 2013 Posts: 863 | Did you make sure the pump arm is located on the camshaft eccentric lobe properly? The flat on the pump arm must lay against the cam eccentric lobe. Could be internal to the pump. I would check to make sure I have the arm seated properly first. If that doesn't fix the knocking then I would return the pump for another one. The diagram for the proper line hookup is the shown in the Assembly Manual.
Tim
"Pay attention to the details! It ALWAYS pays off."
1949 Chevrolet 3100 Series 1/2 ton Pickup
1964 Chevrolet C10 (Ol' Yella) (SOLD)
1958 Chevrolet Biscayne 2 door (SOLD)
1970 VW Beetle
| | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | I put an AirTex or whatever the name is, double unit on my truck several years ago. It leaked gas around the housing rim no matter what I did. I got a replacement and it leaked gas and oil. Both were junk.
The vacuum unit only enhances the vacuum when the engine vacuum is really low, like at a wide throttle setting. The rest of the time the engine is drawing more vacuum through the pump. Also the pump is only useful at higher RPMs. If I remember correctly the pump by itself draws about 11 inches. | | | | | Joined: Feb 2004 Posts: 29,838 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,838 | Double action pumps have been a chronic problem for quite some time. The older ones have been sitting around in warehouses for years which makes the rubber parts deteriorate, and it seems that the more recent "rebuilt" units have a huge failure rate right out of the box. Keep trying until you find a good one.
Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln
Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway
Love your enemies and drive 'em nuts!
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