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I was going to hook up the vacuum wipers to my double acting fuel pump and noticed a very slight oil drip starting to form from the Out side port. I hooked the vacuum line straight from the manifold and the wiper worked great. When I plumped the line to the manifold & fuel pump it had a harder time sweeping. The fuel pump isn't all that old, but seeing a bit of oil can't be great. Can anyone confirm my fear of a bad pump? Thanks

I read that double action fuel pumps are prone to fail prematurely. Not sure about that, but I'm just going to get the regular type and run the wipers from the manifold only.

I installed a double action pump in my 49 about seven years ago. It's still working fine and I'm transferring it to the 235 that's replacing the tired old 216. I'm installing a PCV system on the 235 so the vacuum boost will probably be helpful.

My truck had a 6 volt auxiliary vacuum pump on the firewall when I got it. It had been disconnected long ago and I didn't bother trying it out. Maybe there's a 12 volt version out there somewhere but switching to electric wipers would probably make more sense. That's my plan when the old vacuum wiper motor gives up the ghost.

I put in a NOS AC fuel pump and now the truck lacks power. Not sure if it's a coincidence or not. I'm going to replace fuel filter then check fuel flow from pump. I've checked timing but not valves yet. I wonder if being a NOS could have something to do with it. Can anything happen sitting on a shelf for 40 years??

I put in a NOS AC fuel pump and now the truck lacks power. Not sure if it's a coincidence or not. I'm going to replace fuel filter then check fuel flow from pump. I've checked timing but not valves yet. I wonder if being a NOS could have something to do with it. Can anything happen sitting on a shelf for 40 years??

Rubber bits in NOS parts can be suspect, just from age. Check valves and diaphragm may be degraded. If it had been in service longer, then E10 might be a suspected culprit for damaging the diaphragm in NOS fuel pumps, as well, but unlikely on first few runs.

Absolutely something can happen. The diaphragm can dry out and crack. When you exposed it to the ethanol laced junk that passes as gas these days could have easily degraded the diaphragm and/or the valves. Get a new pump. Don’t mess around. With a bad diaphragm, you could be pumping fuel into your crankcase. Not what you want. In fact, if the oil smells like gas, you should change the oil no matter how new it may be.

Checked fuel delivery to carb and it filled a container very quickly. My next suspect is the accelerator pump. I noticed in the cutaway diagram of the Carter updraft diagram there is a spring in the pump. I feel no real resistance when I flip the pump down. Shouldn't I get a recoil from the spring? Thank you in advance for any knowledge and advice offered.

The van idles very well, only when I need power for climbing hills or when I need speed the power just isn't there. I use Langdons HEI and wondering if the advance is not working.

I cleaned out the carb with mineral spirits and advanced the timing a bit and seems to run better. I put on a different manifold earlier & thought I had a vacuum leak between the intake and exhaust but I tested with propane and smoke & I didn't hear/see anything. I think I hear a hissing noise on acceleration, but it could just be the engine. Hard to know if your doing it right sometimes.

What kind of air cleaner are you running?

I took out the NOS AC fuel pump and put in a modern Carter pump. Now it wont even start. No fuel leaving the pump at all. I noticed the pump arm on the original dual action pump extends 1/8 further out than the AC. I have not removed the Carter but it must be shorter still, as it won't pump anything at all. I guess I'll try building up the arm a bit.

Dragsix, it is a nos Fram press on air cleaner.