Fuel pump questions

[Blitz]

Chimesickle,

No offense taken... at all.

Yes that is to be done immediately.

I did wiggle all the wires at the pump ( a Military packard fitting) and at the switch also.

I will go through the entire circuit when I go back out there.

No offense taken at all and thanks for the reply also.


Just as a history, those that have read some of my posts ...
I keep all of the wiring and electrical pretty "top notch" in the truck.. and that is usually all I ever "improve" or check or add to anymore...
making all the light switches for the spots match, improving connectors as I can...

i'm always waterproofing or conduit wrapping wires and adding fuses for accessories...

maybe I knocked something lose...
Its very possible..
but its been a few weeks since I did any of that and this just started today.


I will triple check it for sure, before pulling it.

just honestly ... I need a shower and some sleep,
before the gas fumes finish me off pulling it.

combat pay around here sux.

[chimesickle]

Ok, thanks for the thoughtful response. I have to apologize for not reading your previous posts on other threads. Its been a while since I logged in here. I tend to come here when I need answers. I try to help people but I am not a good mechanic and no expert on these vehicles either. I have had the truck for 9 years I think, but still have a lot to learn.
I assume you have a 24 volt circuit tester. A volt meter is better, but not always neccessary to find problems.
So I guess your problem is not electrical. I have a backup 24 volt fuel pump located near the tank also, for emergencies. I bought a couple spare mechanical fuel pumps (cheap) on ebay shortly after I got the truck because of failures. I try to keep a couple feet of 5/16 fuel line for emergencies. I even have had to use it to pump fuel out of a 5 gallon Jerry can.

[Blitz]

Lol... no apology required.

Dont sweat the small stuff...
There are a lot of good posts here and there is no way to stay on top of them all..

believe me, I have tried... every day for months on end and I missed a LOT of good info.



It really could be electrical.
I will get to check it today, since I had a night of rest ... finally.

It will be the first thing I check, but I want to check the entire circuit at once.
( Its fed from the master switch, to the super secret switch, then to the pump )
and it "could also" be the ground, as you pointed out. Or the switch itself.

Yeah, I understand about the failure prone items.
I really like to carry everything I need IN the truck
and I even went as far as putting the proper tools with each item, from my old rusty stock of abused tools.

I think it was Barrman that recommended carrying a barbed brass "insider" fuel line fitting, as well... and I have two or three of those and about 6 feet of 3/8 fuel line for just such an emergency... and a spare 12 volt pump ready to rock n roll.

such small efforts can really save ya on the side of the road.

If I cant find a rebuild kit for the Bendix again ( should have saved that info better )
I will probably just get a new Facet pump that matches it, and stay 24 volts for now.

Then I will have more time to rebuild the Bendix.

I will check everything today, pull it, blow the lines , new fuel filter before the pump and put the 12 volt version on for now...
just to keep it rolling.

As I tear into it, I will post the autopsy report and maybe Frankenstein it back to life.

Sounds like "its a good thing I'm doing this NOW "

Universal timing...

I have learned to listen to it, and change my other plans immediately, when called to do so.

[sm610user]

I did cap off my mechanical pump. I was having issues on our mountain trails in VA. I went to a carter rotary vane pump in 24V. mounted near tank and set it up to disconnect the line so I could fill a gas can from the tank

http://www.summitracing.com/parts/CRT-P4603HD/

pump makes a little noise but solved all of my issues

[Blitz]

That is NOT a Bad Pump You posted.
Its as rotary vane model, similar to the pump I have on my "parts truck"

And Yes, they are loud...

I considered that route... and I really "still should" so both trucks match.

The only issue I have read about is that they need to have to "pull" of the engine vacuum while the pump is running.
I also dont want it hanging down under the frame... But I could get around that with new mounting holes.

"Due to the positive displacement design, the rotary vane pump will not allow a pull-through arrangement and is designed to run while engine is running"
not too much of any problem...

Looking for a pic on the one on my parts truck... Yes... loud...
but has served me well so far.


[IMG][/IMG]



The one I just pulled is a Facet, in fact.
I could not see the label while it was installed.

I checked all of my voltages, and everything is good to the switch, out of the switch and to the pump... 24.75 volts, engine off.

I hooked a vacuum pump to the tank, with a gallon jug to catch the gas...
No problems with flow...
I does not seem anything is sticking to the sock inside.

I will blow the line with low psi anyway, when I install the other pump.

The Facet Number of this Pump is 480564, and is 24 volts negative ground.
Max Psi is 5.0 psi, minimum is 4.0, 32 gallons per minute, impulse drive.
1/4 inch 18 pitch threaded fittings, and mine has two 90 degree threaded barbs for the hoses.
12 to 24 inch dry lift, Positive backflow prevention, ( anti siphon ), internal 74 micron filter, built in magnet to collect any metal particles, self priming, and corrosion resistant to 100 hours of Salt water immersion.
operating range from -40 deg to 180 deg F.
Conforms to MIL SPEC 461-D.
all Made in the USA.

[IMG][/IMG]

I pulled it apart to find out what I can see....
I wanted to look up the price of a new one and see where I stand...

without shopping, it looks like 109 bucks...

http://www.yachtsupplydepot.com/mech...rod_23453.html



The only thing I found inside was a very small amount of very fine Corpus Christi beach sand, from the previous Owner : )

[IMG][/IMG]

The end gasket is a little cracked and worn...

Everything else looks ok mechanically...

[IMG][/IMG]

[IMG][/IMG]

[IMG][/IMG]

I will clean it all up good, put it all back together and run 24 volts to it and see what happens.

I suspect the electronics inside have given out, to be honest.
They are sealed inside, and inaccessible.

No further end user dis-assembly possible...

I left one small rubber washer inside the pump, under the solenoid shaft...
I saw no need to remove it and chance tearing it.

[IMG][/IMG]


The Facet Number of this Pump is 480564, and is 24 volts negative ground.

[Blitz]

50 Bucks on E bay... New..
Fits a Cessna, Piper Cherokee, and has the safety wires on it.

Mine has the label that says "not for aircraft use", but I'm gonna chance this one...

7 more available if anyone needs one.

http://www.ebay.com/itm/NEW-Aircraft...p2054897.l4275

[Blitz]

last update for me on this ...

cleaned the pump up, re assembled it... bench tested it...

click click click... sounded stronger than ever...

Re installed it on to the truck...
Put a few new electrical connectors on it and a few zip ties here and there...

Turned it on, let it prime and burp...
checked for leaks..
All A- ok.

fired up the engine...

Idles fine... but the fuel PSI gauge only shows 3 PSI.

Obviously , I made some sort of improvement... but it cannot be trusted As- Is.

I ordered the Cessna Unit and will install that.

I will re visit the Facet site and try to get a rebuild Kit for this one... and give it one more go.
http://www.facet-purolator.com/

A member here earlier mentioned a fuel cut out safety switch,wired to the oil pressure switch..

I think I'm gonna do that...
as it really seems like a necessity.

More research... but I dont want fuel pumping , should the engine stop.

Will require a "Prime" momentary over ride switch...

Lol .... or a Cessna "Prime Bulb" control assembly ...

[Blitz]

Does anyone have any practical ideas for installing a fuel pump cut out switch ?

I was thinking, run off of the oil pressure...
But something in 24 volt.

Like a "TEE" fitting off of the block, where the Oil PSI sending unit lives, then install another "24 volt sending unit", that cuts power at the terminals at about 5 PSI Oil , or lower.


It needs to be 24 volt... as the pump and truck are.

It needs to be "normally closed" above say 5 psi, and "open" below 5 psi.. ( or 10 would work too )

Any ideas on this ?

I want something that will cut the power to the Fuel Pump, should the engine shut off, and there is no Oil pressure.

I know GM make a 12 volt version of this switch...

24 volts run to it may "arc it" into either open or closed...

Just want to come up with something along these lines...

I think modern vehicles use a kinetic switch that senses impact...

I will start a new thread about this as well, But I think it belongs in this post also.

New thread here:

http://www.m715zone.com/vb/showthrea...362#post249362

[Barrman]

Use a relay. You have 12 volts on the truck for your ignition. Just tie that into a relay the pressure swith can be the ground for. The other side of the relay can be the 24 volt supply to the fuel pump.

[chimesickle]

Here I go again, just jumping in without reading previous posts. I may have to delete this.
I was just thinking the brake light switch is 24 volts, normally open, then closed under pressure. But I have no idea what the trigger pressure is. I have no idea if it is possible to plumb it in nicely. Too may reducers, and adapters would be counter productive.
Forgive me please for such a silly and outlandish idea