I am installing an electric priming pump at the fuel tank in my 5C. Just inside the fuel door. There are two copper lines side by side. The bigger one on the left looks to be 3/8" ID. The smaller one on the right looks like 1/4". I am assuming that the bigger one on the left is the supply, and the smaller one on the right is the return. In the engine compartment, the supply line is bigger than the return line.
Am I right?
Neither the maint. nor the parts manual are any help.
What would be a simple way to find out for sure? I have too many things apart right now to start the engine.
Somebody knows off hand?
JC
Just guessing but won't the return dump into the top of the tank? If so you'll be able to easily blow into it and there will be head pressure on the suction line.
Bob, are you saying that if I disconnect both lines at the tank and blow into the return line, fuel would come out the supply line? I could try that tomorrow. Also, if I blow into the supply line, I would have bubbles come up to the surface. The tank is full now, so it would be easy to see down the fill neck.
JC
It will be the 3/8 the fuel pump doesn't have a 1/4 suction line
No, what I meant was if you blow into a line that terminates at the bottom of the full tank there will be resistance whereas if you blow into one that is into the open top of the tank there won't be resistance. Make sure you know where your check valve is though before you try this trick because you shouldn't be able to blow backwards through it.
Yes, bigger is supply.
happy coaching!
buswarrior
Thanks guys for confirming what I suspected. I will double check by blowing into the lines tomorrow, thanks Bob. I will likely put the electric pump in line on the 3/8" one. I'll do a picture of the finished project.
JC
John it's good to see the electric primer pump idea has your Shod Nod of approval ;) ;D
All the Best! 8)
Van ;)
Run the engine for a while and feel the lines... the return will be hotter
Here it is. Simple installation, in line.
This is with the body panel back up. You can see the switch.
JC
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi582.photobucket.com%2Falbums%2Fss267%2Flostagainphoto%2FIMG_4243.jpg&hash=f9e273e8851b424784404762d567b3576b3104a7)
This one is with panel off. Just enough room for pump behind panel on the right.
JC
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi582.photobucket.com%2Falbums%2Fss267%2Flostagainphoto%2FIMG_4240.jpg&hash=7e17d10a24f8f8b8e281860eadb9847af27e3b8e)
Not going to work JC you left out the bypass I been told that for 20 years lol nice install
good luck
JC, is that a "pass through" pump? I mean, if you don't have it switched on (in the prime mode), does the engine fuel pump just draw fuel through it -- like it's not there? Would you mind posting where you got it, part number, etc.? Thanks, BH
I agree with Clifford, not enough plumbing there to warrant several valves in the mix either LOL! Nope it'll never work! ;D Nice and simple, good job JC!
Van
Draw-through pump - yes. works in-line while turned off - yes. Primes the system in a jiffy (mine took 15 seconds for initial start-up on a new engine) - yes.
I put mine in the engine compartment, in the main fuel line going to the primary fuel filter. It had no problem picking up fuel from the tank.
It is an Airtex E8131 External Fuel Pump, available many places, in different voltages, and rated for diesel fuel. It is made in USA, fwiw. http://www.airtexproducts.com/TSB/TSB-0108-01_ATX.pdf (http://www.airtexproducts.com/TSB/TSB-0108-01_ATX.pdf)
This really should be a sticky. Every time I post this I have to run out to the garage, get my spare pump, write down the number and google it to get the Airtex link. At least this time I managed to find the picture without having to take a new one... ::) ;D
Brian
Quote from: bevans6 on December 16, 2011, 04:45:49 AMDraw-through pump - yes. works in-line while turned off - yes. Primes the system in a jiffy (snip) Airtex E8131 External Fuel Pump, available many places, in different voltages, and rated for diesel fuel. (snip)
Thanks Brian, very useful. For all his stupid moves, Mr. Leyland saw fit to put a very effective primer lever on the O-680 engine fuel pump -- it's about the size of your thumb and it makes enough pressure (or suction depending on where you are in the system) to draw fuel through the filters and out through the fuel lines to the injectors so there's no "bleeding" if you run out of fuel, have a filter meltdown, etc. But it will sure be good to know that prime is right there with the touch of a button on that dark, rainy night when most of the breakdowns seem to occur.
Thanks for going to the trouble to post this. BH NC USA
Just to complicate things a little, ;D Brian, your picture shows both a 12 & 24 volt pump. There is a difference in psi. From the pdf file it looks like the one you used is the 24v pump? Does it come in 12v? JC, did you use the same pump? 12v or 24v, psi? ??? ;D ;D
You want to keep the priming pumps at low pressure around 5 to 20 pounds it won't hurt anything they make those up to 115 lbs psi
Nice to see the younger guys doing things that don't work lol you would not believe the heat I gotten over the years for that setup
good luck
I thought that the lower psi pump would work, but the main thing i was thinking about was depending on where i put one, i might have 12v easily available instead of 24v.
I bought the pumps at different times for different purposes. I use the 24v pump in the bus since being an MCI there is 24 volts everywhere. I have a spare because I lost the first one (found it as I was putting the new one in a safe place to store it while I waited for it to be it's time to get installed. the new safe place was the same as the safe place I put the first one so I wouldn't lose it. Yes, I am a "loser" ;D )
I bought the 12v one to pump solvent through my fuel rails to clean up and loosen up the injectors, which were sticky. I have a handy 12v power supply for such things, do I bought a 12 v pump. But it would be the right one for the GM guys with 12 volt power systems, so I put it in the picture too. On the link there is a different part number for the 12v pump. If you put that part number in google along with the words "fuel pump", it will give you many places to buy. I bought mine at Princess Auto.
Cheers, Brian
Been away on the road since yesterday, in a MacDonald's now with WiFi. The pump I installed is the Airtex E8131, at Princess Auto in Canada. It is the 24V. About 12 to 15 psi IIRC. Fuel will flow through when off. It has a one way check valve too. So it will be off 99.99 % of the time. I'll turn it on when I need to prime. Such as when I replace fuel filters. I thought having it at the fuel tank would be good in case there is a leak anywhere along the line. Anyway, a nice little winter project now off my list.
Merry Christmas everyone.
JC
Clifford, you sir are a bad influence on us youngster's Lol! ;D
Quote from: lostagain on December 16, 2011, 08:50:49 PMBeen away on the road since yesterday, in a MacDonald's now with WiFi. The pump I installed is the Airtex E8131, at Princess Auto in Canada. It is the 24V. About 12 to 15 psi IIRC. Fuel will flow through when off. It has a one way check valve too.
Thanks for that, JC. You are using the same pump that Brian is using. It's also the one that I'll go with, although I will need a 12V version.
Quote from: lostagain on December 16, 2011, 08:50:49 PMSo it will be off 99.99 % of the time. I'll turn it on when I need to prime. Such as when I replace fuel filters. I thought having it at the fuel tank would be good in case there is a leak anywhere along the line. Anyway, a nice little winter project now off my list.
Yes, any air leak in a fuel line will "break suction" and any pump (be it engine-mounted or electrical) will only suck air. If you have a leak in the fuel line between the electrical pump and the filters and fuel injector pump (or individual injectors or whatever your engine has), you'll get a fuel leak with the pump on. But at least it will be obvious and you've got a reasonable chance of putting a glop of Gorilla snot on it, covered with a piece of old bicycle inner tube and a hose clamp, and getting on to a place where you can make a permanent repair. The "obvious" thing is a big benefit too -- a tiny leak in a fuel line that only sees suction will make your life miserable; and they're d@mned hard to find.
Thanks again for the help.
Quote from: lostagain on December 16, 2011, 08:50:49 PMMerry Christmas everyone. JC
Merry Christmas to you, too!