Priming pump will not work!

[CMC1]

Been reading a loooong time, but this is my first post so bare with me. I done a search and found similar info, but no answer.

I have changed my fuel filter twice now and had the same problem both times. Unfortunately I ran out of fuel the other day and had the same problem.

On the filter changes, I can pump,pump,and pump, but no fuel. I've pumped it hundreds of times witn NO fuel. I finally pull the filter back off, fill and re-install. I still have trouble starting it, but can eventually get it started.

After running out of fuel, I put 5 gallons in and pumped my life away, for hours. Finally called a tow truck to take it to the house. Pulled the filter and not an ounce of fuel in the filter. I fill it re-install, pump, pump, pump (fuel comes out after filling the filter) and crank it till the batteries die. Let charge for a few hours and give it a go again. Finally it fires.

I realize it would harder after running out of fuel, but the pump is just not working. Has anybody had a pump simply not work?? I can hear it moving air and when I fill the filter it does spit out fuel, but I literally pumped for hours and no fuel in the filter??

thanks for any help and sorry about the length.

-Chad

[KompressorMan]

Are you opening the bleed port?

[DmaxMaverick]

Welcome to the forums!

Just bleeding is not enough. After it is bled, it needs to be "primed". Meaning, after it is bled, you need to pump it up to pressure so the low pressure pump on the engine mounted fuel pump will prime and expell the air. 10 or more pumps, or until you feel significant resistance is necessary.

The best method for bleeding:
With bleeder closed, and fuel cap removed, pump until resistance is felt. Open bleeder to vent air, then close. Repeat until only fuel comes out. Tighten the bleeder, then pump it up to pressure. The pump will handle any more air that might be present. The fuel cap is removed to minimize vacuum in the tank while priming. Don't forget to replace it.

If you are pumping with the bleeder open, it will take significantly more pumps, as it will draw air in with most of the return stroke of the pump. On some, it can take what seems like forever, and on some, it will take only a few pumps (don't have answer for that one). Some seem to be more sensitive than others.

Another method to speed the empty filter bleeding:
Remove the bleeder screw from the filter housing and have another person watch the hole. Use LOW shop air pressure to pressurize the fuel filler. Be patient and keep the air pressure below 5 PSI. When fuel comes out of the bleeder, tighten the bleeder and pump it up to pressure.

Good luck!

[LanduytG]

Mine pumps let crap compared to others that I have changed filters on. When I take it in for the reflash that is one thing I want replaced.

Greg

[Jim Brzozowski]

You know of all the information I've seen on the forum about bleeding the fuel system, I haven't seen anyone mention what I think is the absolute fool proof way to get all of the air out. I change the oem and a secondary post oem Racor and all I do is Open the fuel cap on the tank, take a 3/16" drill bit and open the scharader valve on the front of the engine,(black cap about 1"in diameter)on the right side of the engine)and push the blunt end of the drill bit aginst the valve, just like you do a tire valve if you want to let air out, and then I start pumping, do a few pumps and push the valve. It's also a good idea to use shop towel or something to catch the fuel that will start to spit out of the valve as you pump. When it is flowing fuel and not spitting out air, take the drill bit out and wipe up any fuel left there and put the cap back on. You're through. You never had to open any bleeder valve and you have pumped filtered fuel through the filter all the way through the system. There is no air and I have never once had to bleed twice. Ever. Try it you might like it. It works.

[CMC1]

Yes I'm opening the bleeded. SOTX- thanks I will locate that and give it a try on the next one.

[DmaxMaverick]

A word of caution here.

That "schrader valve" is a diagnostic port. Using ANYTHING to open it, other than the correct coupler, could cause very costly damage. I'm not sure how SoTxPollock is opening it with a "drill bit" (I can draw a mental picture), but the hardened steel the bit is made of will certainly win out against the brass fitting. If the valve becomes damaged, it will not only leak under pressure, but may allow air (among other things, post filter) to enter when the engine is off. I don't hold much stock in a plastic cap. If you were to damage the fitting, and later have issues with the fuel pump, or injectors, the dealership would have a good leg to stand on when he denies your warranty claim.

Bleeding air from the highest/latest point of a system is ideal, no doubt. If you use the diagnosic fitting for bleeding, I suggest you obtain the correct coupler to access it. JK sells a pressure gage kit that uses the port, with the correct coupler. He may be able to provide the coupler, then you could attach a hose to it and bleed under the most ideal circumstances.

[jbplock]

Originally posted by DmaxMaverick:
A word of caution here…

That "schrader valve" is a diagnostic port. Using ANYTHING to open it, other than the correct coupler, could cause very costly damage... I suggest you obtain the correct coupler to access itDM makes a good point regarding proper use of the Schrader valve. I added a valve to the Kent Moore gauge that allows easy bleeding of the fuel system with a lift pump from the Schrader port. I’ve found that when bleeding from this port after a filter change, the engine starts right up without any long cranking and/or stalls. This is a convenient method but one should still able to bleed at the filter(s) and easily get the engine started. If not there is another problem.

http://thumb2.webshots.com/s/thumb4/6/56/82/95465682wVUGYc_th.jpg
Modified Kent-Moore Vac-Pressue-Bleeder Gauge (http://community.webshots.com/album/73314886FLnSco)

(John's gauge is better but it wasn't available when I bought this one)

smile.gif

[Jim Brzozowski]

DM,yes, I agree the schrader valve is a very important part of the fuel system, since it has to hold all of that pressure, all I am doing with the end of the drill bit that fits into a drill motor is use that end of it to push against the stem of the valve with my hand on the sharp point of the bit, I would cut my hand on the bit before it would do any harm to the valve stem, you can probably picture that. I guess you could use the eraser end of a pencil, but I thought that may not be a good idea since the possibility of some of the eraser material droping off and getting stuck in the port. Cleanleness if paramount here.

jbplock, I like your gage idea, as you well know when you bleed from the high point there can be no trapped air in the system since the density of the fuel is so much more than the air it will force the air to the top. Yes I'd like to have the correct hook-up to that port that way the extra tubing you could add would make for a very clean operation and no spilled fuel on any part of the engine or accessory belt.

[02MAX87GN]

CMC1

To answer your question. Yes my priming pump had a diaphram or something fail in it and it would not pump any fuel into the filter. I spoke with the dealer tech and it was not the first he had replaced. My truck had 53k miles on it and they replaced it under warranty but I had to pay $100 deductable since it was over 36k. I first thought I could fix it for $100 but when I got the bill the pump and filter assembly listed for around $670.

[LanduytG]

Bill
Whats the Kent Moore part number?

Greg

[mdrag]

Greg,

GM Vacuum gauge part# J44638 (http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=3;t=007014)

HERE'S (http://forum.thedieselpage.com/ubb/ultimatebb.php?ubb=get_topic;f=3;t=007424#000000) a topic discussing vacuum gauges.

[CMC1]

Thanks, O2. I'll ask my dealer. They treat me pretty good.