THE PORTAL HUB - Pinzgauers, Haflingers, Volvo 303s and more!

I just rebuilt the fuel pump. It went well and no real issues. However, now it seems the pump is not pumping at all.

I just spent the last 1.5hrs reading up on fuel pump posts and didn't find a ton of info, most are just about fuel delivery issues and the pump being the problem.

So I did the normal stuff; rebuilt the pump, replaced the tiny filter in it, changed out the shaft the rocker rides on, packed with grease, ect ect. Couldn't find any torque specs on any of the pump stuff so just tightened it down to about what it felt like when I removed it all. Went through the normal procedure to fire it up. Crank 10-20 seconds, let it sit for 30 seconds, repeat. After a lot of this no fuel to carbs, filter dry, ect. I pull lines at the pump, inlet side totally dry. I prime the filter and the pump, still nothing. Crank over with pump primed and no fuel lines to see if any of the fuel that I put in the pump for priming is coming out. No fuel when I crank. I tried a cup of fuel to the inlet side and the pump is simply not sucking at all.

Could I have done something wrong in the fuel pump rebuild? If so what might I have done?

Is it just a real SOB to get primed and pumping after a rebuild? If so, use a cup on inlet side and elevate it above the pump? As mentioned I tried the cup of fuel but it wasn't elevated above the pump much. Would this make a big difference?

I know the pump isn't pumping because I can hold the full filter upright with the fuel facing down towards the pump, crank engine and the fuel in the filter goes nowhere.

One thing to note, the diaphragm in the bottom of the pump didn't want to line up real good with the holes for the two halves. I was able to work it a little bit at a time and get it together and don't think I tore anything. Anyone seen this with a SAV kit? Perhaps I damaged the diaphragm though due to it not fitting real well? A hole or two in the diaphragm really didn't want to line up so I used a very small screw driver to open up the holes (stretch it) as I inserted the screws. Seemed to go together alright but I can't think of anything else I did that would have been an issue in the pump rebuild.

Cheers

I figured it out on my own, the truck runs great!

Cheers

What was it?

Were in and out reversed? Seen that done.

krick3tt wrote:Were in and out reversed? Seen that done.

That is my guess too

Nah that wasn't it. I didn't have the lever on the plunger correctly below the diaphragm. IE, the fork end was not on the plunger rather under it. This was 100% my bad and a dumb mistake. I knew the fuel pump was so simple I didn't pay much attention when I tore it down. I also didn't pay close enough attention when I reassembled it. I looked for answers here on the forum before I tore it out a 2nd time but found none. The fuel pump rebuild thread is good but IMHO could use a bit more info and pictures to prevent a noob mistake like I made. None of the books show or explain enough to reference those too when you make a mistake like I did. Tearing it down a 2nd time, playing with it and in 15 minutes it was clear what I had done wrong. I am just glad I didn't damage something since it could have gotten expensive fast! Also the new diaphragm has slight tear at the outside edge of the hole that wouldn't line up. Although I don't think that presented a problem. I put the old diaphragm back in and will just put the new one in my spare parts kit.

Cheers