How can I drain my 850 AWD fuel tank (with dead fuel pump)

OliG · Post by **OliG** » 08 Nov 2011, 16:55

Hello,
I just tried to replace my fuel pump that keeps blowing fuses. I did it following advices posted previously here:
https://www.matthewsvolvosite.com/forums ... =1&t=20367

The swap went quite well, got the whole thing reassembled quickly with the new fuel pump, tried to fire up the car, I can hear the pump running but... I got no fuel at all at the fuel rail. I guess the pump disconnected from the pipe that leads to the output line. The pump I bought was longer than the original one so I removed a gasket at the bottom of the fuel pump assembly. I think and hope this was my mistake.

So now, I want to disassemble again, but the problem is that I did add gas to the tank before turning the car over. An other mistake I know... Now, if I try to unscrew the fuel pump collar, gas leaks out badly. I would like to know if it is possible to drain the fuel tank without the pump and without dropping the tank? I did try to syphon from the gas input but I guess there is a safety device (?) because my hose didnt reached the fuel...

Any help is appreciated, I'm running out of solutions right now

Thanks !

Oli

FCPEURO · Post by **FCPEURO** » 08 Nov 2011, 17:21

I would use a hand pump. Just remove the bad fuel pump and put the hose from the hand pump in the tank and pump away.

OliG · Post by **OliG** » 08 Nov 2011, 18:10

Hello,

Thank you for the input, but unfortunately my 850 is the AWD version, who has the fuel pump assembly installed on the side of the fuel tank... If I unscrew the pump retaining collar, gas will spill everywhere until the tank is near empty.

Is there a way to go an other route ?

Thanks again !

Post by **JimBee** » 08 Nov 2011, 18:47

You'll probably come up with a better solution than this, but just in case that doesn't happen, here's what I might do.

Jack up the car on the side of the fuel pump as high as you can. Maybe use blocks for support and go even higher. Stop when it feels unsafe.

Get a polyvinyl concrete mixing tub from a big box hardware store. Set it under the tank where gas will spill. Be ready to move it around in a hurry when you loosen the pump.

Let it drain until you can remove the pump without getting a shower.

You'll probably lose 5 gallons or more. But what I might also do is when I'm at the hardware store, go to their paint section and pick up a couple of paint strainers (the real fine mesh ones).

You'll need a large clean container and an accomplice.

You'll probably know how to do the rest.

Post by **renns** » 08 Nov 2011, 19:44

In my AWD fuel pump adventure I was fortunate in that the pump died with the fuel level about 1/3 tank, so I didn't have to deal with that issue. How about popping a rubber hose onto the return line tube at the pump assembly, and using that to siphon the fuel? That should work I would think. Also, parking the car on an incline, nose-high will shift the fuel back away from the pump opening, so that might be worth trying as well, once you are down to 1/3 tank or so.

I ended up having a heck of a time fighting leaks at the pump flange after reassembly. To properly torque the big plastic nut, I fabricated a tool that engages two opposing fins, and allows tightning via wrench. Also, the VADIS instructions advise to lubricate the rubber seal with vaseline prior to assembly. Those two steps were what was needed to stop the leak in my case.

Post by **jimmy57** » 08 Nov 2011, 21:37

The return line goes to the other side of tank and is used as the driving fuel for the ejector pump that delivers left side fuel to the cup on right side. It won't work for siphoning. Your installed pump may push it out if you disconnect the snap on outboard line as that is the outlet line, slide a hose on, and then jumper the rear terminal to battery to get pump to run.
I tried a replacement pump and something about the fit made it not pump right and froth the fuel up to rail. I had to go get a new assembly from dealer. Dealer was more than $200 cheaper than aftermarket whole assembly. Volvo dropped the price on it some time in the last year.

OliG · Post by **OliG** » 09 Nov 2011, 08:00

Hi,

Thanks for all inputs this is appreciated. I also tought about draining from the return hose, but It would only work partially as this hose is plugged at the highest point from ground on the fuel pump module. If I have no other options, I will remove the most fuel I can by the return hose, then park the car on an incline (luckily my driveway is both flat and incline), and then try to recover the remaining fuel with a pan when I unscrew the plastic collar.

But, before I do that, I would like to be sure : There is no way I can syphon from the filler neck? I did tried using a hose of around 5/8" diameter, could a smaller hose make it to the tank?

Thanks !

Oli

Post by **renns** » 09 Nov 2011, 08:35

jimmy57 wrote:The return line goes to the other side of tank and is used as the driving fuel for the ejector pump that delivers left side fuel to the cup on right side. It won't work for siphoning.

Sorry, misunderstanding here. My suggestion was to connect a rubber hose to the return line fitting on the pump assembly. If the return line doesn't sit low enough in the tank, siphoning through the pressure line on the pump could work as well, if in fact it's connected properly. If it's disconnected as you suspect, then that option's out.

Post by **jimmy57** » 09 Nov 2011, 10:25

The problem is still that the return line goes just inside the top of the fuel pump vessel which is about mid-point of the hole in tank where the unit inserts

Post by **cn90** » 10 Nov 2011, 09:05

OliG,

I just re-read your post. You have a new fuel pump and there is no gas at the fuel rail.
Then jump the fuel relay, if the pump now works, then the relay is bad.

Info on jumping relay, basically jump terminals 15 and 87:

http://volvospeed.com/vs_forum/topic/92 ... -bypassed/