Petrol tank 740

[panda529e699]

Hi

I am looking in to removing the petrol tank to do some welding.
Would be keen to hear if anyone has done this before, and advice on it please.

Thought about replacing the straps as well, fortunately still available new.

Thanks
Andrew

[Laird Scooby]

Originally Posted by panda529e699

Hi

I am looking in to removing the petrol tank to do some welding.
Would be keen to hear if anyone has done this before, and advice on it please.

Thought about replacing the straps as well, fortunately still available new.

Thanks
Andrew

First bit of advice Andrew - run!

Actually it's not too bad a job really. First, make up some WMP (50/50 acetone/Carlube ATF-U) and give it a good shake, keeping it in a sealed container when not in use. Give it a good shake before each use and reseal after. Dribble some on the threads of the long studs/bolts that connect the tank straps, preferably after giving them a wire brushing to remove and loose dirt/debris/rust etc. Reapply a few days later.

When you coe to remove the tank, inside the car, remove the three nuts holding the load deck cover down. These are revealed when the backs of the rear seats are tipped forwards and the spring-loaded flaps lifted. Once the thre nuts are off, lift the load deck covering and pull it forward to release the two hooks from the loops they lock into.

Find the fuel pump/sender access plate just above the axle in the floor and remove the 4 10mm headed screws, lift off the access plate.

Disconnect the flow (12mm bore) and return (8mm bore) fuel hoses from the sender/pump plate, the fill pipe and the breather hose.
Now, using a piece of wooden batten as a drift, place the end of the drift on one of the "ears" on the lock ring to the left of centre and tap it down with a lump hammer on the other end of the wooden drift to loosen it. Once loose, spin it off by hand and then remvoe the pump/sender unit and sealing ring - best to renew the sealing ring, about £11 from Volvo.

Working underneath now, loosen the nuts on the studs/bolts that hold the straps together until the stratps can be separated from each other - you'll see what i mean when you do it.
Slide the tank down and backwards to remove it - it's surprisingly light!

Should have said, make sure there's as little petrol as possible in the tank before you start!
While the tank is out, take the opportunity to renew the fuel flow and return hoses from the tank to the hard nylon lines (green ones) as they can't be accessed without removing the tank.

Refitting, you "Haynes it" but be careful to jiggle the tank a bit as you do the strap bolts up to help it settle int the right place, use a new seal as already mentioned for the sender/pump unit and tighten the locking ring the same way as you loosened it but by putting the wooden drift to the right of centre as viewed from above. After about 6-8 weeks, check tighten the lock ring, the seals seem to settle and can leak - as my MoT tester pointed out when he got a 98 octane shampoo over his bald patch!

Useful tip, you can put the car on ramps to check tighten the lock ring, crawl under and whichever way you look at it, the outboard side of the lock ring needs to go up to tighten so drift on the outboard side and a couple or three good thwacks with the lump hammer should do it. If it has leaked, there will be a slight damp or dirty patch on the back of the tank underneath the lock ring - wipe this clean and keep an eye on it to make sure you've got it leak free.

Apart from "Volvo Gynacology 101 - Removing and Refitting the fuel pump/sender unit", it's a straight forward job, just a bit time consuming.

[panda529e699]

Originally Posted by Laird Scooby

First bit of advice Andrew - run!

Actually it's not too bad a job really. First, make up some WMP (50/50 acetone/Carlube ATF-U) and give it a good shake, keeping it in a sealed container when not in use. Give it a good shake before each use and reseal after. Dribble some on the threads of the long studs/bolts that connect the tank straps, preferably after giving them a wire brushing to remove and loose dirt/debris/rust etc. Reapply a few days later.

When you coe to remove the tank, inside the car, remove the three nuts holding the load deck cover down. These are revealed when the backs of the rear seats are tipped forwards and the spring-loaded flaps lifted. Once the thre nuts are off, lift the load deck covering and pull it forward to release the two hooks from the loops they lock into.

Find the fuel pump/sender access plate just above the axle in the floor and remove the 4 10mm headed screws, lift off the access plate.

Disconnect the flow (12mm bore) and return (8mm bore) fuel hoses from the sender/pump plate, the fill pipe and the breather hose.
Now, using a piece of wooden batten as a drift, place the end of the drift on one of the "ears" on the lock ring to the left of centre and tap it down with a lump hammer on the other end of the wooden drift to loosen it. Once loose, spin it off by hand and then remvoe the pump/sender unit and sealing ring - best to renew the sealing ring, about £11 from Volvo.

Working underneath now, loosen the nuts on the studs/bolts that hold the straps together until the stratps can be separated from each other - you'll see what i mean when you do it.
Slide the tank down and backwards to remove it - it's surprisingly light!

Should have said, make sure there's as little petrol as possible in the tank before you start!
While the tank is out, take the opportunity to renew the fuel flow and return hoses from the tank to the hard nylon lines (green ones) as they can't be accessed without removing the tank.

Refitting, you "Haynes it" but be careful to jiggle the tank a bit as you do the strap bolts up to help it settle int the right place, use a new seal as already mentioned for the sender/pump unit and tighten the locking ring the same way as you loosened it but by putting the wooden drift to the right of centre as viewed from above. After about 6-8 weeks, check tighten the lock ring, the seals seem to settle and can leak - as my MoT tester pointed out when he got a 98 octane shampoo over his bald patch!

Useful tip, you can put the car on ramps to check tighten the lock ring, crawl under and whichever way you look at it, the outboard side of the lock ring needs to go up to tighten so drift on the outboard side and a couple or three good thwacks with the lump hammer should do it. If it has leaked, there will be a slight damp or dirty patch on the back of the tank underneath the lock ring - wipe this clean and keep an eye on it to make sure you've got it leak free.

Apart from "Volvo Gynacology 101 - Removing and Refitting the fuel pump/sender unit", it's a straight forward job, just a bit time consuming.

Many Thanks for the advice, did it last week went very well.

Have ordered new seal and some new stainless jubilee clips, plus the fuel hoses you mentioned, they are arriving tomorrow so that's the next task. Re-fitting.

Getting the stuff from Skandix, ordered on Monday, arriving Wednesday, thought that was super fast.

Andrew

[Laird Scooby]

Originally Posted by panda529e699

Many Thanks for the advice, did it last week went very well.

Have ordered new seal and some new stainless jubilee clips, plus the fuel hoses you mentioned, they are arriving tomorrow so that's the next task. Re-fitting.

Getting the stuff from Skandix, ordered on Monday, arriving Wednesday, thought that was super fast.

Andrew

Good to hear it all went well Andrew, it's one of those jobs that seem daunting until you do it and then you wonder why you were worried.

I used a smear of silicone grease on the threads of the locking ring to help get it tight as well and a tiny smear on the outer edge of the sender/pump unit where it fits inside the seal just to help it slip into the seal as it should.

Looking forward to the finished report!