Replacing the Low Pressure Pump in the fuel Tank

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Replacing the Low Pressure Pump in the fuel Tank

Post by PillowSmuggler » Sun Sep 09, 2018 8:54 pm

Following on from my post here :
viewtopic.php?f=3&t=5562&p=193008#p193008

Here's what was happening at the engine end of the LP fuel rail:



Got a new aftermarket pump assembly (not just the pump, as research shows that it's best to have the new thermostat and pipework also) as well as a new tank gasket since getting back, so tackled the job this weekend.

I was using the Haynes guide for the instructions, which covered all the basics though as expected was sadly lacking in a couple of important details which I'll try and list here.

One detail was the location of the "grey" push-fit connector at the rear of the tank. There's a yellow clip connector and a grey connector but the grey one is all but invisible. I found it behind the top of the air shock turret housing, out of sight from the wheel housing and difficult to get the hands in to put enough pressure on the push buttons (it was full of mud, go figure?). Removing the spare wheel brought it into view and allowed a mini set of water pump pliers to press the tabs.

All six bolts holding the tank in were corroded in place, so lots of shock and unlock fluid used to get them moving. Eventually dropped the tank using a jack and was able to reach in to the front fuel connectors. And that's where everything was different to the guide again, as instead of two push-fit connectors to undo, there were four, the extra two were connecting to the 2007MY onwards fuel filter housing.

I also disconnected and removed the FBH fuel pump as it looked like this would foul the tank during removal.

After another 20 minutes jetting with a high pressure air line the rock like mud was blown out of the electrical connector tabs on the top of the tank and it was eventually able to be removed.

It's not in any guide but the front left top of the tank has a black nylon shroud that bolts down into the steel undertray; this has to be removed to separate the tank itself from the bash plate.

After all that I (well my youngest actually) swept up and binned about 6Kg of mud and gravel.

The plate appears to have a slight bow to it, but I'm not sure if this is because it's supposed to be there or if I've landed it hard on a rut and bowed it.
Nah, can't have been that, right?

With the tank out there was thankfully very little fuel spillage, and I got it out to the side of the car and using a wire brush and high pressure airline cleaned the connectors on the access plate and removed it.

Oh my. So much rust/mud inside. All the white plastic was coated with a film of rust and there was some evidence corrosion on all the electrical connector spades. The worst rust was on the pump motor body itself. The pump filter screen was as nasty as any you've seen in any other posts across the interweb; covered totally in black slime and the bypass screen was also almost totally covered. I suspect this is the reason for the failure; the main filter is totally blocked, so it was pulling (less well filtered) fuel through the bypass screen, and that itself was blocked and so restricting flow.

I was surprised by the amount of metal shavings in the tanks filter. It looks like the same metal as the petrol station fuel pump nozzles are made of, some sort of zinc alloy I think as It's non magnetic.

There's a green band made out of a sinusoid shaped plastic, and this provides an elastic clamp to holding the pump module in place. There's a semicircular plastic baffle that the pump module sits against, then a further 1/4 circle that is hinged to allow the pump module to be removed, and then the green band pulls it all together. It's very solid and I cannot see it ever shifting in normal use unless you really clout the tank.

The replacement part looked identical to the original one, except the pipes headed off at a weird angle as the cable tie was obviously in the wrong place. A quick snip and a new cable tie made both parts identically shaped.

Haynes said that refitting is the reverse of removal. I really hate those words, as it's almost always a lie. It was here too. My big plates of ham simply couldn't replace that green strap and leave enough room for a torch to see where I was aiming as well as a finger to hold the 1/4 circle hinged portion closed. Took a good 20 minutes of try try try again to finally get it in place, and the same went for the thermostat housing.

Refitting the remaining connectors was simple enough compared to the effort to remove them - simple push to fit. There was one pipe that remained in the tank that just seemed to be flapping around loose. The only place I could find for this was pushed onto the stub on the access plate that connects to the fuel return from the High Pressure Pump. This was not there when I took it off, so I hope that it was the correct place for it.

That's as far as I've got this weekend; next I'll be refitting the tank and then having a look at the gearbox leak. I have a lot of bolts to wire brush and copperslip first so probably another couple of hours work in the tank before heading into the gearbox to see where the leak was from.

And yes, I did check the new pump worked before refitting it ;)
IMG_20180909_153358.jpg
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Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by anglefire » Mon Sep 10, 2018 7:46 am

That sounds a right barrel of laughs Dom, hopefully when its all back together it solves the problem - which by the sounds of it could have just been blocked filters? Not that I wouldn't change the pump anyway!


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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by PillowSmuggler » Mon Sep 10, 2018 12:32 pm

Yeah, it's been a right chuckle Mark :lol:

I'm not saying that it's only the pump, but it was pretty dire and desperately needed replacement.
I've just been in and added some random piccies, and you can see the film of rust on all the plastic parts, as well as the rust on the pump body itself.
In the clear pic of the electrical connectors, it looks like cream, yellow, brown, but actually that first one is a white plug, and a quick spray of brake cleaner cleaned all the :censored: off back to white without scrubbing. Every surface of the inside of the tank has that film on it. It's weird, as it doesn't seem to be in the diesel itself.
I did get a new pump motor a long while back from Gordon as a spare, but I could not find it or I'd have been tempted to just replace that. Having seen all the rust on the thermostat housing and its earthing clip I'm glad I went the whole hog instead.
Although I took the job slow to prevent cockups, I think now that I know what to expect I'd probably do everything in half the time if there ever is a next time. Just things like "exactly how hard do you have to pull this green strap before it breaks" takes a long while as you gradually increase the force you exert each time you fail to get it to lock, but next time I'll know you just have to Schwarzenegger it LOL.

I am still undecided as to whether to slosh a litre or two of brake cleaner into the tank and swill it round to remove most of this :censored: and then let it dry out before refitting. Have to say I'm very tempted as I'd feel better with all that carp out, but I need to look up what burning isopropyl alcohol in a diesel engine does that's bad. Any ideas?
Also, if that carp's been circulating around the main fuel filter and HPFP then I'm thinking a new fuel filter is also in order. I did check it for water on the fuel filter drain but only oil came out, so I can only assume the rust was a result of condensation in the tank when it was mostly empty.

Next job will be the gearbox and I'm looking forwards to that even less. I did at least prove that gears 1,2,3 and R worked just fine without any weird snatchings or funny noises so there's hope yet!


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by Bodsy » Mon Sep 10, 2018 9:56 pm

Clive did his last month, and I did mine before going to Italy a few weeks ago.

Thought I’d posted it but on here, but here it is anyway.
[Been a busy weekend!

Changed my in tank fuel pump this weekend. Thought I’d take the opportunity to clean down and paint the fuel tank cover whilst I was at it.

Getting a fuel related fault code which as I’ve got new HP fuel pump and everything else on the engine new (including genuine fuel filter) can only leave the low pressure fuel pump. As it’s done 255,000 miles, not a problem to change it!

Drove the car up my ramps to give a little more clearance.

Then using axle stands and trolley jack, lowered the tank whilst unclipping the various pipes.

Had around 1/4 tank of fuel, but I already knew that the tank had an anti leak device (thanks Clive Symons) so instead of draining it, I just dropped and disconnected the tank and then used a small fuel pump to drain it once the top was off.

There was a fair amount of dirt that had built up over the last 11 years!

Tank cover had rust but not too bad.

Wire brush on a grinder, then some 40grit sanding disks had it cleaned up in no time.

Also cleaned the underside of the chassis where the fuel tank was.
Very little rust behind it tbh but cleaned and coated it with Corroless EPF two pack (that I used in the rest of the chassis when I split the body off earlier in the year.

All back together, bled back through the air and starts no problem.
Didn’t have chance to test drive it to see if it cures the fault code I get but will do that Tuesday evening.

Need a couple of the captives nuts replacing so will get those and fit them Tuesday.
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]



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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by PillowSmuggler » Wed Sep 19, 2018 8:32 am

Cheers Ian, made a good checklist I'd not missed anything :lol:

Tank is back in the car, and refilled - pressure looks good although a max of 5.5psi not the 7.5 I expected. Under full RPM the pressure now stays positive - just, but that's enough I guess? The engine is also running much much quieter.

Before putting everything back, I took a stand on the fuel elbow by adding some protection to it using old jubilee clip parts:
IMG_20180915_131904.jpg
And finally when i re-used my old diesel (yeah, I'm tight, I know) I put it back through a filter/separator to remove any water/carp:
00002IMG_00002_BURST20180915160721_COVER.jpg
IMG_20180915_131904.jpg
I left approx 1/2" at the bottom of the containers just to be sure.

I took a look at the gearbox next. The leak is coming from the electrical plug, so I have what they strangely refer to as a new vacuum control sleeve on order.

As replacing this requires the sump off the gearbox, and as I have no nice 2 post lift to work under to simplify lifting the gearbox to get the filter out and back in, I've also got a BMW style metal sump and filter on the list, and yet more oil. It badly needs the oil though, so no complaints. I have test driven it (gently so far) and can confirm that I have all the gears, lockup works smoothly without snatch or rpm surge, and shifts up and down are smooth as silk. I'm faintly optimistic that although I will surely have aged the 'box considerably by overheating, the signs so far look like I haven't killed it.

Looks like next weekend will be gearbox weekend, and if the weather stays on track I'll be lying under the car with water running down my neck; loverly :(
Attachments
IMG_20180915_160726.jpg


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by anglefire » Wed Sep 19, 2018 12:42 pm

You've presumably seen the pictures I took when I had my sump replaced Dom?

https://disco3club.colston-online.co.uk ... index.html


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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by PillowSmuggler » Thu Sep 20, 2018 5:17 pm

Indeed I did Mark, but now I've seen them again I'm replacing the items in pics 20 and 24 as well as the sump and filter. I won't have all that loverly headroom though - chestroom only for me :(


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by PillowSmuggler » Thu Sep 20, 2018 5:21 pm

That's reminded me of a question I had - that sump is designed to hold less fluid (as shown by the fact it has it's own fill point) but why can you not still use the level based on the side fill plug? The 'box would allow that extra depth of oil as long as the old fill plug level is not exceeded, so why the need for less oil? In a landrover I'd have thought the more spare the better...


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by anglefire » Thu Sep 20, 2018 6:01 pm

I think it's less due to the depth of the sump rather than anything else. It's my view thathe side hole is fine - and probably the same in reality.


Mark

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Re: Replacing the Low Pressure Pump in the fuel Tank

Post by PillowSmuggler » Thu Sep 20, 2018 10:28 pm

Yes, I suppose the new sump plate filler projects up a fair way; I guess it could be the same. I wonder why the drain plug is not at the lowest point on the new sump though.

Probably not important. Thankyou!


Regards, Dom.
2007 HSE Auto TDV6
Snorkel, Cyclonic air filter, GNVP Rock Sliders
78Ah Aux, Split charge, FBH Timer/Remote, Mantec sump plate
LED: Strobes, interior, camping, brake, running, sides
New Oil Pump, using 2SO at 1:400.

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