Veg oil injecytion pump leak - ideas?

I have been running 50/50 veg oil diesel for about 3 weeks now, my injection pump appears to be leaking. Tis an N/A diesel, with about 100,000 miles. Any ideas? Do I need to look for a new pump? Hope not... Odd thing is the liquid coming out of it doesn't smell of much at all, doesn' smell strongly of diesel either. Ideas..?

Mine did that a few weeks ago. Looked like it was from the pipes from the pump to the injectors, so I cleaned them up and the banjo bolts that connect them into the pump. I then undid the banjo bolt and did them up again.... hasn't leaked since. (400 miles ago)
All I can assume is that the veg oil in mine has cleaned out all the gum and rubbish in the fuel system such that it caused the fuel to leak out past the washers.

Wherever it's coming from I doubt very much if it's veg oil that's caused it.

This pump is probably not happy with that much veg oil to be honest.

The CAV is not the most sturdy amongst the injection pumps used in LR engines, with the cold weather at that percentage I would think the oil was a little too heavy. If it is a pump leak and not a bad union, send it to a lucas shop and have them overhaul it for you. They still exist, there is one in Glasgow.

If you're not pre heating the fuel a 50 / 50 mix is a bit thick especially when its been so cold. I'd stick to 30 (Veg) / 70 (diesel) in the depths of winter. CharlseY recommends a dash of kerosene as a good thinner in winter, there's plenty of threads dotted with stuff like this. You'll have to wade through pages to get to them though.

Mine gets pre heated and to be honest, in winter it takes about twice as long to reach the required temperature to be thin enough to push through the injector pump. At the moment I'm averaging 2 ltrs of diesel to 1 ltr of veg. In Summer its the other way round.

Good luck

it doesn't obviously appear to be a bad union, although it could be the fuel in pipe. It could also be from the seam that appears to run around the body of the pump. Do these pumps have a coolant feed from t'engine, to heat the fuel? Cos as i said, was is leaking doesn't appear to smell of anything much at all... And i shall thin out the veg oil and see if the leak improves.

Nope, the coolant is the diesel fuel, the whole casing is full of diesel, so it really has to be diesel.

A small quantity of diesel on your finger is not going to smell that strong, especially if its been diluted with the SVO.

The favourite place for these pumps to start leaking fuel from is around the throttle lever spindle.

It is sealed by a tiny O-ring, which can easily be replaced, after the top cover is lifted off the pump.

CharlesY

That actually is where i initially thought it looked like it was coming from - where can i get a new o ring from, and how easy is it to replace? I am fairly mechanically minded, but have never eern been inside a doosel pump before - can i do that job in situe, or do i have to remove the pump? The other problem is I am in university halls of residence, so I have to be careful about what I spill over their car park :-D
Do you get Veg-Oil-Proof seals/o-rings?
All help is greatly apprechiated!

Get yourself a selection box of good quality O-rings, and find one that fits.

Nitrile rubber oring will do your diesel and SVO.

Nitrile (Buna-N, NBR)
Nitrile rubber is the general term for acrylonitrile butadiene terpolymer. The acrylonitrile content of nitrile sealing compounds varies considerably (18% to 50%) and influences the physical properties of the finished material. The higher the acrylonitrile content, the better the resistance to oil and fuel. At the same time, elasticity and resistance to compression set is adversely affected. In view of these opposing realities, a compromise is often drawn, and a medium acrylonitrile content selected. Nitrile has good mechanical properties when compared with other elastomers and high wear resistance. Nitrile is not resistant to weathering and ozone.
Heat resistance
Up to 212°F (100°C) with shorter life at 250°F (121°C).
Cold flexibility
Depending on individual compound, between –30°F and –70°F (–34°C and –57°C).
Chemical resistance
Aliphatic hydrocarbons (propane, butane, petroleum oil, mineral oil and grease, diesel fuel, fuel oils) vegetable and mineral oils and greases
HFA, HFB and HFC fluids
Dilute acids, alkali and salt solutions at low temperatures
Water (special compounds up to 212°F (100°C)).

Time for some silicone hoses if you are not already running them. This mix will dry parts out and cause issues that you have come up against.

Again, where do i find these, and what should i expect to pay? Thanks again!

Does anyone also have any information/pictures, etc about how to dismantle this pump and what I will see inside? Can it be done without removing the pump first? The leak has got rapidly worse, and I still can't work out where it is coming from. Do i need a new gasket for around the edge if i take the lid off? Thanks again!

boydy1989 said:

Does anyone also have any information/pictures, etc about how to dismantle this pump and what I will see inside? Can it be done without removing the pump first? The leak has got rapidly worse, and I still can't work out where it is coming from. Do i need a new gasket for around the edge if i take the lid off? Thanks again!

Click to expand...

Very difficult to access diagrams - they want to keep it secret so we have to use their VERY EXPENSIVE services.

The lid comes up quite easily, and then o-ring is simple to replace, but of course the job is best done "on the bench".

You should NOT need a new gasket around the lid. Might be difficult to source on anyway.

Fuel injection pumps are NOT magic. They are simple mechanical devices, albeit with lots of little pieces involved.

Get an old one and try taking the lid off it.

CharlesY

discomania said:

If it is a pump leak and not a bad union, send it to a lucas shop and have them overhaul it for you. They still exist, there is one in Glasgow.

Click to expand...

theres one in tunbridge wells as well!

Thanks again, I would love to be able to do it on the bench, but unfortunately my uni halls of residence are lacking in these facilities. :-( Why could this not have happened while i was home in surrey... I could pop down to tunbridge wells then too! Do you happen to know what size o-ring I will need?

Robin