discovery

Repairing Discovery 300TDI Auto Cruise Control

Just a quick guide here on repairing the most common problem with Discovery 300TDI Auto cruise control – the vacuum hose.  These rubber hoses seem to quite easily perforate or crack over time and it’s very easy to fix.  Firstly, if the cracks are small and near the joins just cut the hose and reconnect.  This only works if you have enough hose.  In my case the hose has already been cut too short and is actually just dangling in the engine bay.  So a quick trawl over to ebay found new silicon hose cheap enough.

I’ve purchased some silicon hose – 5m of 5mm internal diameter and 10mm outer.  This gives 2.5mm of wall which should be enough.   5m is overkill too, but it leaves about 1m for the toolbox.

Discovery 300TDI Auto Cruise Control Vacuum Hose - simple tools required

Tools required are very basic – a good knife, some pliers and some nice hot water.

First off, I’m starting at the auto speed controller unit thingy (I’m guessing there is a real name for this unit).  The hose here for me has already cut by a previous owner, but clearly this was too short and didn’t reach the t-piece.  So that’s a timely reminder to measure twice and cut once 🙂

So, taking the old hose off (very easily in my case), I use this to measure the length of new hose required.  Remembering in my case that the hose was too short, so I’ve added to the length (best to measure long and cut back later if your not sure).  Using the hot water to warm the silicon doesn’t seem to make any difference, but as a homage to the old rubber hoses and to make me feel better I’ve done it anyway.

Discovery 300TDI Auto Cruise Control Vacuum Hose - hot waterWith one end connected to the Auto unit, I warm the other end going to the t-peice.  Once connected up it’s time to look at the longer pipe.  Remove from the T around the bulkhead and into the aux battery/jack area.  Here the pipe dives under what would be the battery tray and into the pump.  The pump is not easy to see and whilst it can be removed, I’m not looking to waste time.

Drilling off the jack mounting plate to gain access to vacuum pump

 

So with that thought, I’ve drilled the rivets holding the pump base into place and removed.  This gives just enough access from the top to do the job and I can replace later if needed.  Removal of the old hose shows that it was completely perished and not even connected to the pump.

Now use this pipe to measure a new length – as always a bit longer is better and remember it can be cut back later.  I’m starting by connecting at the pump end.  On the right hand side of the pump are two projections – your aiming for the back one, slightly shorter.  Push it on as far as you can and give it a tug – it should be a secure fit.

Discovery 300TDI Auto Cruise Control Vacuum Hose - to the pump

 

The picture above shows the red silicon hose that I’m using and just visible through the left hold is part of the pump.  Now route the hose back around the bulkhead using the clips where available and trim if required at the t-piece.

Discovery 300TDI Auto Cruise Control Vacuum Hose - T piece connected

 

Connect to the t-piece and you should have replaced most of the hose.  There is one more that goes through the bulkhead into the drivers footwell, but this one is in good condition for me and I’m stopping at this point.    So final picture from me shows a little more of the engine bay and the new red silicone hose.

Discovery 300TDI Auto Cruise Control Vacuum Hose - complete

 

So did it fix the problem… oh yea 🙂  fully working Cruise Control now on my 300TDI Auto!  Simple fix and only 10 mins of my day used.

Just found a nice guide to the rest of the system – it can be found on Landyzone here.

 

Landrover Discovery 300TDI running on 100% SVO (straight veggie oil)

I’ve been running the landy on 50/50 veggie to diesel with no problem, but now the colder mornings are creaping in she is starting to get a little grumpy. Once warmed up the landy performs as usual without any clear difference (although people do feel compelled to tell me that it smells like a chip shop). I’ve added a heater element around the fuel filter which just cut’s off by thermistor when it reaches 90 degrees and kicks back in at 70; but this is just not enough for the colder mornings and days.

So, I’ve invested in something to make the veggie oil a little bit warmer (and therefore runnier) – it’s from Vow2. I’ve bought the VOW2DW+ unit which heats the oil from a couple of glow plugs and plumbs into the heating system of the engine. It pre-heats fuel on the way to the filter and warms it nicely on route to the pump and injectors.

Picture of the kit purchased.

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First off was the put the unit roughly in place and measure out the fuel pipes. It’s a bit messy cutting into the fuel pipes and removing the old connectors so don’t forget to put something under the fuel filter to catch the muck. Start with the pre-heater pipes as they are quite easy: take the fuel feed pipe from the fuel filter (i.e. the one that runs from the fuel lift pump to the fuel filter) – don’t forget to remove and keep the connector and the banjo bolt as you’ll need to re-use them on your new pipe. Measure and connect the heat exchanger inline (fuel lift pump->heat exchanger and heat exchanger to fuel filter in).

Next work on the fuel line from the fuel filter to the injector pump. Again the heat exchanger needs to be in-line so work on the fuel filter->heat exchanger and then heat exchanger->fuel pump. Don’t forget to put the small see through fuel filter inline before the pump – this will give you an idea of the level of waxing and will show you if you have any air ingress into the fuel system.

Picture below is the basic unit with fuel pipes cut to size and connectors added.

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As the location I’ve chosen for my heat exchanger is easy to get to for the fuel lines, it figures that the location is also difficult to get to for the heater water. But with a few 15mm household copper pipes, bends and a blow torch I’ve put together something that neatly allows me to cut through the inbound heater matrix water pipe (that has give or take a 15mm internal diameter). So, heater matrix inbound hot water is cut about 10cm short and plumbed directly into my 15mm copper pipe work which runs directly into the heat exchangers water input. I’ve used rubber hose connections between the copper and heat exchanger to reduce vibration. Next a short run from the heat exchanger water out to the original water heater matrix input in the bulk head. I’ve used copper to give me a good neat angle and to avoid pipes rubbing or kinking.

Now in situ with water pipes connected (in-line via the heater matrix feed). It’s a little difficult to see, so I’ll do some better photo’s later.

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At the moment it’s all just water heated, but boy does it get hot! With 80/20 (diesel/veggie oil) and outdoor temperatures of 2-5 degree’s C in the morning it all works just fine*. Next up are the electrics – with those in place I should be able to run higher levels of veggie oil without any of the ‘cold start’ problems.

 

*the definition of fine in this case is a few (well a lot) of glow plug action before starting the engine and perhaps even a few attempts to start. You need a good and working battery!