Bush Mechanics

Introduction: Bush Mechanics

Bush mechanics

Just the word strikes fear in to folks and conjures up images of toothless wonders with greasy hair, raggedy clothes and oily rag dangling from his back pocket, stooping over your pride and joy where you have broken down somewhere between the hell and the tall grass. Fact of the matter is that if it wears a skirt or has four wheels it will give you trouble and cost you money, weird stuff happen to good people and if you don’t know better that toothless wonder is probably your best bet to reaching some sort of civilization. With a bit of knowledge and a lot of ingenuity you can get yourself out of a sticky situation without too much stress and as an added bonus the weef will think you are the proverbial knight in shining armor. I just need to make one point; bush mechanics are not backyard mechanics. Backyard mechanics are normal parts fitters working from home where as bush mechanics get you going with what is at hand, the difference is ingenuity.

Ingenuity and determination alone is not going to do the trick, you will need some tools. The cheapest rubbish is better than not having any but I would recommend getting a fairly decent set of tools. It does not have to be Snap n quality but the pressed steel excuses that one finds in the fancy plastic boxes with 101 bits in does not cut it, they are designed to be bought by lay people and to spend their time tucked away in some cupboard, never to be used.

Firstly you need a set of ring set spanners from 8 to 19mm. these are the ones with a ring on the one side with an open end on the other side.

Next follows a set of screw drivers with flat and star points.

Throw in a sturdy pair of pliers and a sharp side cutter and you are halfway there.

The above mentioned tools are what I would consider as being the bare minimum, I have a canvas roll that all fits in to as permanent residents in my Pajero. Tip Take the weef’s sewing machine and sew a canvas or fabric rollup caddy for the tools, it not only keeps everything together and stops it from rattling but also enables you to spot anything missing when you have finished working.

To expand the basic toolset I would add a good shifting spanner and gas pliers. These are two tools that you really don’t want to skimp on as it can create more problems than it solves. The cheaper units do not grip the bolts properly and are prone to slipping and in the process rounding off the shoulders of the nuts or bolts not to mention the bruised knuckles and blood loss that accompany these little slips. Another essential is a decent wheel spanner as the last thing you need is for the cheapie that came with the vehicle to break leaving you staring at the flat wheel on the car while the perfectly serviceable spare remains firmly on its bracket. I use one of these extendable units that can double as a ½” drive power bar. Tip invest in a 24 socket as it is needed to remove that plough of a tow bar of yours when doing the off road thing. I have found a very nifty set of box spanners at Midas that come in handy when access is compromised. Allen keys are another one of those handy bits to have and do not take up too much space and with a pair of long nose pliers and a couple of vise grips should round off the toolset.

You will notice that on the smaller sizes of spanners I carry doubles as one often have a bolt and nut of the same size and you need two spanners to loosen it.

That should take care of the basic essential tools and with a few nice to haves and essential spares you are on your way to becoming a self sufficient bush mechanic.

Henk

Spares, Bits & Pieces

As with the tools, the quantity of spares you carry depends on you and your vehicle. For a series landy you would require a lot more than for a Pajero and I am going to list what I feel is essential. The danger with spares is that you could end up needing a truck to transport it all. I must point out that this list is aimed at petrol engines, as for diesel I have no experience.

Starting from the front: Spare lamps for indicator, headlights and tail lights

If you have spots a spare for them as well.

Full set of fan belts. We all know the myth of nylon stockings. It does

not work it is a myth.

Radiator hoses (both)

Spare thermostat

Spark plugs

Spare rotor and dizzy cap and the longest ht lead spare.

Oil and fuel filter as well as 1m fuel line & clamps.

Fuses.

Other bits & bobs

Workshop manual for your vehicle

Oil for engine, gearbox & diff as well as power steering

Q20 or similar

Insulation tape (good quality e.g. Nitto)

Some electrical wire & resin core solder (I carry some plumbing solder and a bit of flux as well as it has very good capillary action and seems to melt at a lower temperature, flux = corrosive)

Cable ties and binding wire (non insulated hard steel)

Selection of bolts and nuts & bolts 6 – 10mm. Washers & split pins.

A few pairs of surgical gloves (it is handy to throw away the dirt after changing a tyre)

Tyre repair kit

Silicone gasket maker

Pratley putty and epoxy

Some metal sandpaper 80 & 600 grit.

A piece of waterproof tarpaulin about 2m X 2m to work on.

Playing

I think that is enough toys for a start let’s start playing with them.

The best bit of advice I can give you is to get to know your vehicle before you get stuck.

Picture this, you are driving along enjoying the trip and when you look down the battery light is glaring at you……..Not good, without power being put back in the battery, the engine will die in about 80 kms or roughly 90min as you have no ignition and your computer will shut down. You pull over and open the bonnet.

1st option the fan belt has snapped. That is why you carry a spare. Let things cool a bit while you get the replacement belt and tools.

Slack off the tensioners and fit the new belt and check for any damage, sharp edges on pulleys and such. If any, use your sandpaper to smooth things out. The workshop manual comes in handy to route the fan belt and advice to tension for the new belt. Tip If you start the engine and rev it up and the belt screeches at you the tension is too low, tighten the belt more without over tightening it. For squeaky noises from a new belt check that is not too tight, if not apply a candle to the underside of the belt while the engine is running, the wax will lubricate the rubber without damaging it. Watch out for your fingers and the fan blades. That was the easy one.

2nd Option. Belt ok and the alternator turns with the motor. Now things are getting interesting.

1st Check the electrical connections and make sure there are no burnt wires or terminals.

2nd Check that you have 12v on the alternator as an alternator needs power to make power.

3rd Last resort it is probably brushes worn out or voltage regulator (unlikely). Brushes wearing can be diagnosed by the charge light coming on dimly for a while and going off when revving the motor.

Unfortunately there is no other way to confirm your suspicion other than removing the alternator and opening the unit. On Bosch alternators (#2) one can remove the voltage regulator and brushes as a unit without removing the alternator but the mitsu ones (#1) I have seen needs to be stripped. Once again the manual comes in handy. Disconnect the battery BEFORE you start working.

The horrid moment has arrived. You have opened the alternator and found the brushes worn down and your toolbox is not the local Midas that is 300km away. You do not have as spare set of brushes and you are stuck. Not so, the bush mechanics on page dirty advises:- Grab the first torch with normal batteries in and take one of the batteries out. Note it must be a normal and NOT a rechargeable battery. Normal batteries are zinc carbon units and the carbon is exactly what we need. Use a side cutter and remove the outer cover of the battery. Do not worry as there is no battery acid or messy stuff inside and we do not go deep enough to get to the paste.

Looking at the photo you will see that it has a metal outer cover and then a plastic inner cover followed by a cardboard housing. In the center there is a carbon rod that makes up the positive of the battery. This is what we need and it just slides out with a bit of gentle persuasion.

Cut to length and sand down to the correct shape and viola you have a new brush.

Cut the old brush off keeping as much of the wire securing it to the unit. This is wedged under the spring and the new brush is inserted in the holder and the alternator is reassembled. On the mitsu alternators you will find a small hole on the back of the unit. This is to insert a short piece of stiff wire to hold the brushes away from the slip rings and helps with reassembly.

This carbon rod can be used for any kind of brush and although it will not last for 100,000 km, it will get you out of trouble, it is fairly brittle so handle with care but shapes well on just about any rough surface, stones and concrete fence poles even on rusted steel.

Trick #2

You opened the bonnet and found one of the wires burnt off or a connector burnt. Time to get out the solder and either, bypass the connector, or solder the terminal back on to the wire.

Wires burn because of loose connections carrying a lot of current and then arcing, I have never found a wire that has burnt off in the middle of the run, it is always at a connector or termination. Clean the terminal using sandpaper and cut back the burnt copper to healthy wire. The secret to a good solder joint is clean surfaces and enough heat. No soldering iron? No problem. Take your solder and pinch it flat using your pliers then wrap it around the joint. Use a normal bic lighter to heat everything, as soon as the correct temperature is reached the solder will melt saturating the wire and joining on to the terminal, let cool and tape. The joint should be shiny in appearance indicating a good joint. If it is dull in appearance it is probably what is known in the trade as a dry joint where the solder does not adhere to the base causing a bad connection that will burn again.

The next little imaginary
scenario I want to explore is just as intimidating and as important as electrical power, cooling.

Driving along and enjoying the fresh Karoo air and you notice the heat gauge is creeping alarmingly higher and higher. This can be something simple as a broken fan belt or something much more serious either way do not ignore this and hope it will go away. Pull over and investigate. Most water pumps run off the fan belt and will stop working if you lose the belt for any reason, others like Mitsubishi run off the cam belt, if you lose this one the engine will die and you are in a wee spot of bother with a very good chance of serious damage to the engine. Never take chances with a cam belt. If it is up for replacement do it sooner rather than later, the cost is a fraction of the possible expense of failure.

Next point to look out for is a possible leak or burst pipe. If it is not a major leak you might see a stream of water squirting from the offending part such as radiator or a water pipe.

A burst radiator hose is easy to replace just undo the clamps and remove the old one, replacing is just a reverse operation. Be careful with the cooling system as the normal operating pressure increases the boiling point of water and if you open it and the pressure drops suddenly you will be met with a column of superheated steam right in your face, not pleasant. Rather let the engine cool for a while, with the bonnet open, while you have something to drink yourself.

A burst heater pipe or similar is a bit more difficult as you would probably not have a spare handy, this is where the bush mechanics comes in handy. Remove the burst pipe and if the damage is close enough to the end and you have enough slack in the pipe simply cut off the damaged end and refit, if not, that tyre repair kit that you bought is going to come in very handy now. Clean the area with a bit of sandpaper to get a good bonding surface and select a patch of suitable size to cover the area. Apply some solution and stick the patch over the rupture. Reinforce the area by binding it with insulation tape wrapping it tightly around the pipe.

A leaky radiator is not a nice thing to repair in the bundu but not impossible. It is the same as eating an elephant, one bite at a time. Small leaks can easily be promised right by adding some chili powder or cayenne pepper to the radiator. It will leak to start off with but as the small flakes get pushed out the hole some of them become trapped and eventually the leak is stopped. Once back in civilization the system can be flushed and the radiator repaired properly. There is a myth about egg white doing the same but I do not trust it as the temperature needed for the egg to coagulate is higher and the particles can block the water channels, in a push mielie meal would do the same job but, it too, has bigger particles.

The core of the radiator is where the plumbing solder comes to its full use. Being a capillary type of solder it would naturally creep in to any little crack and crevice as long as it is clean. Plumbing flux has a pretty strong acid in it and does a good job of preparing the metal as long as you have cleaned the paint and gunk off the area. You would need a bit more heat than a bic lighter and a mini butane torch would b very handy as the heat can be controlled accurately otherwise the good old Cadac stove will work in a push. You will need to remove the radiator. Be careful as some newer vehicles have plastic header tanks and these can be damaged by heat creating more problems. If the damage is close to the header tank rather use epoxy to seal it and run without your radiator cap.

If you find that the leak reappears when the motor runs under pressure and you cannot get it to stop also remove the pressure cap on the radiator and make your way back to civilization cautiously. Keep an eye on the temp gauge and stop regularly to check water levels. An engine that overheats can pop a cylinder head gasket and create all sorts of unpleasant nasties so keep your eye on that temp gauge. I am a big fan of after market gauges as the factory fitted ones do not give accurate readings and tend to respond slower to variations.

If you find no obvious reason for the increase in temperature it could be that your thermostat is faulty. The simple remedy would be to whip it out and drive without one but this is not the case. The thermostat is not only there to get the motor to working temp. quickly but also to act as a restrictor in the cooling system and to slow down the flow of water in the radiator. Without this restriction the water flows too fast through the radiator and does not cool adequately resulting in temp. rising unnecessarily. Remove the thermostat and cut the centre portion from the rest. Replace the outer half in the housing and refit. This would give you the required restriction and get you back. If you damage the gasket while removing it is a simple fix. Any kind of cardboard like the side of a cereal box or the cover of a book can be used to make a new one. This can be sealed with a bit of grease or Vaseline or even some of the weef’s thick night creams. I do not like to use silicone gasket maker on aluminum and water as it tends to rapidly corrode the aluminum creating more problems down the line.

A new gasket can be tapped out quite easily by taking the housing in the one hand and covering it with the cardboard. With the other hand take a small hammer or even the side of a large spanner and gently tap around the edges. The sharp corners of the housing will cut through the cardboard leaving a perfect copy in cardboard, voila, a new gasket. The secret lies in taking it gently, you don’t want to smash off corners on the housing so don’t hurry.

Making a gasket in the bundu is not as difficult as people think, if your surfaces are nice and smooth and mates well you don’t need a very thick piece of cardboard and even a nice thick piece of paper will do the trick. These make shift gaskets can be sealed with a variety of stuff. Good old Vaseline is good for most areas as is bostic, avoid using silicone on any area where it can come in contact with petrol as it turns in to a gwabby mess.

Another little setback that can spoil an outing is picking up a crack or leak in a sump or petrol tank after over enthusiastically negotiating an obstacle, the last thing you need is to lose those precious fluids. A small tear or hole in a sump can be repaired without the need to drop the sump by cleaning the area with sandpaper and stuffing some Pratley putty in the dent and hole, once this has hardened clean the area around it and put a bandage or patch saturated with epoxy over it. This should see you back to civilization. A petrol leak is not so simple as petrol will seep through cracks that water cannot and will attack most sealants winning the battle hands down. The solution is as simple and old as the hills, normal bath soap. In the old days the green sunlight soap was the best but as times progress we have to make do with normal bath soap. Rub as much soap in to the crack or hole as you can and keep in place with a bit of epoxy on a patch. The secret is to work as clean as possible as any petrol left behind on the surface will form a capillary bridge and you will have to start again Any fabric can be used as a patch as it is only there to reinforce the epoxy. NEVER try to solder the tank with an open flame it is a BOM and will seriously hurt you. As a permanent fix get a professional to do the work. Welding and brazing fuel tanks is highly specialized and definitely not for anyone other than a specialist.

The secret to any situation is to remain calm and level headed. Let’s face it you are stuck and now it is up to you to turn this situation in to another adventure. Work slow and meticulous even if it just a temporary repair as this is your ticket back to civilization. Rushing in and a slap happy job will only result in doing it again and maybe even more damage.

Motor Vehicle Contest

Participated in the
Motor Vehicle Contest

Be the First to Share

    Recommendations

    • Summer Fun: Student Design Challenge

      Summer Fun: Student Design Challenge
    • Backyard Contest

      Backyard Contest
    • Metal Contest

      Metal Contest

    Comments