Category Archives: Technical

Items of a technical nature relating to mechanical, electrical or bodywork issues

Fuel hoses

Anyone with a vehicle knows that fuel is really rather flammable. This is why you do not smoke at a fuel station. Anyone owning or driving an old vehicle should be equally careful with the state of the fuel “line”.

From the tank to the engine, the fuel is permanently sitting in metal pipe, plastic pipe and rubber pipe. There is no off switch, so if this ruptures, you are dumping the entire contents onto the ground, so from a financial point of view it is a sensible idea to ensure this is all in good order. From a heartache perspective, it is imperative as well.

You do not want your pride and joy catching fire due to a leaking pipe spraying fuel onto something very hot in the engine bay.

Taking the Type 1 engine as an example, there are multiple systems in place as primitive fuel emissions systems.

The U shaped pipe number 9 is the one that you can see on the roof of the engine bay in a Bay window just above the number plate.

Red pipe numbered 24 needs a long arm and can be reached by putting your left hand up past the rear light cluster up the side of the bus and is quite a tricky little one to replace. If you can smell fuel always, especially if you sniff the air intake on the left side, that is often missing or perished.

The ones next to the fuel tank in the picture by green 24 are all behind the fuel tank firewall and need the engine to be removed.

My local VW mechanic recommends replacing all of the rubber components at least every 3 years and last time , we found that blue 24 in the middle of the picture on the pipe heading to the right was actually disconnected, causing fuel to spill over the top of the tank when turning right with a full tank! We had a clean section of tank and a lucky escape.

In summary. Ensure that your fuel system is inspected regularly by a competent mechanic and relevant parts are changed. The new fuels have either Biodiesel or Ethanol in them, which are not good on modern rubber pipes.

Basic servicing of your air cooled vehicle

Step 1 Changing engine oil
Engine oils should be changed at 3000 mile intervals, to ensure that your engine doesn’t suffer from undue wear and tear. Some people even suggest that it should be changed every 2000 miles. If this seems a little extreme just think about how much it will cost to replace your engine should you have a catastrophic failure due to excessive engine wear! The actual oil change interval is up to you, but I wouldn’t recommend that you go more than 3000 miles. Always check you are using the recommended oil for your engine.

Step 2 Tyre pressures
It is important that your tyres are inflated to the right pressure. Your buses ride will be better and its road handling will be much improved, which also means that it will be safer. Check your tyre pressures at least every two weeks and always before a long journey. Make sure you know the correct tyre pressures for your model of VW Bus.

Step 3 Windscreen Washer bottle
The washer bottle on a VW Bus is located behind the front kick panel to the left of the steering column. The peculiar part of the set up is the fact that it needs compressed air to force the water from the bottle to the windscreen. You can attach a normal air line at your local garage and pressurize to 40psi. Warning, do not pressurize it any more than 40psi because you run the risk of blowing the pipes of the washer nozzles. It’s a lot of work to put them back on!

Step 4 Gearbox Oil
Although the gear box should only be changed every 30000 miles it may need topping up from time to time. The fill plug is located on the side of the gear box near to the clutch cable. The official documentation suggests you will need a 17mm Hex spanner, but mine seems to be 18mm! Use Hypoid EP80/90 gear oil and fill so the oil is level with the bottom of the hole. It is essential that you locate your bus on a flat surface when you perform this task.

Step 5 Spark plugs
Cleaning your spark plugs should be undertaken every 5000 miles or so. The electrode gap should be 0.7mm or 0.028in. You can clean the electrode with a little piece of emery cloth or a fine wet and dry. Personally I prefer to completely change my spark plugs every 10000 miles and check them every 5000 miles or so.

Step 6 Distributor Cap
When you replace or check your spark plugs it is necessary to inspect the condition of the distributor electrodes because they can become corroded. If so they can be cleaned or replaced depending on the level of corrosion.

Step 7 Rotor arm
The rotor arm (inside the distributor), should be checked, cleaned or replaced every 5000 miles or when you check the condition of your spark plugs. They are not expensive so I prefer to replace new for old on every service.

Step 8 Ignition points
The Ignition points should be checked every time you undertake the general electrical servicing outline above. The points gap should be 0.4mm or 0.016in and should be clean. If they are pitted or corroded in any way they will need replacing.

Step 9 Fan Belt
Check every time you look in the engine bay! Its easy. 10 – 15mm play is fine, anymore and you should adjust. There are some small shims that can be removed if the fan belt is too loose.

Step 10 Air filter (Oil Bath Type)
The air filter will need to be cleaned and the oil replaced every 5000 miles. Drain the old oil, clean and fill up with new engine oil. Make sure you dispose of your engine oil properly. Your local council will have an oil disposal unit.

Step 11 Fuel lines and hoses
Check the condition of your fuel lines every time you follow this service check list. If they are chapped in anyway replace them. Remember – no smoking! You can get very high quality steel lines if you prefer. Whilst you are doing this you can check the heater pipes for holes or badly fitting joints and repair if necessary. Having holes or bad joints will reduce your buses chance of keeping you warm.

Step 12 Brake fluid
Brake fluid should be checked and topped up periodically. The brake fluid reservoir can be found behind the front kick panel.

Step 13 Brake Pads
The brake pads can be checked very easily on a bus, although you will need to remove the wheels. To do this jack up the vehicle and remember to always use axle stands. You will be able to see if your pads need replacing, they should be at least 7mm thick.

Step 14 Axle
The axle will need to be greased every 5-7000 miles. There are multiple points that need greasing. These are the steering idler that is located in the middle of the axle and the four trailing arm bushes at the ends. So a grease gun will be a great buy!

Step 15 Clutch
Your clutch should be checked for play periodically and should have around 20mm play at the foot peddle. You should also grease the clutch cable periodically to help its ability to work efficiently and to stop it breaking because it gets stuck.

The engine battery

Prompted by a member called Robert who was asking, sharing in case it helps anyone else.

Robert had an issue with his starter battery and wanted to replace it but of course is space constrained in an older vehicle. His 72Ah battery was the right size, but how many Amp Hours do you need?

A standard 1.6 litre air cooled engine requires a starter motor such as the Power Lite one from JK. That one is a 1.4 kilowatt starter. Converting kilowatts to amps you need to change 1.4KW to 1,400 watts and then divide it by the voltage, in our case 12 volts.

1,400 / 12 = Around 120 amps.

For two litre engines, you will need a little more. For a customised engine, who knows?!

If you look at The battery charge quick reference guide you know that you do not wish to flatten the battery completely as that will break it. Ideally avoid going more than 30% depleted.

If you know that you never use more than a minute on the starter motor to get the engine into life, that is 1/60th of an hour. Running that 120 amp starter motor for an hour would be 120 amp hours, so 1/60th of that is 2 amp hours.

As long as you have no current leaks and are not sitting in your vehicle draining the battery with a stereo, a fridge, lighting or other circuits on the starter motor, as you can see, a minute to start the engine on a 1.6 litre air cooled engine will drain 2 amp hours out of your battery. Even the smallest and cheapest car batteries will cope with that, but for peace of mind, don’t buy the cheapest battery in the shop!

Metalworking – cutting bigger circles

Here is one that I did not know. I have drill bits that go from 1mm up to 10mm in 0.5mm increments. I needed to drill a 12mm hole in a panel that I had fabricated ready to take a grommet for a cable.

I checked in with a neighbour and he only had 10mm drill bit maximum as well, so I got online to order a 12mm and a 32mm one as well for another cable hole next to it.

Here is something called a hole cutter that comes as a pack of 3 allowing holes to be made in 2mm increments from 4mm up to 32mm. All 3 came in a little pouch for about £10.

And they worked so quickly I was rather surprised:

The 12mm hole on the right for the heater cable took about a second to cut from 10mm to 12mm. The one on the left needs the bigger cutter!

Inexpensive way of making lots of different sized holes!

Ageing your vehicle

If you have a Type Two, here is how to identify the age and type of your vehicle as it left the factory:

2 1 2 2 1 5 7 4 4

First digit – T2 (Bay window)

Second digit – Type of vehicle:

1 -Delivery / Panel van
2 – Microbus
3 – Kombi
4 – Microbus
5
6 – Pick up
7 – Crew cab

Third digit – The year (2 means 1972 and 9 means 1979 etc)

The rest is your individual serial number for the vehicle.

Replacing a sliding door seal without fully removing the door

by Mike Hobson

In October last year, I replaced the sliding-door seal, on my “crossover” 1972 VW Type 2. Despite being 71 years of age, I did it on my own, so younger members should find it a doddle! The tools needed, were a wooden spatula (as used by my wife in the kitchen), a selection of screwdrivers and an axle stand.
(1) Firstly, set the height of the axle stand, at as near as possible, to the height of the underside of the door. Pieces of wooden packing might be needed.
(2) Remove the cover plate from rear panel (covers sliding mechanism). This is where different types and lengths of screwdrivers are needed. You have to slacken the tightening bar (the screw can be difficult to get to). Once off, I drilled and tapped with the original thread right through, so can be filled with grease.
(3) You can now see the runner, about half way along is a cut-out. Line up with block on sliding mechanism and lift off rear of door and place on axle stands. Once done, presumably old seal will be out. Just hook new seal over projecting runner and then over door, move seal into position and door can be lifted back on to the runner.
(4) The wooden spatula is shaped as required and used to push the new rubber in. Adhesive can be used as required. It is a bit fiddly, but can be done. Adjustment to the door might be needed for it to shut, due to the thickness of the new rubber seal. It will eventually settle down. Job done.
P.S. I am no mechanic or engineer, just an old Joe Bloggs.

Experiences of overhauling a Volkswagen air-cooled engine

Compiled and written by Nigel A Skeet, previously published in the club magazine.

Sometime in early 1983, our 1973 VW 1600 Type 2’s AD-series engine, developed a major oil leak, which we were unable to trace; leading us to completely dismantle the engine and renew every conceivable oil seal and gasket, plus the steel, pushrod tubes, which were noticeably rusty. Although by that time, I had quite a good selection of tools, including two click-stop torque wrenches, none of them were suitable for removing the 36 mm AF, flywheel gland bolt, which is tightened to a very large torque.
Fortunately, one of my engineering-student colleagues at Cranfield, named Jonathan Wells, loaned me his ¾ inch drive T-bar and 36 mm AF socket tool, which he used for the rear wheel hubs, of his VW based, autocross space frame buggies. Even with this tool, one needed to slide a long steel pipe (being several feet long, it is referred to in some quarters, as a scaffold pole), over the T-bar, in order to produce sufficient torque. When we later refitted the flywheel bolt, we were faced with the problem of how to obtain the correct tightening torque (which is critical for this engine); not having a torque wrench of sufficient capacity. This was finally resolved by weighing myself on the bathroom scales and then standing on the T-bar, pipe extension, the appropriate distance from the socket centre; ensuring that the pipe was horizontal.
Ten years later, in 1993, when we sold the 1600 engine, second-hand, in favour of a VW Type 4 style engine (the virtues of which, Jonathan Wells had extolled to me, in 1983), the buyer recounted a tale of woe, about his supposedly “reconditioned” 1600 exchange engine, whose flywheel bolt had not been adequately tightened. The flywheel subsequently came loose, resulting in a severely damaged engine, which was effectively written off.
On the whole, removing, dismantling, rebuilding and refitting the 1600 engine (my first ever attempt at such things) was child’s play (in many respects, simpler than doing a 200 piece jigsaw puzzle), but removing some of the cover-plates was a nightmare. Many of the cheese-head, slotted M6 screws had rusted in solid and needed to be drilled out very carefully. Noting that the screwdriver slots of conventional and Philips head screws were easily damaged, I later replaced them with 10 mm AF, hex-head M6 bolts, which would withstand higher torque. At a later date, I took the further precaution of coating the screw threads, with anti-seize copper grease. These days, I would also be inclined, to substitute stainless steel bolts and/or Allen socket-head screws, which are what I am using, on my transplanted VW Type 4 style engine.
Many of the cover-plates had corroded where they were exposed to the elements; having been given only a thin coat of paint at the factory. In some places, the steel had become wafer thin, necessitating repair. All the cover-plates were comprehensively treated with D-Rust (a phosphoric acid based rust treatment solution), to etch all the rust out of the pits, and repaired as necessary, by brazing on reinforcement sections, before repainting them with several coats of Finnigan’s Hammerite. When I sold the engine in 1993, these cover-plates were still in excellent overall condition, which I have since sold off piecemeal, during the following years; some as recently as 2010~12!
Removing the old exhaust silencer, proved to be no picnic either, and it was necessary to use a hacksaw and cold chisel, in order to disengage it from the heat exchangers. Had removal of the exhaust silencer not been necessary, it would probably have lasted a few more years. The original exhaust-manifold nuts, incorporated HeliCoil™ thread inserts, which did not rust, but the hexagonal outer portion had corroded badly and no spanner (neither metric nor imperial) would fit them snugly, so “copper exhaust-manifold-nuts”, were purchased as replacements.
We did initially obtain a stainless steel replacement silencer, from the local branch of Qwik Fit Euro, but this would not align correctly (may have been intended for a VW 1200 engine!?), with the cylinder head exhaust ports and/or the heat exchangers, so it was returned to the suppliers. Ultimately, we fitted a Scat ‘Monza’ style silencer, with two integral twin tail pipes, from the USA, purchased from the German Car Company, in Hadleigh, Essex. This lasted well, for nearly 8 years, until Easter 1991, when one of the twin tail pipes dropped off, somewhere on the M40 or M25 motorways. The so-called “copper exhaust-manifold-nuts”, which had been fitted nearly 8 years earlier, proved to be merely copper-plated steel nuts, and had rusted onto the screw studs; one of which sheared off and resulted in the need for an expensive repair to the cylinder head.
I had never been impressed with the standard, single-piece, exhaust-silencer clamps, intended for the VW 1600 Type 2, so instead I used a pair of two-piece, VW Beetle tailpipe clamps, which are more fiddly to fit (see Transporter Talk, Issue 27, February 1997, Pages 24~25), but provide a better seal between the heat exchangers and silencer. To be sure of a gas-tight seal, I also used a liberal quantity of Holts Firegum; a well-known brand of exhaust system sealant.
During the engine strip down, it was discovered that the valve guides were excessively worn, so the cylinder heads were taken to a local engine reconditioning workshop, in Basildon, Essex, for refurbishment. This proved to be yet another encounter with shoddy workmanship, resulting in one of our cylinder heads being consigned to the scrap bin. It was alleged that the damage had arisen, as the result of some earlier bodged attempt at replacing a single valve guide. The workshop manager disclaimed all responsibility, and showed us a cracked exhaust port, together with a rough-hewn valve guide, which had supposedly been removed from it. In our own minds, we were convinced that this was a deliberate falsehood, but could not prove it!
The cylinder head also exhibited deep bruising of the cooling fins, consistent with violent blows from a large ball-peen hammer; marks which we knew had not been present, when we submitted our cylinder heads for refurbishment. As a consequence of this episode, we were obliged to purchase a new, replacement cylinder head, from another supplier. Although this was for a VW 1600 engine, with the same sized valve heads as the original, the exhaust valve stem diameter was 9 mm, rather than 8 mm. I suspect there may have been other, more subtle differences, which were not apparent to my then untrained eye.
Such differences, may have contributed to cylinders 1 & 2, running hotter than cylinders 3 & 4, which I noticed some years later. Since then, I have learned that there are at least nine different VW 1600 ‘twin-port’ cylinder heads, with three different, standard combinations of valve head sizes, plus probably various differences in combustion chamber shape, volume and deck-height (i.e. squish or quench) clearance too. With hindsight, we should have noted the part number, cast into the rocker box of the defunct cylinder head (assuming it was originally ours!), but in those days, we believed there was only one type of VW 1600 cylinder head and were unacquainted with the significance of the suffix letters, in VW part numbers.
Whilst the engine was still out, it was a good opportunity to remove and inspect the petrol tank, which exhibited some corrosion around the fuel outlet, beneath the vehicle. Although there was slight pitting in places, the thickness of the steel had not been significantly compromised, so it was sufficient simply to etch out the rust pits, using D-Rust and repaint the refurbished surface. Other areas of the petrol tank were also showing signs of superficial rusting, which were similarly treated.
Having removed the bulkhead plate to gain access to the petrol tank, it was apparent that this too was rusting in places, so this was also refurbished before repainting. In common with the engine cover plates, the petrol tank and bulkhead plate, had received only a thin coat of paint at the factory, so all items received several coats of Hammerite; paying particular attention to those areas, which previously had rusted.
Prior to painting, I had twenty one, captive M6 nuts (with hindsight, M5 nuts might have been better!), welded onto the back of the bulkhead plate, coinciding with the top, middle and bottom, of the seven vertical ribs; anticipating that at some time in the future, I might wish to fit, electronic ignition and perhaps other accessories, which would need to be mounted in the engine compartment.


1973 VW 1600 Type 2, removeable fuel-tank compartment bulkhead, with nineteen M6 nuts, welded onto the back of the seven vertical ribs.
Note also, the additional holes in the bodywork, on either side of the bulkhead, for supplementary electrical cables, pipes or hoses, to enter the engine compartment.
Any accessories could then be fitted, using custom made mounting brackets; avoiding any later haphazard drilling of holes in the bulkhead (which might penetrate the petrol tank), to accommodate self-tapping screws. About ten years later, a local VW Type 2 owner of my acquaintance, who sadly lacked this kind of foresight, somehow managed to drill three holes in the forward face of his petrol tank, when fitting secondhand motorcaravan furniture, in his Microbus. Fortunately for him, I had a secondhand petrol tank for sale!

Fitting a Voltmeter

In many campervan conversions, keeping an eye on battery voltage can be a very handy feature, especially if you are camping without electric hook-up and have an electric fridge, lighting etc.

You can connect the voltmeter to either the main vehicle battery, used for starting the engine and supplying the vehicle’s 12v electric systems. Connecting the voltmeter to a leisure battery will enable you to see the voltage remaining in your battery for auxiliary accessories such as lighting and fridges. Or you can purchase a switchable voltmeter that enables you to see both battery voltages at the flick of a switch, like the one sold by Just Kampers (J11477).

• Before installing the gauge, disconnect the earth terminal from the main battery in your vehicle and from the leisure battery, so that you do not create any short-circuits which may result in damage or fire.

• Choose a location to mount your gauge, allowing enough room at the rear of the gauge.

• Connect the negative/earth wire on the back of the gauge to an earthed part of your vehicle, such as a bare metal part of the chassis.

• Run a fused wire from one of the positive terminals on the voltmeter to your vehicle’s main battery live terminal or a live terminal on your main fuse box.

• Run a fused wire from the other positive terminal on the voltmeter to your leisure battery live terminal, or to a live terminal on an auxiliary fuse box connected to your leisure battery.

• Reconnect the earth connections on your two batteries that you removed earlier.

• When you have selected either switch position, the gauge should now read the correct battery voltage for that battery.

• Sit back and enjoy the luxury of being able to monitor your batteries voltage levels.

Aircooled engine cooling

When summer is here that hopefully means that we are experiencing warmer air temperatures. With warmer air temperatures, comes warmer engines. Those using aircooled engines will find it even harder to keep the engine cool during the summer months and we have all seen the odd VW at the side of the motorway! Don’t let that be you (not through overheating anyway!)

The tinware on a 1.6 Type 1 engine

Although it may seem like a small detail, to ensure cooler engine temperatures, it is absolutely vital that the tinware and engine compartment rubber seals are all present and intact. This ensures that there is cool air above the engine and hot air below it. These are known as the cool and warm zones. If tinware parts are missing, or the seals around the front and back of the engine are torn or broken, hot air will be drawn from the cylinder heads and exhaust back into the cool zone around the top of the engine and then sucked in by the cooling fan and re-circulated over the cylinders and heads, causing the engine temperature to rise, potentially to a critical level. This can cause all kinds of problems over time, some of which may not be immediately obvious, from hot starting troubles, to cracked cylinder heads, up to and including a seized engine.

If you’ve just bought a car/bus, it is well worth checking the condition of the tinware and seals and also making sure that there are no foreign bodies stuck in the cooling fan (remember to do this with the engine turned off!)

If you are fitting a reconditioned or new engine, don’t just rely on refitting the parts that were on the old engine, as they may not be correct either.

The thermostat is another vital piece in the cooling system. There is a set of flaps inside the fan shroud, that actually block cooling air when the engine is cold, in order to warm up the engine more quickly. These are opened by the thermostat, located between the cylinder barrels and if this part is defective your engine will very quickly overheat. Check the function of the thermostat and flaps and if required, replace. The alternative is to completely remove the thermostat and flaps, which while it certainly simplifies matters, is not ideal. It means that your engine may never reach the correct operating temperature in cold weather conditions.

The last few points to consider are your ignition timing, air leaks and fueling. Poor ignition timing can cause your engine to run too hot, it’s unlikely to be visible if it’s wrong but you should hear it. Fuel mixture is equally important, so ensure the carburettor jetting is correct for the size of the engine, fuel starvation will raise the
engine temperature internally. Your fuel system could be setup perfectly, but if your engine is sucking air in elsewhere through a split hose or a broken gasket, then the whole fuel/air mixture is compromised and the chances of running lean and therefore hot, are increased too. Spraying the intake system with Wd40 whilst running will help to detect this, an air leak will suck the spray in, using it as fuel and changing the engine note at the same time.