Thread: Progress on My Unimog

Almost a year since my last update. I have done a lot of work, but after my wife got sick, I did not spend anywhere near as much time as I used to. When most of the treatment, operations and reconstructions were finished, we needed some time away, so we went on a a three month trip around Australia (Our three month lap of Australia

Now we are back, and things are going better, now time to get stuck into the truck, and hopefully get some real progress done.

First to recap progress over the past year:

plumbing and the electrics.

I've installed the hot water heat exchanger, I had to made a frame to get it off the floor, so that all the pipework will fit, otherwise it would be too difficult to get to. Next was to run all the water lines. The system is fairly complex.


The supply system consist of:

Two water tanks
Two independent supply lines
Two pre-filters
Two water pumps
Filler system (common fill point but with each tank isolated)
Air breather system on each tank connected to the fill point

The 20 litre hot water tank is heated by the engine cooling system, or the Webasto diesel heater. The on-board cabin heater is also part of the system, with isolation valves on the heaters to block it off when it is not required. As the engine can heat the tank to over 88 degrees, I have to fit a tempering valve - that blends the very hot water from the tank with cold water to reduce the temperature down to 40-50 degrees so it doesn't burn you. Since the water in the tank gets very hot, it expands, so there is also a expansion valve to bleed the excess pressure.

The delivery system consists of::

2 shower heads ( hot and cold - one in the entrance way, the other in the boot - which doubles as the outside kitchen tap)
Sink ( hot and cold)
2 drinking water taps (connected to the Seagull IV filter - next to the sink, and another tap in the boot.
Outside hand washing tap ( front passenger side - cold only)

This shows the outside tap, can't see it unless you get under the truck, when the fuel tank is in, it will be hardly noticeable for outside unless you are really short. We can also switch it off from inside the truck.



There is a quite a lot of fittings required to get the rigid lines around the various compartments, and I have to keep the pipes accessible, but also out of the way. I'm using the John West system of push fit fittings. The fittings can either be a simple push on fitting, but that would be a bit too easy. The best way of doing it is to use inserts on ends of each pipe that reduces the possibilities of leaks, then locking clips to hold the fittings in the full lock position to stop them from coming loose over rough roads. So each pipe has the extra fittings, means you do everything twice, making everything fit, then taking all the pipes off again to fit the inserts, as once they are in, you can't take them out if you need to trim the hose a bit.



Next off the interior of the camper. This has been a long and drawn out saga, to date almost two years in the making, but it is getting closer.

The fridge slides and all the drawers are all in, The slides have a catch mechanism that keeps the heavy fridges in place. The drawers for pots, pans etc are made from 3mm aluminium, so they can handle the load. They are pretty big, so should be able to take all the gear and the day to day food supplies.



The rear locker is also in, and so is the sound system. After a bit of modification and stiffening, the sound is really good. I has also fitted the fans, the first ones I fitted were pretty noisy, the locker amplifying the sound, so I got some I tried fitting a rubber pad, but that did not do much good. After a bit of research, I found what was rated as the quietest fan on the market, the Camframo Sirocco fan.



Whittworths had them on special, for only a bit more than I could have bought them Overseas, so I headed off there and bought a pair. What a huge difference, they are really quiet on low speed, and have a faint hum at full speed. They fold flat against the back as well, and even have a timer from 2 - 8 hours.

I also fitted the toilet slide and the door of the toilet, but there was a problem as the hinge is about 3mm proud of the side of the door (there is a strip to cover the edge) as the lightweight panels are only 12mm thick, and the hinge is 15mm. Unfortunately that mean the toilet slide did not work properly - hitting the hinges, so I had to reposition the toilet slide so it would work. An hour of two of repositioning and refitting, and we have a toilet. As usual, there was a problem, the little handle that you move to direct the flow to the solid or liquid containers would hit the door. So that hand had to be cut off, and a lower profile handle made that I put in the inside, out of the way. At last the whole thing was functional. Now to make the catch to hold the slide in position so it is not putting any load on the door.



The radi needed an external amplifier, as it generated too much heat inside the control panel cabinet. The good side is that the sound is even better with the amplifier.



I'll post more photos and reports a bit more often now that I'm working on the truck a lot more.

Just finished my automatic steps for the camper - one of the many requirements if you want your truck registered as an RV here in Queensland.

I used a Warner 12 volt Linear actuator Model number DE12-17W41-05FP015 with a 5 inch stroke. It is IP56 rated and has a maximum force of 120lb/55kg.

The actuator has build in limit switches, and a static lock of 220lb/100kg. The stair is over-centre locked, so even if the actuator fails or falls off, it is unlikely to fall open, as it needs about 15kg of push force to overcome the first bit. There is a simple switch, a DPDT switch wired up so one way it extend, one is retract. Extended has a warning light which I use to trigger a warning buzzer is I try to drive off with the step down. I'll use the clutch switch to energise all the warning circuits, as there will be others like the rear locker or the boot being open.

Pretty happy with the result, now I just have to take it all apart again, fit the aluminium stair treads and make it look pretty I'll use teflon washers on all the joints to make them as smooth as possible, and fit lock nuts to all the bolts. Everything is a pretty loose fit except for the joints around which the steps rotate, they were the most difficult to align, especially when welding tends to pull things when the metal shrink. My philosophy has been to build things like an AK47 rather than an M16, lots of clearance and a little precision as possible and still functional. Two reasons, first as a Civil Engineer, is we get things within a centimeter we are doing well and my fabrication talents don't extend much in the way of precision fit. The second reason is that things wear, and is they need tight tolerances, then they tend not to last that longer in the dirt and mud.

[ame="http://www.youtube.com/watch?v=t74VJEgm1a4"]IMG 0007 - YouTube[/ame]


Now I can make up the template for the grey water tank that goes under the shower.

Originally Posted by Iain_B

Just finished my automatic steps for the camper - one of the many requirements if you want your truck registered as an RV here in Queensland.

...

That doesn't seem fair. What if you want to keep things simple, and just have manual pull out steps?

What is the benefit of having it registered as an RV? Here in SA, the rego for 1 year is either $1500-ish for a truck or $1300 for a campervan, so there's not a lot in it.

Manual steps are "external fixtures" so not allowed

Rego here is around double for a truck, and you need a annual roadworthy test as well. When we go overseas, it would be pretty hard to get the roadworthy

Time for another update. Things have been happening, allow sometime it has been two steps forward and three steps back.




First off is the camper heating system. This has to have been one of the must frustrating parts of the build to date. It has taken an extraordinary amount of time, and I've done thing three or four time, and still not got it right. Finally I can say that I think it is in to stay. The diagram below shows the basis of the system. I explained how it works in the last blog post, so I won't go into to again. The main problem has been with the number of stainless steel fittings, and getting the joints to seal. I have had threads fail, "galling" is the technical term and stainless steel is very prone to galling. It occurs when you tighten up a joint with lubrication ( I can't lubricate or the sealer won't stick) When you try to loosen it off again, the threads bind up and you can't get it undone. This is very frustrating when it is something I need to undo to get to be able to get the manifold out of the truck.

I decided to us the Loctite thread sealing system, this was recommended to me by the suppliers and other people on the net. It was definitely the wrong decision. Loctite will set up within a few seconds once the threads are tight, only problem for me is that I normally have to turn the joint to get it to line up, and in that few seconds it takes to check that it is properly alignend, the sealant has hardened. Now if you are a 1/4 of a turn out, and then tighten it up a bit more, the sealant then leaks. I found this out the hard way by getting everything installed, and then testing the system with air. About 10% of the joints leaked. So then I had to take it all apart again, and that when the sealant had done it's job and it was very difficult to undo. It would sometimes take me half and hour to get one fitting loosened, and all my strength just to turn it a tiny bit. It was so frustrating I did not take any photos, but did remember to take one of a leak in the return manifold in the boot when I was testing it. I pumped the whole system up to 4 bar, and sprayed soapy water on each joint and bubbles form where there is a leak. I changed over to PTFE tape, a heavy duty pink tape I have been using on other parts of the camper water system with great success and no failures so far. In hindsight I should have just done that from the beginning. This time I tested each section before I put it in. Finally, around 11:30pm on Thursday night I was able to say that the system should now not leak. I hope this is the case, I'll see once I get water in, it is air tight to 4 bar, and that is four times the pressure the radiator runs at.


On a separate note we decided to buy a little induction hot plate. $60 off eBay, and I put it to the test. It is really quick, boiling the same 1 litre of water in old 7 minutes, less than a third of the time of the diesel stove. The downside it draws a massive 185A. This means it is not really a practical solution for cooking unless we are running the engine.





In between the frustration of the water system, I decided to do a few jobs I had been putting off for a long time. First was the stay on the tool box compartment. With a bit of fiddling and some new brackets, I got the Jaguar XJ-S pneumatic boot stays I have had for years fitted. One is enough and whilst it took a two goes to get the right angle. length etc. It works and fits nicely. I have a spare stay as well.



I also fitted all the clamps and support for the brake lines and airlines on the axles and torque tubes, fitting the breather lines for the diff, the air handbrakes and various other things that can suck in water if they were used when we were parked up in a river or something. Rerouteing some of the line led me to discover another problem. I have been using the ARB compressor to top up the air system to release the handbrake whenever I want to move the truck or just to check for any air leaks in the system. I decided to re-route one of the lines, and discovered the was a lot of water in it, and some of the fittings were starting to rust already and that was on the airline going straight into the Wabco dryer. This is not good, as it means that the the dryer will get used up quickly. The problem is the high humidity over hear, close to 70% some days. I looked in to various solutions and decided the best way to go was to install the "wet tank" before the dryer. Previously I had put this after the after the dryer, to catch anything that got through the dryer. I did this based on recommendation from a few other people who have a wet tank just after the unloader valve. I spoke to Air Brake Systems who have been supplying all the parts for this build. They said it would be a good idea to install the wet tank before the dryer, as this would greatly increase the life expectancy of the dryer, and prevent contamination of the desiccant with oil as well.

It was a bit more difficult than just changing over a few air lines. A proper wet tank has be be vertical, so that it can do a good job in separating the water/oil out. This meant I had to reposition both the wet tank and the purge tank which I had mounted horizontal. Finding a new home for it proved fairly difficult. Eventually after much crawling around and hitting my head numerous time on various parts of the the chassis, I found a good spot, mounted on the rear plate, right at the back of the truck. It fits nicely, with all the required clearance for camper movement, suspension and frame movement. It only require a flat bracket with no welding, just a bit of a bend. Drilling the holes in the rear plate was not so easy, but made possible at least by my right angle drill.





There was no space for the purge tank with the wet tank in this position, but I found a good spot for it under the front of the camper which solves another problem of the fuel filter being easily visible from casual passers-by. The original bolts were too high up to use, so I tapped in four 8mm threads into the support bracket, and fixed it to the underside of the camper through the checkerplate. Four stainless steel countersunk screws and it fits very nicely out of the way.


As you can see I have also been busy fitting up the fuel system. This took quite a bit of figuring as like all things on this truck it is pretty complicated. This is the system I have come up with.




From the fuel tank, fuel is drawn up into a 100 micron washable filter. This filter is to protect the Facet pump. The Facet pump has two uses, first off to prime the system. This enable us to bleed out air should we every run a tank dry pretty easily. I have one on my Discovery Tdi and it makes changing filters or sorting problem like air leaks very simple. It will not be needed when the engine is running, as the lift pump is capable of drawing fuel out of the tank, but it will sure make it easier to prime the system. I had to get some pumps in from England, as the total lift require is around 60cm. The ones sold here can only lift around 30cm at best, I know because I have one and it struggled to prime itself out of a jerry can with only around 25cm of lift, taking about 10 minutes before it eventually started to flow. I got two of the Posiflow pumps that can lift 1.2m, so that should work OK I hope.

The CAV filter/water trap is next, these are cheap little filters that will keep the nasties out of the Pollak valve. It seems the main cause of failure of the Pollak valve is it jamming due to contamination and the plastic gears stripping. This should solve the problem without creating a fuel delivery problem which a smaller filter might. I bought a box of 10 CAV filters for $30, which is not bad for something I have been running on the Discovery for 2 years without needing to change the filter.

Next in line is the Pollak valve which switches fuel supply between the two tanks. It also switches the return line and the fuel sender unit lines. I may decide to fit another fuel gauge for the second tank, but it would only take a second or two to switch over the valve if I was unsure of how much fuel was in the second tank so I may not.


The second function of the Facet pump is to be able to transfer fuel from one tank to another. I have not shown it on the diagram, but it is a just a valve between the supply line of one tank and the return line of the other. Opening the valve with the pump on will draw fuel from the tank, through the filters and back to the other tank. This should enable us to clean out dirty/watery fuel should we be unlucky enough to get some. I still have to fit these ,just looking for some small valves.

The photo below shows the set-up on the drivers side with showing the CAV filter and the Pollak valve. The mount on the valve was a bit weird, being at a strange angle. I decided to fit a support bracket to hold the fuel line and take all the weight off the Pollack valve. That should help it survive a bit longer.




Other things that have been done is the exhaust system for the Webasto 90ST diesel furnace. I will drill a hole into the side of the bash plate, and direct the hot exhaust inside. This will protect the exhaust from any direct water going up the pipe, and also provide heat to the engine sump as well. Might as well use the waste heat to provide some extra warmth.


I also fitted the stainless steel PTFE hoses that run from the front to the back of the truck for the camper heating system. I sure pays to shop around, I go the 10m of hose for $270, and another $150 for the fittings and crimping. I was quotes $125 per meter to make up the hoses from Pirtek and even more from other places. Because of this I struggle for a week trying to get some solid stainless steel lines bent up and fitted, but it proved to be too difficult. I might have been possible with the camper off the truck, and the cab tilted , but I could not make the pipe fit. I scoured the internet, found a company call Pacific Hoseflex who sell the hose in bulk and asked them for a quote on supplying 10m of the braided hose.

The hose is very strong and very stiff. I had a 50/50 choice between which angle I wanted the hose tails relative to the one in the front to be as once they are crimped they don't move. I got one right, but was out by 180 degrees on the other one. A spare elbow later, and it was all sorted.



I also got the little electric booster pump. If it is marketed by Davies Craig, but it is actually a Bosch pump. it is tiny and doesn't need any brackets as it weighs less than the hose. This is what the heating system looks like now. I have used a special hose supposedly good for everything from oil to transmission fluid to fuel at 300psi , so should last for a while in our heating system.




Finally a last "beauty shot" from this evening.

When does the expedition start?

gawd,, I hope the heater for my van isn't that complicated

Not a bad pic on the phone next to the hot plate either.....