Roller blind fix

We fixed a blind the other day! I always wondered if it was doable like this, and if you are careful, it can be done.

When you squeeze the button, the blind should disengage and be moveable up or down. But sometimes, with old age or abuse, this doesn't happen. The tiny pip of plastic that connects the buttons to the sliders has broken off.

If you very carefully drill a small hole, at a slight angle, you can put a small screw in there (see photos) which remakes the connection.

Ok it's not pretty, but it's cheaper than replacement parts - if you could even find them.

Musings on the 410D cooling system

The fan is on a viscous coupling. You can see the vanes in the middle. The vanes sense the temp of the air coming through the rad. As the engine works hard, the coolant temp rises, and so does the temp of the air flowing through the rad. The vanes on the fan sense this, and at a given point the fluid in the vanes expands and engages the fan, which until then had been turning freely. It is arranged this way for fuel economy - you lose a few horsepower when the fan kicks in.

The good news is that if you can feel the fan kicking in and out, then at least it's working. The viscous coupled fan doesn't last forever and many old vans have worn out fans but don't know it. In a cool country like the UK you may never notice - then you go to Europe in a heatwave and climb up the alps ... and overheat. The Merc cooling system is designed for all climates and has a lot of spare capacity.

The other issue is the state of your rad. Again, they don't last for ever, and get clogged up with road dirt, and the vanes get damaged by stones etc. The vanes on the Merc rad are quite close together, so tend to easily get clogged. I fitted a new rad last year and it was interesting to see that there was more space between the vanes on the new rad. If you have a dirty rad, then it's efficiency is reduced, and so the temperature will climb quicker, cutting in the fan. It's a positive feedback loop - and each component of the system needs to be in good condition. So inspect your rad, and have it blown out with a high pressure airline from back to front. If a lot of crud comes out, then that's good!

The way to cut down the noise is by insulation. Most classic Hymers need the dashboard sorting out after 20 odd years - it's a common thing. If you can see the windscreen move slightly in relation to the dash when the van rocks from side to side, then it needs doing. There have been plenty of articles about this. When doing this job, it pays to have the new dash well insulated - thick soundproofing on the underside, and good carpet on top. I also have an extra jacket on the inside engine cover. I did mine 2 years ago, and am very pleased with the results. I reckon my van now drives as quietly as practicably possible.

Musings on the Merc 410D suspension and springs

The Classic Hymer 6 and 700s are on the Merc 410D commercial chassis. It's a good solid platform. But in commercial use - either van or flatbed, it would be lightly loaded when empty of goods, fully loaded (up to 4.6 tons!) when full. Most of the time it would be between the two. But in a motorhome configuration, the caravan body is load, so it comes out of the factory well over half fully loaded, and by the time it is full of people and all their gear it is usually over 4 tons. As a result, in my opinion, the duty cycle of the springs, and in particular the rear springs, is higher than in general commercial use. So they wear out quicker. I have had 2 S700s over 18 years, and my last van I hammered all over the place, clocking up 350,000k on some tough tough roads in Morocco etc. I broke rear leaf springs on 2 occasions, and for most of it's later life suffered from saggy bottom. So it is my opinion now, that after 25ish years it is no surprise than on many vans, depending on use of course, end up with worn springs. So there is a fair case to be made that new springs are a decent investment - certainly on the rear. I think that a 25 yr old van on original springs and shocks is now a completely different driving experience compared with when it left the factory. The problem is that we tend to drive our vans sedately - we don't push them hard, so we don't really notice. I believe that new shocks and springs would transform any old 410 based van dramatically.

It also pays to inspect your springs carefully - you may have a broken leaf, or the U bolt retainers can be broken, plus the springs front and back are mounted to the hangers with heavy duty rubber bushes, which wear out over the years. All these things are easy fixes. I had a new single leaf custom made and fitted in Turkey a few years ago. It took 2 hours and cost £75! I replaced the bushes on my old van and was amazed at the difference.

As for air suspension - Well when I got my second van 3 years ago, I decided to go to town on it, no expense spared. Top of my list was air suspension. It's hard to find the bits nowadays - there are very few left in stock anywhere. It's not the bags, it's the metalwork that goes with them - it's quite a complex fitting on the rear axle of the 410. In the end I ended up having VB air suspension fitted by Conrad Anderson in Birmingham. They told me that I was lucky to find a set still in stock in Holland. It wasn't cheap! Overall I have been pleased with them. But I can't help but think it would have been cheaper to just have had new springs fitted. And shocks. Many vans are still on original shocks - and they are also getting hard to find.

All these experiences, and those of others over the years have led me to conclude that I would rather spend money on new springs (and maybe shocks) than on air suspension. But that is my personal opinion.

As an interesting side story ... last year I bought a 670 in Germany and imported it over here. On the drive back I was amazed at the difference compared with my 700. It handled like a saloon car! On closer inspection I found that it had been fitted with Koni shocks, and the tyres were 205R14 as opposed to the usual 185R14s. The springs looked good - it was quite a low mileage van, obviously well looked after. To me, this was proof that these vans can handle well in old age, if you are willing to put in the effort.

Contacts - As well as Conrad Anderson (they are not cheap!) I have heard that the guy at Marcle Leisure is an authority on air suspension. Also Goldschmitt the German company, but I know nothing about them. For springs, new Merc springs are out of the question - they cost telephone numbers! Midland Road Springs, Jones Springs and Rossendale Springs all have a good reputation. There is also a company in Cheshire that does coil spring assisters for motorhomes, but I can't see the point in assisting tired leaf springs with coils.

Tyre pressures are also important. You need the rears pumped up to the max - 65psi. Personally I run my fronts at 50psi, which is below the recommended.