Monday, 2 September 2013

10CR Preparations last part ... hopefully

(Or how the DHC is trying desperately to stay out of the event ...)
A few weeks ago the car left me stranded on the hard shoulder of the motorway, with what turned out to be water in the tank. After draining the tank completely and fitting a new tank sender I thought it a good idea to check the half shaft bearings. One clearly was on the way out, so that had to be addressed. My initial plan was to remove the original half shafts and replace them with a second hand pair that I have lying around. So I got the tools out again and started with removing the half shafts from the back axle, which turned out to be pretty straightforward as ever;
  1. Remove the brake drum;
  2. Undo the 4 nuts/bolts that hold the half shaft in place;
  3. Leave two bolts in place to keep the back plate in the correct location;
  4. Re-fit drums the wrong way round and tap them with a rubber mallet until the shaft comes out;
  5. Use a slide hammer to remove the outer bearing race from the back axle ...

Sadly on closer inspection, and after trial fitting one of the spare half shafts, it became clear that these were no better compared to the original ones. This left me with the most labour intensive but also by far the best solution for the problem, fitting new bearings to the original half shafts. As there have been some horror stories on bad replacement bearing kits on various forums I made sure to check all the original parts dimensions, against the various parts in the kit ...

But it turned out that all the parts were fine, so time to remove the old parts. Here an angle grinder to weaken the retaining collar and a hydraulic press came in very handy. The last piece of equipment was also used to press the new parts on to the shafts. But first I had the rather simple but oh so messy and time consuming job of packing the bearings with grease. But eventually I was satisfied with them, and all the parts could be fitted to the half shafts.

After which these in turn could be refitted to the back axle and I am glad to say that the end float on both sides was well within tolerance.

With the half shafts sorted I switched my attention to the remainder of the fuel system, the fuel lines and the carburettors. Again a rather straightforward but also rather time consuming job. Removing and/or disconnecting everything, cleaning it thoroughly and putting everything back together. Also used the opportunity to polish the inside of the dashpots, and the rims of the pistons (years ago I found out that this helped with the pistons action and would smoothen the engines behaviour slightly, and all little bits count :-). And while tinkering with the carburettors I found "proof' that a fair amount of water had indeed entered them, as one of the  needle guides already had some surface rust on it. But with everything cleaned, reassembled and reconnected (including a new inline fuel filter) it was time for the test. And with 15 litres of fuel in the tank I found out I again have a working fuel gauge, and after cranking the engine over a few times to get some fuel back in the float chambers, the engine fired up without any problems.

But by that time I had noticed a fluid spill underneath the car, which needed a closer look. As it was right underneath the radiator, didn't smell of petrol, and it hadn't been raining for a while, it was pretty safe to say it was coolant. An inspection of all three hose connections didn't reveal any leaks, but when I checked underneath the car with a small torch I noticed a small drop of coolant coming from the left-hand lower mounting pin, not good. And as I don't fancy driving across half of Europe with a suspect radiator, I decided to take it to a local radiator repairer and have it tested. It indeed was leaking in two spots, both at the top and one on each side of the core, where the radiator tubes pass through the end plate and enter the side tanks. The initial verdict was a manufacturing fault. Needles to say I wasn't pleased with that, especially bearing in mind that I fitted that radiator new just over three years ago. (I have contacted the supplier and sent an e-mail which they forwarded to their manufacturer Serck Motorsport, but so far no reply, so to be continued).

Sadly enough the radiator repairer wasn't able to help either as they don't work on alloy radiators. But he pointed me to another small local firm who might be able to repair it. And he agreed to open up for me the next Saturday morning to see if they could help. His verdict also was a manufacturing fault, and he wasn't positive on repairing the leaks. According to him that wouldn't be a long term solution, if possible at all. His opinion was that the used core is incorrect, they used a "standard" alloy radiator core designed for plastic side tanks instead of welded alloy tanks. This explains why the end plates at both sides of the core are flat. As a result of which the welding for the side tanks had to be done to close to the core tubes, weakening the pressed joints between the end plate and the tubes. The same applies for the two large hose connectors. He predicts that when the radiator is repaired it will sooner or later develop another leak somewhere else. The fact that we found the radiator to be slightly warped certainly won't help with longevity. As time till the start of the 10CR was getting rapidly shorter, I decided to order a new radiator, which he promised would be ready for collection on the Monday before the 10CR at the latest.

So to kill the time while waiting for the new radiator to be ready I fitted the original radiator of the car so I could drive her a bit and see if everything works. So of for a short trip across the border into Germany for some decent 102 RON octane fuel and a little test drive. After filling her up I noticed that fuel gauge would move up and down rather violently under acceleration, braking or going over bumps. Initial thoughts were a loose connector, but over the next 40 to 50 kilometres the movement became less and less till it stopped completely. Might have to do with the NOS tank sender I fitted recently needing some time and fuel saturation to settle down?  And while driving (well actually while waiting for traffic lights) I found out that the carburettors needed some tweaking, because when on temperature the engine would idle @ 1500 rpm. Which was an easy fix, also used the opportunity to balance the carburettors. And last but not least I flushed the hydraulics of the brakes and the clutch. Especially the clutch fluid was rather murky to say the least. It also cured a slight spongy feel of the brakes.

And today I picked up the new radiator ...

It not only looks the part, but it is also about an inch wider compared to the original one. Not really necessary from a cooling point of view, but the space was available, it didn't add to the price and it adds a bit of extra capacity to the coolant system just in case ...

And returning home from a short 150 kilometre test drive revealed it works perfectly, with the temperature staying on the lower part of the scale of the temperature gauge. Only problem was the left hand side hose was leaking a bit when the system was pressurizing after I switched off the engine. Turned out that the hose clip had come loose slightly causing a small leak but that was dealt with easily. Remains fitting the steel wheels and the badges, and load up the car for our departure on the Wednesday morning.
Oh ... and make a new right hand rear mud flap as I managed to tear it of while reversing into a parking space.

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