Engine Cooling System Overhaul – Part 2

At the end of my last update – Engine Cooling System Overhaul – Part 1 – you may remember that all my hard work had been thwarted by a tiny little pinhole in the radiator. Finally it is time to address that and finally tick off this part of the restoration as complete.

But first up, I picked up a set of part worn tyres from my local tyre centre, too long has this car been sat still with nothing but rotten rubber the only thing separating the rims from the ground!

It might not have been the most crucial job at this time but easy wins are good for motivation, and to paraphrase my wife – “it makes it look like we have a car on the drive, instead of a rusty old skip”.

Back to the main purpose of this update, a new radiator. A bit of research suggested that Nissens radiators are a good cost effective replacement and are close to OEM quality, at a fraction of the price of a genuine new Mercedes item, so that much was easy.

What was tricky was sourcing a pair of new automatic transmission fluid hoses – these are the two ~6 inch long hoses that connect in to the bottom of the radiator of W123’s with automatic transmission. Searching online for these only brought back results from the USA and although not expensive, shipping costs and delivery time is more than I am used to, but they were necessary so what can you do?

A couple of weeks after ordering a pair of these hoses listed on ebay, I get an update from the seller apologising that they only had one left in stock, despite having long since been notified that they had been dispatched, but it’s OK, they were refunding me half the cost. [Roll eyes]

There is not much I can do with just one hose and I was reluctant to order another from the states with the long shipping time, so back to the search. Anyone looking for parts in the UK will probably have come across the many different yet strangely similar online parts companies, and despite having .co.uk websites they all seem to ship from warehouses in Germany. This is not necessarily a bad thing, my previous parts has come from one of these companies and the service has been fine, with delivery much quicker than from the states at least! The trouble is when searching under my model of vehicle, it seems these hoses do not exist, the same problem that originally set me off looking further afield. So I started looking at older models that used the same M115 engine, looking for the same hoses but this time for a W115 and jackpot. Turns out there must be a error int the database the parts dealers use and these hoses are in fact readily available in Europe.

The image above shows the two new ATF hoses, compared to the one that finally arrived from the USA. They don’t have the additional protection, but neither did the original Mercedes hoses, so that is good enough for me.

With the old radiator out I gave the area a clean and noted a few more areas of rust. Another problem for another day!

Here is the original radiator next to the new one, can you spot the leak?

I had actually attempted a solder repair of the original radiator previously, just as a quick and easy fix. But the aluminium waterways were so brittle that it continued to split and it was quickly obvious that I was wasting my time.

But this earlier removal of the radiator did highlight the fact that the ATF hoses needed replacing, something I may not have known until now and would have thrown another spanner in the works when it came to fitting the new radiator.

The rotating nuts on the original hoses were completely seized and removing meant twisting the hoses to the point that they became damaged, they were never going to be re-usable so cutting them was the easiest way to getting them off.

There we have the new radiator in place and the new ATF hoses reinstated. Then it was time for a brew while I handed the car over to my chief jubilee clip doer-upper for final connection of the water hoses.

And there we have it, job done.

I am pleased to report that finally the overhaul of the coolant system is complete.

While I was at it, I fitted a new fuel hose to the fuel tank outlet and connected up the fuel lines in the engine bay, no more running the engine from a petrol can wedged behind the headlight.

And as if by magic, having a fully functioning coolant system the engine no longer cuts out when it reaches running temperate, fancy that!

Next up I think will be to check over the braking system and then there shouldn’t be much stopping me from getting it back on the road.

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