Sunday 14 July 2024

Finishing ‘t Kreng’s water pump: take 3

It’s been a while since my last post. Not that I have been idle, but because ‘t Kreng’s cooling system has been putting up quite a fight. I left this job with “only the coolant hoses and the carburettors left to be fitted. Glad I only fitted the coolant hoses and then started filling up the coolant system. Sadly by the time the coolant level reached the infamous connecting tube UKC2538 the coolant started to leak out, not good. Time to call it a day and have a few beers!
After visiting the shed a few days later to collect my trolley jack I found back some motivation to carry on with the job! The sooner ‘t Kreng is back on the road the sooner I can continue work on the ’76 car!


And when I got home the inlet manifold was removed. But on closer inspection I couldn’t find anything wrong, though there had been a little lack of resistance when pushing the manifold onto the connecting tube. Time to order some new O-rings in the correct diameter just to be sure, taking the necessary measurements from the various parts. And more waiting for parts to arrive.
In the end the O-rings arrived after two and a half weeks! And they indeed were slightly larger compared to the ones supplied some time ago from a UK based parts supplier. Time for the second attempt to fit the inlet manifold. This time there was a noticeable increase in resistance while mating the manifold to the connecting tube. But again no success! While pouring coolant into the system through the thermostat cover a leak sprang from the connecting tube as soon as the level got above the top of it. Some expletives were uttered! At least the water pump itself was still leak free.


And time to remove the inlet manifold again. This time the cause for the leak was rather obvious. The upper O-ring had caught the edge of the manifold opening and got partially dislodged. Time for take three. But first I had to order a new manifold gasket as the “old” one got damaged while removing the manifold.


Sadly I was again let down by a supplier or courier. The gasket should have arrived on Saturday morning at the latest. It didn’t. As the car is booked for its biennial MOT this Wednesday I couldn’t wait much longer. Luckily I stumbled upon a long forgotten stock of gasket paper with different thicknesses, hidden in the attic. So I had a go at making my own gasket. Using the old item plus the inlet manifold as templates. Fairly straight forward, but time consuming. And as it was late in the afternoon by now I decided to call it a day. Oh and I forgot the pictures of the finished product.
So this morning I had a fairly early start for my third attempt. I have to admit that I had used some of the time while waiting for parts to arrive to work out a plan to fit the manifold. In the end I decided it would be better to put the connecting tube into the manifold before adding the manifold to the engine, using telephone pliers to keep the tube as low as possible in the manifold while adding the lower part of the tube into the water pump cover.
And with the manifold and home-made gasket roughly in place I could again start fitting the stainless bolts. These were chosen to reduce galvanic corrosion between steel bolts and alloy engine parts.


Everything seemed to go well, but when adding the second to last mounting bolt, it didn’t want to go in properly. I managed to get it in by hand in the end but it felt as if the thread in the head is on the way out. So I was rather careful to (over)tighten it. Next time the manifold comes of said bolt hole will probably need a thread repair.


And with all bolts tightened up it was time for the dreaded final task. Filling up the system with coolant. I again decided to fill it through the thermostat cover. But when the thermostat house was starting to fill up there was the dreaded sound of escaping coolant. Luckily it turned out to be coming from the coolant hose that runs between the thermostat and the radiator. This was still fitted to the radiator, but the other end was resting on the water pump cover. And after cleaning of the coolant I could conclude that the tube seemed to be waterproof. Result!


Left me with the rather relaxing job of refitting all hoses, the carburettors and the strut brace. But not before these were treated to a good clean.


Final job for tomorrow evening will be topping up the coolant level and hopefully a test drive to see if everything still works as it should.



Update 15-07-2024: Tonight I first checked the coolant system for leaks (there were none) and topped up the coolant level. And after expelling any trapped air and checking the fuel lines for leaks under pressure, it was time for the final test, starting the engine. It started promptly after which I let it run till the temperature gauge reached the ¼ mark. And after that there was the much dreaded final inspection for any leaks. So far everything is dry. A test drive is scheduled for tomorrow evening, and MOT on Wednesday. And hopefully time to enjoy the car afterwards!

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