Flushed with success
As expected, the TR7 has received most of my attention this month. First task was to thoroughly flush the cooling system and refill with fresh antifreeze. Editor Gary recently covered cooling system flushing in detail, ( CM 210), so I followed his recommended three-stage process – cleaning the insides of radiator, engine and heater. I started by dropping out the old coolant into a drain tray by disconnecting the bottom radiator hose, then flushed the three parts of the system with a hose. Choosing a two-part flushing kit, I added the first bottle to the radiator, topped up with water and, following the instructions, ran the engine for thirty minutes at a fast tickover. This compound should remove scale and corrosion; certainly the filthy state of the water when I drained down again suggests it did the job well.
The system was flushed and filled again with water, then the second, neutralising part of the flushing kit was added. Another fifteen minutes at fast tickover
The water was coming through clear – a
good sign the flush was successful
and this was drained. To enable really thorough flushing I removed the thermostat to flush radiator, engine block and heater matrix in both directions with a garden hose. By now the water was coming through crystal clear – a good sign that the flush had been successful. The thermostat was replaced, along with a new gasket, before the cooling system was filled with a 33 per cent antifreeze solution – strong enough to protect the engine internals from corrosion and to fight the coldest of British winters. TR7s are notorious for airlocking, so I rigged up a funnel and hose to fill via the highest point, on the thermostat housing.
The other main job done on the ‘7 this month also has a seasonal flavour. The smart looking hood seems fairly new, but is not waterproof; the canvas lets water through rapidly in a shower. A few months ago Gez Hughes gave a masterclass on reviving tired hoods ( CM 207). As the TR7 hood looks quite decent, I simply shampooed it to remove any dirt, rather than using a full hood reconditioning kit. After drying out overnight in the garage, I waterproofed the hood using a tip given many years ago by a professional trimmer and hood fitter. He advised that if the hood is clean, spraying with a Scotch Guardtype protective aerosol acts as a water and dirt repellent coating. When thoroughly dry, I masked around the hood and sprayed two coats of the protective aerosol. Although this job required two spray cans, it still works out far less expensive than proprietary hood revival kits. One of the hood’s quarter windows had a small split (only 5-6mm long), so I sealed it by applying a drop of Vinylweld on the inside. Finally, the pivots of the hood frame were lightly oiled. I will report back on how effective my quickie hood improvement turns out through the winter months. A spray of water from the hose ran straight off, so signs are encouraging.
The final job was a matter of safety – replace a fuel hose that looked dangerously stretched. The flexible hose that connects the engine-mounted fuel pump to the metal fuel pipe running under the car from the tank was stretched tight. Engine vibration clearly threatened to break or disconnect the hose, with obvious potential for disaster. With the fuel level low in the tank, the old hose was removed and replaced with a suitable length of new rubber fuel hose. It’s vital to use the correct type of hose as many rubber compounds dissolve in petrol. Proper fuel hose always carries a printed marking along its length, confirming its suitability.
The list of improvement tasks for the TR7 continues…