Daimler water pump and 'bellows' type thermostat opening at 77°C.
Bottom radiator hoses are 2 of John Bull part #220.
Lubricate water pump bearing every 3,000 miles (eg.) with Marfak 2 H.D.
At intervals, check thermostat is operating correctly (see notes below).
Aside from leaking gaskets, the most common problem is thermostat failure. Ensure use of anti-freeze in the cooling system and occasionally flush out to prevent rust particles blocking the thermostat or radiator.
The bellows-type thermostat will fail in the open position (the bellows corrodes and perforates, losing the vacuum), thus preventing the system overheating, whereas modern replacements may fail in the closed position, leading to a more serious failure condition.
The thermostat rests in the housing and can be removed by undoing the 2 vertical screws in the thermostat housing and bending the upper hose pipe slightly to clear.
To remove the water pump, undo the 4 lower screws/bolts and disconnect/remove the hosing and fan belt. The upper 4 screws/bolts hold the back plate to the water pump and need not be removed.
To remove the impeller (from the pump) requires an extractor. This can be made from a thick (1/2") steel plate with an M12 or 1/2" BSF screw tapped through the middle and 2 clearance holes drilled either side (to match the 2 tapped holes on the impeller).
Screw 2 screws through the clearance holes into the tapped holes until they bottom. Then screw the larger screw into the center hole until it hits the center of the impeller shaft. Keep screwing it in and it will force the impeller shaft through the impeller, until the impeller comes off.
On no account attempt to use a hub extractor or similar claw device since the force from the hooks on the
outside of the impeller will break it.
An AC Delco type TC 'bellows' thermostat should be suitable, although the diameter is slightly oversize at 2.13" and may need to be filed to fit. Types TC-4, or TC-9, (both 77°C) might be considered. Type EF-3 has also been used successfully.
The large size of the thermostat means that there are many possible substitutes, provided the flange diameter (2.074") will fit. The constraints are the depth of the housing and the height of the housing cover (see measurements in diagrams below).
When the thermostat is closed and the engine is at a fast idle, the engine should reach running temperature within three or four minutes with a heater hose closed. It would take longer in the winter, or with the heater hoses open. Watching the temperature gauge will show when the thermostat opens - initially the temperature will rise steadily, when the thermostat opens the temperature dips, and on further running, the temperature will continue to climb, until normal running temperature is reached.
If replacing the thermostat, note that it should not be replaced by one of a higher opening temperature. A lower opening temperature will only affect fuel consumption. It is recommended that any replacement be of the bellows-type if possible, since these fail in an open position and thus avoid boiling the engine coolant.
To test the thermostat or temperature gauge, simply place the thermostat, or the bulb end of the temperature gauge, in a pan of water and bring to the boil. The thermostat will begin to open approx. 5°C lower than marked (since a pressurised cooling system boils at a higher temperature), likewise the gauge will measure approx. 10°F lower than marked.
A thermostat, believed to be original, was found to be marked only with '43452'.
The water pump bearings may be replaced by the SKF part #402703 (outer) and part #G-8016 (inner).
Note that the original temperature sender is attached to the gauge by a length of thin copper tubing, held by aluminum 'clips' across the top of the manifold. This tubing must not be cut, bent or damaged, but any surplus should be rolled into a 2-3" coil, which allows for engine movement without breakage.
The (John Bull) bottom radiator hoses were fitted to many Daimler and Lanchesters from 1945-1951, however steam hose (1.1/2" bore x 2.3/4" long) is often easier to fit and longer lasting.
All images are scanned from originals, wherever possible, at 100dpi (unless otherwise noted) and must be scaled when printed to preserve the original size (eg. scale up by 3 times for a 300dpi printer).
Note, however, that due to slight scaling inaccuracies during both the scanning and inevitably the printing, these images should be taken as an approximation for reference only.
In addition, drawings, measurements and notes of materials used are intended as a guide and aid to the restorer, and not necessarily a definitive, or even guaranteed correct, reference.
This bulkhead grommet for a 1" hole is probably a damaged grommet for the temperature gauge wire (slightly O/S of the engine).
Screwed to the O/S of the engine, 2 of these aluminum 'clips' guide the wire for the temperature gauge along the length of the engine.
Constructed from a single, folded, rounded-edged strip of aluminum, the image shows the clip springing forward slightly (the clip was not flattened), thus the length of material needed is twice that shown in the image.
Details of a suggested water pump insert, to enable an alternative water pump seal to be used.
The alternative seal is a John Crane part #0158/6J/N/411B.
Sketch of the thermostat, which may be a Smiths part #43452/5 78°C 172°F.
The face is stamped X43452—3900—Pat No 42193.
Bottom radiator hoses (2 of).
None yet.