Austin A70 Hereford 1950-1954 Engine Overhaul Manual | PDF Download

Models covered

• Austin A70 Hereford Saloon
• Austin A70 Hereford Coupé
• Austin A70 Hereford Countryman
• Austin A70 Hereford Pickup

What’s in the manual

Engine specifications and technical data
Bore, stroke and compression ratio, power output and operating speeds. Construction of the block, crankcase, cylinder head and combustion chambers, crankshaft, connecting rods, pistons, camshaft and valve gear. The clearances you’ll be checking against: piston-to-bore, ring end gaps and groove clearances, main and big-end bearings, tappets, plus valve timing settings and camshaft timing marks.

Engine removal and refitting
Taking the engine out on its own or together with the gearbox, disconnecting controls and connections, lifting, mountings, separating engine from gearbox, and refitting and alignment, including centring the clutch.

Complete dismantling and rebuilding
Stripping the cylinder head and checking valve guides, springs and seats. Removing the timing cover, front mounting plate, sump, flywheel and crankshaft. Taking out pistons and connecting rods, measuring bores and piston clearances, and fitting new rings. Inspecting main and big-end bearings and the camshaft and its bearings, checking the timing chain tensioner, and aligning the timing marks to set valve timing. Then the full reassembly sequence.

Servicing with the engine in the car
Tappet clearance adjustment, rocker arm and bush replacement, pushrod removal, cylinder head removal and nut tightening, decarbonising, valve grinding and valve spring replacement, ignition timing, and how to read oil-fouled and fuel-fouled spark plugs.

Cooling system
Water circulation, radiator removal and refitting, thermostat servicing, draining and refilling, fan belt adjustment, frost precautions and overheating causes. The water pump is covered from removal to reassembly, including spindle, bearings, impeller and sealing ring.

Fuel system and Zenith carburettor
Petrol tank removal and gauge sender unit, manifolds, exhaust pipe connections, throttle linkage, choke and starting controls. The Zenith 42 VIS downdraught carburettor is covered in detail: standard settings, starting and slow-running systems, progression, economy device, accelerator pump, jets, emulsion block, float chamber, dismantling, cleaning and adjustment.

Air cleaner and fuel pump
Air cleaner servicing, and the AC-Sphinx mechanical fuel pump: diaphragm, valves and filter, dismantling, inspection, reassembly and adjustment.

Lubrication
Oil circulation, sump draining and refilling, oil capacity, pressure readings and gauge operation. Tecalemit and Micronic oil filter servicing, oil pump removal and servicing, the gauze strainer, relief valve, and lubrication of the rocker shaft, crankshaft, big ends, camshaft and timing chain.

Fault diagnosis and remedies
Loss of power, poor compression, incorrect ignition or valve timing, blocked jets, overheating, high fuel consumption, sticking, leaking and burnt valves, worn rings and grooves, scored bores, weak valve springs, carbon build-up, oil leaks and heavy oil use, low oil pressure, bearing failure, worn crankshaft journals and wrong oil grades.

Borg & Beck clutch
The 8-inch single dry-plate clutch: driven plate, cover, pressure plate and springs, release levers and bearing, operating shaft, and pedal linkage for right- and left-hand-drive cars, early and later types. Free-play and release lever height adjustment, removal, dismantling, wear inspection, reassembly and setting with the assembly tool.