Spot the grot
… what to fix, what to replace
Oily bits
Until 1978 all Princesses came with a 1.8-litre B-series engine or a 2.2-litre E-series straight-six. The B-series gave way to an O-series powerplant in 1978 in 1698cc or 1994cc forms; all Ambassadors were fitted with a 1.7 or 2.0-litre O-series unit.
An oil and filter change every year or 6000 miles keeps each engine in rude health; use 20w50 oil. The cooling system can struggle to cope so it’s worth fitting a second electric fan to the radiator; Ambassador automatics got one as standard. The straight-six engine is prone to overheating as it has siamesed bores and generates more heat than the four-pot units, plus there’s less ventilation in the engine bay. If it gets really hot a hose will probably blow rather than a head gasket.
The 1800 engine is the most reliable of the lot and the one with the best parts availability. It’s the same as the unit in the MGB, but in the Princess it’s fitted transversely and with front-wheel drive. Parts are generally available for the O-series powerplant; if you encounter a tired engine you’re better off rebuilding it, as everything is available.
There’s a steel pipe on the four-cylinder engines which goes from the bottom of the radiator to the water pump. It rusts through and new ones have to be fabricated. On the O-series the thermostat fuses into its housing which then breaks.
Top-spec Ambassadors were fitted with twin SU carburettors with an automatic choke. The bi-metallic strip that controls everything tends to fail, which is why many of these twin-carb systems have been replaced by a single carburettor, operated via a manual choke.
On O-series cars the fuel pump is inside the petrol tank (B- and E-series engines have a mechanical pump), which creates access problems. Your best bet is to bypass the original unit and fit a secondary pump outside the tank.
All Wedges came with a four-speed manual gearbox or a Borg Warner Type 35 auto. The former is notchy and it’s difficult to get first gear when cold; the master or slave cylinder may be worn. Gearboxes and diffs are tough, with the linkages unlikely to give problems, while clutches are strong and readily available. The Type 35’s casing is unique to the Wedge. ATF must be Dexron-free.
These cars wallow in bends but the trade-off is fabulous comfort on the straights. It’s all down to the Hydragas suspension which works brilliantly and isn’t inherently unreliable. If everything is working properly you should be able to get four fingers between each tyre and wheelarch. If the car is lop-sided or sitting low generally, the system is down on pressure. It’s possible to fix this with the right tools; the fluid should be replaced every five years because after this point the corrosion inhibitor loses its effectiveness.
The displacers can be overhauled for about £100 apiece; it’ll transform the ride and handling, Princess and Ambassador displacers are interchangeable and with the correct piston fitted, Maxi displacers will also fit.
The front displacers go first, especially where the six-cylinder models are concerned because of the weight of the engine. Power steering was standard on six-cylinder cars, the HLS and the Vanden Plas; it was optional on all others. Steering racks are durable but unassisted racks wear, although these can be refurbished cheaply.
‘The tyres are part of the suspension – 27psi and 24psi front and rear’
Any car with its original suspension bushes will have very vague handling; it was never pin-sharp anyway. Focus on the front bushes as they’re the ones that have the hardest time. Also ensure the rubber rebound straps for the rear suspension are intact, because if these have failed the car will dive under braking.
The tyres were designed to be part of the suspension, so they need to be kept at the correct pressures: 27psi at the front and 24psi at the rear.
The brakes are well up to the task; up front are solid discs with four-pot calipers while at the back there are drums. Ambassador (5.5J) and Princess (4.5J) wheels are interchangeable; from November 1980 alloys were an option on the Princess, standard on the Ambassador and Vanden Plas.
Trim and electrics
None of the interior trim is durable; the toughest is the vinyl of earlier base and HL models, or the velour of the HLS. The cloth fitted to the later HL ages worst and the cloth headlining on the Ambassador Vanden Plas tends to sag. The other models tend to give no problems although HLS cloth headlinings can sag in cold weather. The electrics are generally reliable but the Princess was fitted with continental fuses which can be problematic; turning them every so often keeps things working. Corroded connections are common at the headlights. The Ambassador got a different fusebox which is more reliable; any problems can usually be traced to poor earths or dodgy connections.