1989 Reliant Robin

While the Robin's lightweight glass-reinforced plastic (GRP) bodywork is entirely immune to rust, the steel box-section perimeter chassis underneath is highly vulnerable to corrosion. Road salt, water spray, and trapped mud in wet UK winters rot the steel outriggers, rear leaf spring mounting brackets, and the central front steering fork headstock. Structural corrosion on pre-galvanised Mk1 frames often requires extensive fabrication or replacement of chassis sections.

Symptoms: Visible crusty rust and flaking metal along outriggers beneath the floor, Cracking around fibreglass body mounting bobbins and floor attachment points...

Est. repair cost: £450–£1,200

Reliant's bespoke 748cc and 848cc all-aluminium overhead valve engines feature wet cylinder liners and an alloy cylinder head. If owners neglect the corrosion-inhibiting coolant mixture or let the radiator silt up, electrolytic corrosion attacks the head face and water jackets. This leads to cylinder head warpage and blown head gaskets, allowing combustion gases into the cooling jacket and coolant into the sump oil.

Symptoms: Milky emulsified oil residue beneath the oil filler cap and on the dipstick, White exhaust steam persisting even after the engine reaches running temperature...

Est. repair cost: £250–£650

The single front wheel configuration places all lateral steering forces and front braking loads through a single front suspension arm, kingpin, and steering headstock. The brass bushes and kingpins require periodic grease gun servicing every 1,000 to 3,000 miles. Neglected lubrication causes rapid ovality wear, inducing severe front-end steering shudder, vague directional stability, and uneven tyre wear.

Symptoms: Excessive play or vagueness around the straight-ahead steering position, Violent front wheel wobble or shimmy over tarmac ripples and cats eyes...

Est. repair cost: £180–£420

The SU HS2 carburettor fitted to 848cc engines develops air leaks past the brass throttle spindle bushes over time. This unmetered air leans out the fuel-air mixture, resulting in hesitation under acceleration, erratic hot idle, and difficult cold starting. Owners often over-enrich the mixture or leave the manual choke partially out to compensate, which fouls spark plugs and washes cylinder bores.

Symptoms: Lumpy or hunting idle speed that changes when pressing the throttle pedal slightly, Stumbling and flat spots when accelerating away from road junctions...

Est. repair cost: £90–£280