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Mk I Dennis Dart

Are you running a Mk I Dennis Dart?
some advise from a member
Known Weaknesses/Areas to Focus Upon

1) Some vehicles experience fuel trouble, which is not a surprise as this engine is know for fuel faults. The rotary pump is poor but if the vehicle daily mileage is low you should be able to keep reliability high by draining the sediment bowl on a regular basis (usually mounted on NSR of the chassis), this will help stop contamination to the lift pump and fuel pump. Also, try not to run low on fuel as this will pick up all of the debris from inside the steel tank.

2) The brakes on the Dart were never a great design and require regular adjustment and annual greasing of the actuators. The first signs of maladjustment is when the front brakes start to pull and the rear brakes can partially seize if not worked hard which then require a full strip down. To keep this at bay its worth driving the bus with the retarder switched off every now and again, its the big red pull switch on the dashboard. This will help the actuators to adjust the brakes and as well as reducing the risk of seizing also balances the brake shoes so that the leading shoe does not wear out to quickly.

3) The retarder itself tended to be unreliable so its worth asking a garage or electrician to check the contacts for the Telma. The contact box is located under the floor near the rear axle and its worth whipping the cover off and checking that all 3 phases are in good condition and not burnt or corroded. If the retarder is not working properly the brakes will wear out very quickly. Also worth noting is the often forgotten grease nipple on the propshaft inside the Telma stator, its awkward to get to and many forget that its there resulting in the propshaft drying out and in rare cases can cause the shaft to fail causing significant damage to the underside of the bus (£thousands of damage).

4) The leaf springs are fairly robust but the rubber slippers can fail. Keep this at bay by keeping on top of the shock absorber bushes which are of poor design but are really cheap and easy to replace. The mountings for the rear slippers on the rear axle can also crack, so keeping the vehicle bushed properly should stop this from happening.

5) The gearbox can be troublesome as its primary design was for a pickup truck so its worked hard on a bus. By keeping fresh oil and filters (both external spin on filter AND the sump filter) in it there shouldn't be any problems. If the gears start to slip I would recommend replacing the ATF fluid and using mineral engine oil...sounds crazy I know but it works and you can get anything up to another 5,000miles life out of it!

6) Finally keep the grease nipples greased. Key areas are the kingpins, the propshaft (see above) and the idler gear for the fan belts (which have a tendency to fall off if not greased).


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