Use Right Method to Slow Car on Hill

Times Staff Writer

Question: I just purchased a new Buick, and the dealer suggested that I use the automatic-transmission low gear to help slow down the car when I am going down hills. I live in a hilly area and am always using my brakes. But a friend said I will wear out my transmission and that brakes are cheaper than a transmission. Is he right?

Answer: The use of an automatic transmission to slow down the car makes sense only under certain circumstances. The reason you want to use the transmission instead of the brakes is that long and continuous pressure on the brakes while going down a hill tends to get the brakes very hot and can significantly reduce their effectiveness while they are hot.

If you are talking about only moderate hills in city driving, it does not make sense you use the transmission to slow down the car. You do cause moderate amounts of additional wear on an automatic transmission when you downshift to slow down the car. On short hills, the brakes will not get very hot.

The time when you should use the transmission is on very long mountain grades, where you would be going downhill for miles. In that case, you may want to keep the transmission in second gear and use additional braking as needed.

Q: I own a 1976 Ford Maverick with a six-cylinder engine that has 135,000 miles on it. At speeds of 50 miles per hour or more, the speedometer needle fluctuates erratically. This is my first car and I would like to know what is wrong.--T.D.R.

A: Your problem is very easy to fix. The speedometer cable, which runs from the transmission to the back of the speedometer display, has run out of lubrication, and the cable is rubbing against the cable housing.

On older cars, you can usually reach up behind the dashboard and unscrew the cable at its entry into the rear of the speedometer. You want to be sure you unscrew the nut, and do not try to twist the cable.

Once the cable housing is free of the speedometer, you can pull the cable out of the housing and service it. You should clean the cable with some solvent and then put a coat of grease on the cable. You then insert the cable into the housing, and screw it back onto the speedometer display.

Q: I am told that most front-wheel-drive cars have the poor feature of dripping oil for days after an oil change due to the way the oil filter is positioned on the engine. When changing the filter, the oil drains on the framework and then continues to drip.--K.F.R.

A: The problem you describe is not limited to front-wheel-drive cars. When auto manufacturers design an engine, the location of an oil filter is pretty low down on the list of priorities for the engine.

A lot of cars have oil filters that are positioned in such a way that they are bound to spill a large amount of oil when they are removed. If the oil drops onto the frame, it will drip for days. It's almost impossible to avoid.

The situation is getting worse, not so much because of front-wheel drive. Engine compartments are packed full of emission-control and power-assist equipment these days. Even the old compact cars in the 1960s had plenty of extra room inside the engine compartments.

As a result, the oil filter ends up wherever there is room for it. Sometimes, they are upside down or sideways, and before you can unscrew it, they have made a mess. But car makers know that practically nobody buys a car principally because it has a conveniently placed oil filter.

Q: I have a 1976 Chevrolet Vega that is losing coolant. We keep adding water, but it keeps disappearing, with no sign of a leak. What could be causing this?--M.S.

A: You should first make sure that it's not leaking by having a mechanic attach a pressure-testing device to the radiator. He will pump about 15 pounds of pressure into the cooling system and watch to see if the pressure drops off rapidly.

If it is losing pressure but not leaking outside the engine, you could have a broken head gasket, which means the coolant is being drawn into the combustion chamber and burned with the gasoline. The mechanic can find out where the gasket is broken by removing the spark plugs and seeing which cylinder is getting water in it. Then you'll have to have a new head gasket installed.

Ralph Vartabedian cannot answer mail personally but will respond in this column to automotive questions of general interest. Do not telephone. Write to Your Wheels, You section, The Times, Times Mirror Square, Los Angeles 90053.

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