Auto Gearbox reluctant to change up
Discussion
Years too late I know but it may help someone else. A common fault with all automatic transmissions (Daf rubber belt jobs excepted) is a clogged filter. What happens is that detritus (posh word for muck) comes off the clutches or brake-bands as they wear. This dirt can clog the ATF filter and reduce the hydraulic pressure that is needed to operate the servos. As most transmissions have what is basically a hydraulic computer to calculate the gear-changes, this is bad news. Standard DIY procedure is (1) Drain ATF. (2) Drop the oil-pan or sump. (3) Clean the oil pan and filter. (4) Reassemble and refill.
ATF should be pink. If it is brown and smells like burnt toast there is a serious and very expensive problem.
Some faults are cheap to repair. For example the venerable and very safe (it has TWO hydraulic pumps) Borg-Warner 35 can suffer from a worn Front Pump Seal. The result is loss of ATF when the transmission is hot after motorway work. A genuine seal only costs a few pounds but the work to replace it is no joke.
The accountants have done away with two-pump autos but IMHO the one-pump autos can be deadly. For example a car that is low on fuel can have its engine quit when descending an escarpment. PAS failure is instant and PAB failure occurs soon after. One then discovers that one needs the weight of an elephant to do the work that the brake servo was doing.
One solution for a death-trap car is to fit a 12v vacuum pump that kicks-in when the vacuum is below par. A modified air-horn compressor might do it. Take care!
ATF should be pink. If it is brown and smells like burnt toast there is a serious and very expensive problem.
Some faults are cheap to repair. For example the venerable and very safe (it has TWO hydraulic pumps) Borg-Warner 35 can suffer from a worn Front Pump Seal. The result is loss of ATF when the transmission is hot after motorway work. A genuine seal only costs a few pounds but the work to replace it is no joke.
The accountants have done away with two-pump autos but IMHO the one-pump autos can be deadly. For example a car that is low on fuel can have its engine quit when descending an escarpment. PAS failure is instant and PAB failure occurs soon after. One then discovers that one needs the weight of an elephant to do the work that the brake servo was doing.
One solution for a death-trap car is to fit a 12v vacuum pump that kicks-in when the vacuum is below par. A modified air-horn compressor might do it. Take care!
Oh I almost forgot. I have read about cars that ran away out of control and killed their owners. When the wrecks were tested, presumably on level ground, no fault could be found with with the braking system. Well I know exactly what causes these runaways What is surprising is that as soon as the car reaches level ground all its vices disappear!
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