alternator brushes

[johnbirchjar]

Hi guys, this has nothing to do with rotarys,but, can anyone enlighten me as to what sort of milage the average family car will do befor the alternator brushes need re-newing? I did the ones on a Cavalier that I owned getting towards the 100,000 miles mark,I have contacted several "auto electricians" but they were unwilling to commite themselves,(surprise, surprise)regards,J.B.

[rustynuts]

The alternator on my Volvo S80 was still going fine without being touched at 240,000 miles. My current car has done 110,000 and it doesn't look like the alternator has been touched.

[andy588tt]

Hi Guy'sAlternator brushes? how long is a piece of string It depends on the condition of the battery and the terminals and if a load has been on the charging circuit like "if you drive with FULL head light on" and mostly night time driving.What would destroy the Alternator brushes is a dirty commutator, "This is what the brushes touch as they go round". each brass strip gets filled with carbon and shorts out, The battery can in time go flat with this short in the alternator .When a new vehicle car is serviced from the dealer up to 60,000 miles the adjusting of the fan belt was done buy the book but if done at Home?, and to much extra pressure is but on the fan belt the tension on the front bearing would shorten the life of the front bearing and miss align the whole shaft with the bush at the back of the alternator and the brushes would not fit squarely on the commutator the whole thing would charge but wear out very quickly.Modern Japanese Alternators are very good and the brushes last the life time of the unit and car!! if fan belt is adjusted properly. Ride SafeAndy

[Richard Negus]

The last four cars, all Cavaliers/Vectras had the original alternators when sold. All working as normal.1.6 Cav. 127,000 ; no problems1.8 Cav. 187,000 ; heater hose burst2.5 Cav, 247,000 ; clutch release bearing grumble2.5 Vec. 223,000 ; leak from power steering, major dismantling to fixI suspect alternators are one of the more reliable components of a vehicle.

[johnbirchjar]

Thanks guys, I will leave well alone,and follow the old maxim,"If it ai'nt broke, don't fix it".regards,J.B.