Pug 508 - Automatic Gearbox advice

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Sat 8 Oct 2022 16:50
Pug 508 - Automatic Gearbox advice - Montydom
Hello any automatic gearbox experts. Can someone please explain the connection between brakes and automatic gearboxes. I have a 6 speed Aisin box and I’m getting a jolt. It seems to me that if I have had my foot on the brake whilst say at a junction in D when I take my foot off the brake the car jolts forward. If I have only had my foot lightly on the brake all is ok so it seems related to how firm my foot has been on the brake. It also might do it if the car has been ticking over for a while and going from P to D. Otherwise all is ok. I have read that a faulty abs sensor can cause a jolt but mine seems related the the amount of pressure applied to the brake. So is there a connection between brake pressure and gearbox when stationary. Ta
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Sat 8 Oct 2022 18:58
Pug 508 - Automatic Gearbox advice - elekie&a/c doctor
An abs sensor fault would trigger the warning light , so can’t see it being that . If the problem is worse with more brake pedal force , then I can only think you possibly have a sticking brake calliper/ brake pad .
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Sun 9 Oct 2022 07:07
Pug 508 - Automatic Gearbox advice - Montydom
No the calliper/pistons are ok and changed the pads today.
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Sun 9 Oct 2022 08:53
Pug 508 - Automatic Gearbox advice - DavidGlos
Does it have auto hold? Perhaps only engages with a firmer shove of the brake pedal, but releases with more of a jolt than if you have held the car stationary with gentle brake pressure?

Edited by DavidGlos on 09/10/2022 at 08:54

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Sun 9 Oct 2022 16:42
Pug 508 - Automatic Gearbox advice - Montydom
No that I’m aware of. Light brake pedal all is ok, firm brake pedal I get a jolt when releasing the brake but not always. I read a dirty abs sensor can cause the gearbox to jolt so next step us the clean them. Would like the abs communicated with an auto box. Those gearboxes are known for jolting but there are no issues with gear changes. It just seems to relate to how harm the car is held on the brake pedal.
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Sun 9 Oct 2022 18:22
Pug 508 - Automatic Gearbox advice - elekie&a/c doctor

Modern cars are a network of electronic control modules that "talk "to each other via the can network. So yes, the abs system will be linked to the gearbox and loads of other systems. Cleaning the abs sensors is very unlikely to improve matters, in fact you could do more damage trying to remove them.

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Sun 9 Oct 2022 19:18
Pug 508 - Automatic Gearbox advice - Bolt

No the calliper/pistons are ok and changed the pads today.

that doesn`t mean the pistons- callipers are perfectly ok, pistons can stick in the bores if they are worn, other possible is flexi pipe internal rubber failing causing it to act like one way valve for a split second, just a thought ?

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