Peugeot 306 HDI 2.0 2001 - brake pressure

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Fri 7 Jan 2011 19:45
Peugeot 306 HDI 2.0 2001 - brake pressure - Ozone

Amongst many ongoing ECU/Limp mode problems my most concerning is this:

The brakes are often a bit jammed when starting a journey with a little jolt sensed as you move off. As well as this the brake pedal is hard and much less effective for a few minutes and then returns to normal operation. For the first time yesterday this happened in the middle of a journey and caused a little 'moment' as you can imagine.

I have assumed wrongly/correctly that this is not connected with the electronics?

Edited by Ozone on 07/01/2011 at 19:47

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Fri 7 Jan 2011 21:39
Peugeot 306 HDI 2.0 2001 - brake pressure - Peter.N.

It sounds as though the vacuum supply to your servo unit is missing intermittently, I don't know if the pump is belt driven on your car, if so it could be slipping. The brakes sticking may just be due to the discs/drums rusting when its parked.

Edited by Peter.N. on 07/01/2011 at 21:40

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Sat 8 Jan 2011 16:04
Peugeot 306 HDI 2.0 2001 - brake pressure - Ozone
Thank you for your response Peter. Well I've now found out that the supply is not belt driven and also the various possible probs that have caused the 'limp home' ECU mode to initiate have cleared themselves (temporarily I'm sure) and with the removal of the engine warning light the brakes have not since misbehaved. Could the limitations that this mode places on the car inadvertently effect other systems on the car, electronically or mechanically?
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Sat 8 Jan 2011 18:38
Peugeot 306 HDI 2.0 2001 - brake pressure - Peter.N.

I wouldn't think that the brakes would have any connection to the electronics - apart from the ABS, but with modern cars you never know. I certainly don't think an electronic problem would cause the brakes to fail - not exactly fail safe is it?

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Sat 8 Jan 2011 19:19
Peugeot 306 HDI 2.0 2001 - brake pressure - Ozone
Well I guess I'll wait to see whether we have a brake issue before the return of the em light or it returns without the brake issue. Watch this space and thanks again.
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Sun 9 Jan 2011 12:37
Peugeot 306 HDI 2.0 2001 - brake pressure - dieselnut

If it is similar to VW diesels, they use the vacuum to control EGR valve & turbo, so that would explain why loss of brake assistance coincides with limp mode.

You will need to check the vacuum pump & the associated vacuum pipes.

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