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[geoffr70]

Hello all, after doing quite alot to my 3.0 v6 over last few months. I have noticed that occasionally the brakes don't seem to bite very well.

It's had new discs and pads on the front and new fluid (no air), I tightened up the hand brake shoes and cable yesterday aswell.

I've had a load of vacuum pipes off and replaced some. When I put the plenum back on, I noticed that the brake servo pipe was not as free as it used to be (you couldn't move it round as much). I didn't free it up as it was late and I was tired.

So anyway, very ocassionally when i brake hard, there just doesn't seem to be as much stopping power there. It was quite worrying earlier this morning when I got caught out leaving a roundabout! Just aswell I've got strong thighs!

This happens only rarely though. What would anyone suggest please? Check vac pipes, brake vac pipe and connections in particular? Thanks!

[iainb]

When braking does the pedal sometimes kick back rapidly ?

[geoffr70]

no, it feels entirely normal, just not as much braking force

[Kneepad]

It's had new discs and pads on the front and new fluid (no air), I tightened up the hand brake shoes and cable yesterday aswell.

quote]


You did get all the grease off the discs before fitting ?

[iainb]

It maybe worth check all the vacum pipes again for security.Make sure the nut on the plenum is tight and the booster conection is firm.

[geoffr70]

It's had new discs and pads on the front and new fluid (no air), I tightened up the hand brake shoes and cable yesterday aswell.

quote]


You did get all the grease off the discs before fitting ?

Yes absolutely, I've done a few long drives, and a few 'spirited drives' since changing discs and pads, all ok. It stops brilliantly, apart from this annoying intermittent problem. Thanks Kneepad

[geoffr70]

It maybe worth check all the vacum pipes again for security.Make sure the nut on the plenum is tight and the booster conection is firm.

I'll do this again then! I'll check nut to plenum, but what is the booster connection? I have a crack in the lower divider below the inlet bridge (got a replacement on its way). I think this must be unrelated though! Thanks IainB

[iainb]

The large pipe from the plenum goes to the brake booster (aka brake servo)

[geoffr70]

I've just had it all off and checked the vacuum pipes, in particular the brake servo pipe. There was a small indentation where I had trapped it before with the plenum, I don't think it's pierced though. I'll get a replacement anyway. Also, the end that connects to the brake servo doesn't seem particularly secure. I wiggled it out and it sucked in so there must have been a vacuum in there so that must be ok then? Popped it back in for now.

I've also got a new lower divider on the way as I have a cracked one on atm. Could this be related? My reason in thinking that is when i'm braking I'm not accelerating (obviously), so there will be less of a vacuum, right? But then if the lower divider is not sealing to the head and/or inlet bridge, this could make the vacuum even less in the plenum where the brake vac pipe connects? This would then not provide as much if any, assistance to braking? What does anyone else think?

It can't be the brakes themselves, I think it's got to be the assistance as it ony happens occassionally. Thanks

[cem_devecioglu]

when stopping at the lights try pumping the brakes several times, if it makes big difference there is a problem..

[Abiton]

...My reason in thinking that is when i'm braking I'm not accelerating (obviously), so there will be less of a vacuum, right?...

Least vacuum in the manifold at wide-open throttle, most with closed throttle.