im pretty sure ive been done

[Darlo 1]

Check your front flexi pipes, they start to split at that mileage, had one go on me a few months ago, luckily i was bleeding them when it went pop, cheap enough to replace from the likes of eurocarparts.

[V40IRL]

Ok so i was at the breaks today, its been a horrible day here so working in between showers. I scoped out the flexi lines best i could and they seem to be all ok. I had the two front calipers off and pistons are free, had the back two off same story there free too... I didnt bother bleeding because the pedal is hard rather than soft and the pressure in the pedal never changes its always just like a normal break pedal, have breaking power until i want more breaking power and push harder but is very difficult to get the car to slow down quickly without putting massive amounts of pressure but normal pressure on the pedal and the car slows down like any other until you want it to slow more but nearly put your foot through the firewall trying to get it to stop. So anyway started thinking vaccum so followed the pipe from the servo back to what im assuming is the vaccum pump on the side of the head (battery side) took that off while the engine was running and put my finger over it it did suck but id imagine it would more? put that back on and took off where it meets the servo and that sucked my finger a bit more but i could leave my finger on it being sucked without having to take it away straight away in fear... Does anyone have any ideas (well more ideas, thanks again) how much sucky pressure should be in those pipes. Like i noticed theres a hell of a lot of pipes working off that one vaccum, i think one leads the turbo wastegate but not sure. I also did the foot on brake and turn on the engine test and my foot did go down but not very quickly so im shtumped

[V40IRL]

Excuse the pro job haha
The yellow circles are where i tried for suction- also is that the vaccum pump?
And what do the things to i have circled green and red?

[IMG][/IMG]

[bobthecabbage]

Apparently the bit in the green circle can leak between the black plastic and the white plastic. Some silicone or instant gasket round there would sort it.

Your brakes sound normal to me. Mine are also crap like that.

If your rear callipers are crusty old original ones it may be worth getting a set of service exchange ones from a motor factor.

My brakes were inconsistent and terrible which turned out to be at least one corner contaminated with grease and a rear calliper sticking.

[V40IRL]

Originally Posted by bobthecabbage

Apparently the bit in the green circle can leak between the black plastic and the white plastic. Some silicone or instant gasket round there would sort it.

Your brakes sound normal to me. Mine are also crap like that.

If your rear callipers are crusty old original ones it may be worth getting a set of service exchange ones from a motor factor.

My brakes were inconsistent and terrible which turned out to be at least one corner contaminated with grease and a rear calliper sticking.

Ill have a feel around that black cylnder yolk and see if its drawing air man thanks, but do you know how strong the suction should be anyway? And when you say contaminted, how do you mean?

[kieran40]

The red one is youre n75 valve but if youre turbo is boosting and operating normally it's no problems there

I wondered myself what that canister thing Is circled in green actually does anybody know.

[V40IRL]

Another lad reckons the vacuum is ok so would it be the servo? Are they a problem on these cars i would have thought thats a bit rare

[bobthecabbage]

The thing circled in green is the vacuum reservoir for the stop valve which obviously requires a vacuum after the engine has stopped and the pump is no longer providing any.
Should operate the valve for about 4 seconds after ignition switch off.

I believe it has a non return valve in it as well so it doesn't lose vacuum back to the system.

You won't notice it drawing in any air from my experience. I taped mine up and in my imagination at least, the brakes did seem slightly better. The tape has fallen off now though.

Don't know what the vacuum should be but this says at least 0.5 bar -ve pressure.

http://europe.delphi-dso.com/downloa...0PROCEDURE.pdf

When I say contaminated I mean the brake pads had grease on them. When the garage put the pads in they slopped grease where the pads slide as they wear. As the discs weren't fixed in place they must have moved and picked up some grease and transferred it to the pads. When everything gets hot the grease soaks into the pad and that is the end of that. Every time you brake the grease melts and lubricates the pads.

This gives very inconsistent braking with nothing happening and then the brakes grabbing when you've nearly stopped.

I diagnosed the worst affected wheel by testing the temperature on each wheel after a drive. First off check the temp of the wheel, then the hub and then the disc but bear in mind if you do any harsh braking you will burn your fingers. It helps to lick them first (your fingers) as if it sizzles then its too hot to touch!

You could get one of those non contact thermometers which would be more accurate and safer.

The roller brake tester at your local garage is a waste of time. My car was thoroughly tested by the garage when I complained and they found no fault.
Yet with 5 people on board I could barely stop going down a reasonably steep hill and I'd get the ABS kicking on the rear wheels on a wet road and not be able to stop.

It my case one front disc used to be notably cooler than the other and the rears were always to hot to touch.

The rear brakes are biased to do most of the work and the fronts only get full pressure when the rears start to slip. So the rears need to be in good condition to get an effective stop.

You may notice if you brake suddenly the car stops better than if you brake gradually. I guess this is due to provoking the rears into skidding which then allows the fronts to get full pressure (and maybe the abs to kick in).

[v40alex]

Did you check the slider pins on the top of the caliper? It's not uncommon for those to get rusted/gunked up. You need to extract the whole pin and check for easy movement, give them a light go over with wet and dry if they are rusty, clean out the old gunk with rolled up newspaper, reassemble with lots of rubber grease.

[V40IRL]

Thanks for the write up Bob! Very helpful
Ok so ive done something right i think. The brakes are really starting to pull the car.. And also im feeling the abs hop off my foot a hell of a lot more than it use to when i slam the brakes. Alex i took off the calipers and did the sliding pins like you said, they were all free and didnt feel gritty or anthing sliding them in and out. So all Ive basically done is on every caliper got a bit of wd40 into pistions and pushed them in and out, i also filed down slighty where the pads seat and gave them a touch of copper g also none of the pads had it on them so they all got coppered up. I really feel like the car is slowing down better (this could be placebo) but as i said the abs is kicking in real good now.
Ordered new driver window switch off antz so hopefully ill have the windows working soon