Brakes: Reduced braking efficiency

[lynns hubby]

You crack each corner separately. Start at the furthest calliper from the master cylinder (NSR) then OSR, NSF and finally OSF.
before you start bleeding with the pressure bleeder,remove as much fluid as you can from the master cylinder with a syringe or turkey baster and top back up with new fluid so as you don't need to push a reservoir full of old fluid through. Ours is an XC so is high enough of the ground at the front to get to the bleed nipples with out jacking up or removing the front wheels but obviously its easier with the wheels off.

[Bashy]

Originally Posted by lynns hubby

You crack each corner separately. Start at the furthest calliper from the master cylinder (NSR) then OSR, NSF and finally OSF.
before you start bleeding with the pressure bleeder,remove as much fluid as you can from the master cylinder with a syringe or turkey baster and top back up with new fluid so as you don't need to push a reservoir full of old fluid through. Ours is an XC so is high enough of the ground at the front to get to the bleed nipples with out jacking up or removing the front wheels but obviously its easier with the wheels off.

Cheers, appreciate the advice, been many years since I did one

So will this help with the brakes going solid and hardly working?

[lynns hubby]

That sounds more like a servo issue to me.

[Bashy]

God i hope not, this was a reply from AndyV7o

Ok, so, couple of things to say here;
Fluid, change it as said, Dot 4 plus or Dot 5.1 (not dot 5), but go round car twice and ensure you draw about 2 litre through to ensure it is fully flushed.
Second, an ineffective servo gives a hard pedal and ineffective braking, but never know this to be heat related, theres no reason for it to be, unless something in vacuum system is failing when hot, but that would be more engine temp related not brake temp. Thus, its unlikely to be servo.
It sounds like brake pump, Ill come back to that.
Thirdly, pads, what make are they? It sounds like budget pad behaviour. When pads overheat they lose their friction properties meaning you have to stand on the pedal eith little effect, this is what you are having.
Brake pump, if the system has a lot of fluid in there and that fluid expands due to heat, the system pressurises meaning when you apply the brakes theres little travel.
Thus if you have cheap pads and too much fluid, hard pedal, no brakes. This could also indicate a master cylinder issue if the heat is causing something to inhibit the expanded fluid returning to the reservoir.

So, in short, change the fluid for a quality brand dot4+ or dot5.1, and put some Ferodo pads in there (FDB1382) as I know they work very well in the P2 and ferodo pads are VERY fade resistant. Either that or Volvo pads. Dont buy owt from eurocarparts.

Thanks for the info Andy, I will follow it

[davebb]

Hi what size are the front discs , I had this when I had 286mm, I changed to 305mm and had no problem ,
Dave

[Bashy]

Originally Posted by davebb

Hi what size are the front discs , I had this when I had 286mm, I changed to 305mm and had no problem ,
Dave

HI, when I checked with the discs still on, it looks like 305's

[Bashy]

Originally Posted by lynns hubby

You crack each corner separately. Start at the furthest calliper from the master cylinder (NSR) then OSR, NSF and finally OSF.
before you start bleeding with the pressure bleeder,remove as much fluid as you can from the master cylinder with a syringe or turkey baster and top back up with new fluid so as you don't need to push a reservoir full of old fluid through. Ours is an XC so is high enough of the ground at the front to get to the bleed nipples with out jacking up or removing the front wheels but obviously its easier with the wheels off.

Hi, this quote is fron the Haynes manual, I don't get what it means regarding mention the handbrake, also the sequence is different to yours?

Bleeding sequence
11 if the hydraulic system has only been partially disconnected and suitable precautions were taken to minimise fluid loss, it should only be necessary to bleed that part of the system (ie, the primary or secondary
circuit)

12 if the complete system is to be bled, then it should be done in the following sequence:

a) Front left-hand brake
b) Front right-hand brake.
c) Rear brakes (in any order).

[lynns hubby]

The reference to the "Front" handbrake makes no sense to me whatsoever.
I have just changed the fluid on our XC70 and there is definitely only one nipple per calliper.

[Bashy]

Originally Posted by lynns hubby

The reference to the "Front" handbrake makes no sense to me whatsoever.
I have just changed the fluid on our XC70 and there is definitely only one nipple per calliper.

I think I get it now, its meant to be front left hand brake NSF, the hyphen makes it look like they mean front left - (then) hand brake

But the route is different to what you describe, I have just checked Vida and they confirm what Haynes says, so are you sure you've been doing it correctly? see image from Vida.....

[lynns hubby]

Looks like I done them the wrong way round. I don't expect it matters in my case as I was changing the fluid as opposed to bleeding air out of the system.
However, point noted thank you.