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matthewwoodward
Friday 29th October 2010, 00:32
Hi Guys,
I have replaced all my discs and pads all round and the fluid and bled the system.
I have a problem in that if I press the pedal it doesnt brake hard, BUT
if I press it then release and then instantly press again, so pump it, the brakes are a lot sharper.
Surely I should need to do this?
Any ideas?
Matt

The Flying Moose
Friday 29th October 2010, 00:46
It sounds to me like you have a faulty master and or slave cylinder. Its quite a common thing. Saw it on a 2.5 Auto V70 I had around a year ago. Providing you can source one second hand it wont cost a fortune to repair but you will need to bleed the system again.

GregE102
Friday 29th October 2010, 00:54
It sound to me like you have a faulty master and or slave cylinder. Its quite a common thing. Saw it on a 2.5 Auto V70 I had around a year ago. Providing you can source one second hand it wont cost a fortune to repair but you will need to bleed the system again.

I will second that!

You are describing exactly the same feeling i got when my master cylinder started to go!

But would bleed your brakes one more time just to make sure!

Greg

wegal
Friday 29th October 2010, 11:01
yup Id agree, rebleed to be certain, if it dont go away its master or slave cylinder seals. Is there are repair kit available for them on these cars ? Most cars you can replace all the internal seals with a cheapish kit

matthewwoodward
Friday 29th October 2010, 12:59
how do u check which cylinder it is?
are they expensive new?

fireclown
Friday 29th October 2010, 13:07
Clamp all your flexible brake pipes. the pedal should be solid. this should eliminate the master cylinder. release each clamp. one at a time. this should help locate where the problem is.

wegal
Friday 29th October 2010, 16:10
or simply start the car, pump the brakes till the pedal goes hard then push hard on the pedal... if it starts to sink then most probably master cylinder, if it doesnt move then there is a problem else where.

GregE102
Friday 29th October 2010, 18:27
Spot on Wegal Thats the way to do it!!

Tim Williams
Friday 29th October 2010, 23:18
If you have no loss of fluid it will be the master cylinder, if you have fluid loss look at all the calipers and if their dry remove the master cylinder and look at the rear of it to see if their is fluid there.

matthewwoodward
Saturday 30th October 2010, 01:38
Thanks guys, will try all these in the morning.

MobyUK
Monday 8th November 2010, 17:06
I have the same problem, seems to be the master cylinder. Any advice about where to buy one apart from the Volvo main dealers.

matthewwoodward
Tuesday 9th November 2010, 12:13
Yeah I have tried all above but still no good, seems like master cylinder for me too :(

Rogerb
Tuesday 16th November 2010, 19:09
I had this problem years ago , with my then nearly new 850R.
Volvo spent a fortune on it , they fitted 4 new master cylinders, bled it no end of times ,new callapers ,pipes ect.

Turned out it was the ABS valve block leaking in to an acululmator internaly,
so when you let your foot off the fluid would go back to the m/c ,so would
show no loss of fluid.

That said in your case try lettin the pads bed in for a bit, also triger the ABS
on a damp pach of road some ware and try rebleading it.

Regards Rogerb