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hydraulic clutch went to floor, why?
02GF74 - 8/8/16 at 06:04 PM

Volvo 850 manual with hydraulic clutch.

Drive to norfolk yesterday, hot day, maybe 26c and was in queue of stop, move 2m, stop type traffic.

10 mins of this, put foot on clutch and it sinks without any resistance to the floor. Couldnt engage gear so lifted bonnet, nothing obviously wrong, brake reserviour level ok (i believe clutch shares the fluid).

Vet back in, depress clutch few more times, possibly pressed brake pedal, start engine and clutch bacm to nornal. No problems for the next 150 miles.

So wtf happened?

Im guessing got a vapour in clutch pipe that then cleared itself. But why, never happened before. Or is it sign seals are failing in master or slave cylinders?

[Edited on 8/8/16 by 02GF74]


theconrodkid - 8/8/16 at 06:19 PM

prolly the fluid has boiled,when was the last time it was changed ?


SteveWalker - 8/8/16 at 06:21 PM

Whatever it was, I'd either want to find out or replace anything that it might have been. Years ago, a friend was driving his heavily modified Mini in stop start traffic when the same thing happened to him - except that he was coming to a stop, not setting off and went into the back of the car in front.


r1_pete - 8/8/16 at 06:34 PM

Flexible hoses could be balooning with the heat, maybe pumping the brake moved enough fluid to cool it...


rusty nuts - 8/8/16 at 07:22 PM

Sounds like it could be a dodgy master cylinder ? I've had similar problems in the past during hot weather


adithorp - 8/8/16 at 08:33 PM

quote:
Originally posted by rusty nuts
Sounds like it could be a dodgy master cylinder ? I've had similar problems in the past during hot weather


Sounds like it to me. It'll probably not do it again until you a) forget about it, and b) are somewhere critical.


nick205 - 9/8/16 at 08:48 AM

I'd get a cost for replacing the master cylinder and the fluid - probably not that pricey and would provide some piece of mind. I've opted to replace brake fluid every 2 years in various cars and it does make a difference to the feel and performance of the brakes.


Slimy38 - 9/8/16 at 09:08 AM

My Toledo did exactly the same going round West Midlands safari park. I was in neutral and couldn't get into gear. Once I got the car cooled down and then moving, it recovered. I changed the fluid that weekend (the old stuff was more like pond water than brake fluid), and it was fine up until I sold the car.


axle - 9/8/16 at 09:32 AM

strip MC clean everything with methylated spirit if all look OK assemble with fresh the fluid , but the seals could well passed their best!


coyoteboy - 9/8/16 at 11:59 AM

My 370z did this a while back, after a bit of clutch abuse. I put it down to boiled clutch fluid due to the concentric slave being right on top of the clutch. Never done it since, but likewise I should flush the fluid.

Look out for fluid leaks from clutch just in case.


nick205 - 12/8/16 at 08:47 AM

You may already be a member, but could a Volvo forum provide any info...

http://www.volvoforums.org.uk/


nero1701 - 14/8/16 at 03:46 PM

I have a FN2 Civic type R, I had the clutch release bearing break a few weeks back, so, as I was going to be in there, i changed the whole clutch, pressure plate and release bearing.

Went on holiday a couple of weeks later so had only done a few miles.

Came back from holiday and had surgery a couple days after so couldn't drive.

Get in the car bout a week and a half later (cars been laid up totalof 18-20 days) and its a bit 'notchy' changing gears. within 30 miles, clutch to the floor, presumed perhaps i hadn't bled it properly, re bled.. 30 miles later, clutch to the floor?

Disconnected the slave and had my mate operat clutch..slave hardly moved..replaced slave..

30 miles later...Clutch to the floor.....AA called....


Turns out there was a leak in the Clutch hydraulic damper...

£25 for a hose to be made to bypass the bugger!!

when it arrives ill let you know how i get on!