Clutch master cylinder problems

1

109inches

Well-Known Member

Posts

644

Location

Devon

• Aug 1, 2015

• #1

The master cylinder on my 200tdi defender won't pump fluid at all. I've had it all in bits to check the internals and to give a clean. The clutch fluid hadn't been changed for years by the looks of things and was full of gunk. After cleaning it up and inspecting it I expected it to work but no difference.
There is pressure on the outlet of the master cylinder but only of air and not fluid?
I know it's not blocked and it was working fine before I had to undo the rubber hose near the slave cylinder to weld on a new outrigger and all the fluid drained out.
Is it time for a new master cylinder? Or what is the fault? Dos anyone have any suggestions?

 

Al2O3

Well-Known Member

Full Member

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11,032

Location

North of the Wall

• Aug 1, 2015

• #2

Have you changed the seals? If not you might as well buy a new one. £15 to £20 approx

 

1

109inches

Well-Known Member

Posts

644

Location

Devon

• Aug 1, 2015

• #3

Thing is is that it doesn't leak a drop. With a finger covering the outlet pipe the pressure that builds up is great but fluid is not flowing from the resouvoir to the outlet of the master cylinder even tho there are no leaks and all the seals are good.

 

1

109inches

Well-Known Member

Posts

644

Location

Devon

• Aug 2, 2015

• #4

Also the outlet steel pipe snapped just after the master cylinder. What flare is used on the steel pipe?

 

tottot

Well-Known Member

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8,552

Location

west wales coast

• Aug 2, 2015

• #5

If the clutch master cylinder rod is not properly adjusted [some free play at the clutch pedal] fluid will not pass from the reservoir into the cylinder.

 

1

109inches

Well-Known Member

Posts

644

Location

Devon

• Aug 2, 2015

• #6

Thanks for the reply. But what could cause the master cylinder to operate fine and then all the fluid drain from the flexi near the bell housing and then not pump fluid when the master cylinder hadn't been touched at all?

 

tottot

Well-Known Member

Posts

8,552

Location

west wales coast

• Aug 2, 2015

• #7

It may be that when the system ran dry while you were working on it, upon refill of master when you operate the pedal the piston in the master cylinder does not return the full length of the barrel to the position where fluid can enter.[no back pressure from slave cylinders to help] this could be due to the seals being dry or the spring being weak or a bit of both.