Clutch Hydraulics Recovered - I hope

billcoleman · 8th August 2016, 21:50

I had to replace my Slave and Master cylinders at about 100,000 miles. As per recommendations on this forum I used a Land Rover CSC and was expecting the entire system to last another 100,000 miles.

So you can imagine my dome and gloom when driving back from Heathrow on Friday night when I could definitely tell that the clutch was getting lower and gearshifts harder.

I recall on the last occasion that I bled the system as others have managed to save their hydraulics, but for me the CSC failed very shortly after bleeding the system.

This made me think about the bleeding process - if the problem is really the Master cylinder and you bleed the system in the normal way, then you are just pushing all the debris down the line into the CSC and there is no way that pumping the pedal will get enough flow to blow the debris out. If you look at the inlet and vent ports, they are at the top of the slave, so all the bits go in and stay in the bottom which just results in the slave seals failing.

Fortunately I already had a spare Master, so I pulled out the old one to inspect, and sure enough there was almost no fluid in it. I can only assume that the fluid has been used as the clutch has worn. But worse than that, the fluid that remained was like dirty oil and the rubber inner sleeve was falling apart.

I have a Sealey brake bleeding kit that you can use to pressurize the brake system from the Master reservoir to flow the fluid through, so using the old Clutch master hydraulic line quick release coupling, I made an adapter that connected the bleeding kit straight to the short hydraulic line up to the slave. This allowed me to bleed just the CSC without pushing more debris into the slave, also the bleeding kit allows a pretty good flow of fluid.

The result was that some pretty dirty oil was flushed-out, but not too many big bits. Before finishing, I also pumped up the pressure and left it at about 35psi for an hour, and there was no pressure drop. So I'm pretty happy that the seals are ok. Doing a bit of research, the CSC can operate at pressures of up to 45bar (675psi), so 35psi wont do any harm.

Finally, before fitting the new Master, I flushed that through as well to make sure that the fluid was a good quality one. Also it looked like there was a lot of white grease mixed in with the original fluid, so I wonder if that degrades the fluid over time.

The result seems to be ok and the clutch now feels great.

I know that this seems a bit of a long story, but if it saves someone having to replace a perfectly good clutch (which is a hell of job to do) and just replace the Master plus a flush of the slave, then it is definitely worth it.

If anyone wants to borrow my adapter, I am sure we can sort something out. Also, the Sealey Reservoir adapter fits both the brake and clutch master cylinder reservoirs, so maybe I will flush the clutch out once a year from now on with a good fast flow through the system.

marinabrian · 9th August 2016, 07:01

I was thinking along the exact same lines as you Bill when I made this

And the only additional thing I did in terms of the master cylinder, was to remove the piston entirely, take of the white cap at the end of the pushrod and clean the gunge out of the non return valve prior to reassembly and bleeding, prior to connecting up to the newly fitted CSC.

The result was a clutch which was easily as light as an 1800

Lovely

Brian

Quote:

Originally Posted by billcoleman

I had to replace my Slave and Master cylinders at about 100,000 miles. As per recommendations on this forum I used a Land Rover CSC and was expecting the entire system to last another 100,000 miles.

So you can imagine my dome and gloom when driving back from Heathrow on Friday night when I could definitely tell that the clutch was getting lower and gearshifts harder.

I recall on the last occasion that I bled the system as others have managed to save their hydraulics, but for me the CSC failed very shortly after bleeding the system.

This made me think about the bleeding process - if the problem is really the Master cylinder and you bleed the system in the normal way, then you are just pushing all the debris down the line into the CSC and there is no way that pumping the pedal will get enough flow to blow the debris out. If you look at the inlet and vent ports, they are at the top of the slave, so all the bits go in and stay in the bottom which just results in the slave seals failing.

Fortunately I already had a spare Master, so I pulled out the old one to inspect, and sure enough there was almost no fluid in it. I can only assume that the fluid has been used as the clutch has worn. But worse than that, the fluid that remained was like dirty oil and the rubber inner sleeve was falling apart.

I have a Sealey brake bleeding kit that you can use to pressurize the brake system from the Master reservoir to flow the fluid through, so using the old Clutch master hydraulic line quick release coupling, I made an adapter that connected the bleeding kit straight to the short hydraulic line up to the slave. This allowed me to bleed just the CSC without pushing more debris into the slave, also the bleeding kit allows a pretty good flow of fluid.

The result was that some pretty dirty oil was flushed-out, but not too many big bits. Before finishing, I also pumped up the pressure and left it at about 35psi for an hour, and there was no pressure drop. So I'm pretty happy that the seals are ok. Doing a bit of research, the CSC can operate at pressures of up to 45bar (675psi), so 35psi wont do any harm.

Finally, before fitting the new Master, I flushed that through as well to make sure that the fluid was a good quality one. Also it looked like there was a lot of white grease mixed in with the original fluid, so I wonder if that degrades the fluid over time.

The result seems to be ok and the clutch now feels great.

I know that this seems a bit of a long story, but if it saves someone having to replace a perfectly good clutch (which is a hell of job to do) and just replace the Master plus a flush of the slave, then it is definitely worth it.

If anyone wants to borrow my adapter, I am sure we can sort something out. Also, the Sealey Reservoir adapter fits both the brake and clutch master cylinder reservoirs, so maybe I will flush the clutch out once a year from now on with a good fast flow through the system.

billcoleman · 9th August 2016, 10:03

Looks similar to my adapter, but mine is to flush down through the slave from the middle connection.
[URL="https://1drv.ms/i/s!AnnwjmugfqN2gqJ2YfopGxv_6xvRTg"]

Bill

8th August 2016, 21:50	#1
billcoleman Gets stuck in MGZT-T Join Date: Aug 2007 Location: Bournemouth Posts: 578 Thanks: 7 Thanked 27 Times in 24 Posts	Clutch Hydraulics Recovered - I hope I had to replace my Slave and Master cylinders at about 100,000 miles. As per recommendations on this forum I used a Land Rover CSC and was expecting the entire system to last another 100,000 miles. So you can imagine my dome and gloom when driving back from Heathrow on Friday night when I could definitely tell that the clutch was getting lower and gearshifts harder. I recall on the last occasion that I bled the system as others have managed to save their hydraulics, but for me the CSC failed very shortly after bleeding the system. This made me think about the bleeding process - if the problem is really the Master cylinder and you bleed the system in the normal way, then you are just pushing all the debris down the line into the CSC and there is no way that pumping the pedal will get enough flow to blow the debris out. If you look at the inlet and vent ports, they are at the top of the slave, so all the bits go in and stay in the bottom which just results in the slave seals failing. Fortunately I already had a spare Master, so I pulled out the old one to inspect, and sure enough there was almost no fluid in it. I can only assume that the fluid has been used as the clutch has worn. But worse than that, the fluid that remained was like dirty oil and the rubber inner sleeve was falling apart. I have a Sealey brake bleeding kit that you can use to pressurize the brake system from the Master reservoir to flow the fluid through, so using the old Clutch master hydraulic line quick release coupling, I made an adapter that connected the bleeding kit straight to the short hydraulic line up to the slave. This allowed me to bleed just the CSC without pushing more debris into the slave, also the bleeding kit allows a pretty good flow of fluid. The result was that some pretty dirty oil was flushed-out, but not too many big bits. Before finishing, I also pumped up the pressure and left it at about 35psi for an hour, and there was no pressure drop. So I'm pretty happy that the seals are ok. Doing a bit of research, the CSC can operate at pressures of up to 45bar (675psi), so 35psi wont do any harm. Finally, before fitting the new Master, I flushed that through as well to make sure that the fluid was a good quality one. Also it looked like there was a lot of white grease mixed in with the original fluid, so I wonder if that degrades the fluid over time. The result seems to be ok and the clutch now feels great. I know that this seems a bit of a long story, but if it saves someone having to replace a perfectly good clutch (which is a hell of job to do) and just replace the Master plus a flush of the slave, then it is definitely worth it. If anyone wants to borrow my adapter, I am sure we can sort something out. Also, the Sealey Reservoir adapter fits both the brake and clutch master cylinder reservoirs, so maybe I will flush the clutch out once a year from now on with a good fast flow through the system.

9th August 2016, 10:03	#3
billcoleman Gets stuck in MGZT-T Join Date: Aug 2007 Location: Bournemouth Posts: 578 Thanks: 7 Thanked 27 Times in 24 Posts	Looks similar to my adapter, but mine is to flush down through the slave from the middle connection. [URL="https://1drv.ms/i/s!AnnwjmugfqN2gqJ2YfopGxv_6xvRTg"] Bill Last edited by billcoleman; 12th August 2016 at 22:18..