Changing clutch cylinders

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.

trucker5774

New Member
Posts
120
I have a 2002 disco td5 with a low biting clutch pedal, so after a life time of bleeding it with no improvement I have decided to change both the master and slave cylinders.
The master is a doddle to get off but the slave is a pain. It's really hard to get to the mounting bolts. When you do find the right combination of socket/extension, you can just get one click on the ratchet giving about 1/8th of a turn:frusty:. The bolts were very tight in the threads too.
My questions are to do with the rod from the slave, first. I assume it aligns dead centre into the housing aperture. What is the chance of not locating it correctly when I reassemble it? There is no way to look into the opening. Initially I was taking it of to inspect it, but for the cost of a new cylinder and the grief of the access, there is no way I would not replace it.;)
As for the master, on examination it "appears" OK. My guess is that the piston seals are fooked and their was quite a bit of ****e built up on the piston shaft. To test it, I drew the piston back and poured some fluid in the outlet. As I then pushed the piston in, as would be the case when pressing the pedal, I expected to feel quite some pressure on my finger over the outlet..........that didn't seem to be the case.....any comments?
I will get replacements and get on with it. I just thought it would be worth a post as so many people seem to be having the same issue. Perhaps a recent post will make searching easier (assuming I sort it and all goes to plan):confused2:
 
you can tell if seals are poor as it will be wet where rod sits nothing ever goes wrong with rod or release arm on td5s unlike 300 release arm,likewise master will be wet where push rod enters or blow back in reservoir
 
you can tell if seals are poor as it will be wet where rod sits nothing ever goes wrong with rod or release arm on td5s unlike 300 release arm,likewise master will be wet where push rod enters or blow back in reservoir
There are no obvious leaks. I was thinking perhaps the piston seals are allow in fluid past them within the confines of the cylinder, so not giving a "full" pedal. Whatever the problem, I may as well change them now they are off, so at least when I bleed it next I know it's me and not the cylinders:eek:

I am reckoning that the push rod from the slave will self centralise as I reassemble.
 
i had the same problem poor clutch with no leak from the bellhousing so i just changed the master cylinder and that was no better so i then changed the slave cylinder that sorted the problem must have been sucking the air in and like you point out its not the easyest of jobs the exhauts makes the job even more a pain

but the rod should not come out it should be fixed to the clutch arm with a little plastic clip (like the old tdis) this will keep the rod inplace

and when i fitted the new slave cylinder i fitted it upside down (bleed nipple at the bottom) then back bead the system
 
i had the same problem poor clutch with no leak from the bellhousing so i just changed the master cylinder and that was no better so i then changed the slave cylinder that sorted the problem must have been sucking the air in and like you point out its not the easyest of jobs the exhauts makes the job even more a pain

but the rod should not come out it should be fixed to the clutch arm with a little plastic clip (like the old tdis) this will keep the rod inplace

and when i fitted the new slave cylinder i fitted it upside down (bleed nipple at the bottom) then back bead the system

My rod is definitely not fixed. Maybe the clip is just not holding it in and it will be fine.............or maybe this is the low bite issue?

I will have to get a mirror and a lamp to have a look.

What did you use to force the fluid backwards?
 
i used an old screen wash pump and tank(off my old 90) to back bleed (one off any scrap car will do) but you can use an oil can the type you pump with your thum or buy a propper kit from any auto factors or halfords
 
Progress so far.......
New slave fitted,although I believe the old one was OK. The clutch bite is still close to the floor. I have bled it to every joint and to the nipple and am as sure as I can be that there is no air in it.

When the clutch pedal is held to the floor and I open the bled on the slave I can hear the clutch arm return and fluid is force out of the nipple.

The gears are smooth to select but the bite needs a toe pointed foot and is a pain in the arse after a while.

Is it still likely to need a master? There are no leaks. Could the fluid be passing the piston seal within the master cylinder so that the piston is moving within the fluid and not exerting full pressure?

The bite point is consistent and does not change with pedal pumping. I am happy to change the master, but don't want to just waste the money if there is another fix...............by the way , what is that disc shaped fitting on the underside of the master/

The clutch itself seems strong. I cannot induce any slipping by starting in a high gear with the brakes on or any other way.

Lots of questions, I know, but can anyone help. Maybe you have had all the same symptoms with no apparent faults, then replaced the master and it was sorted?

Opinions please guys
 
you could try sligthly longer push rod between slave and relesae arm ive had to do it before after ensuring everything else was okay ,ive even come across wrong rod fitted ,they used to put shims in between slave and housing that could be removed added to get good pedal,i have most rods so might be able to help if you can give me your rod lenght
 
you could try sligthly longer push rod between slave and relesae arm ive had to do it before after ensuring everything else was okay ,ive even come across wrong rod fitted ,they used to put shims in between slave and housing that could be removed added to get good pedal,i have most rods so might be able to help if you can give me your rod lenght

Thanks James, very good of you. This did cross my mind to the point where I measured the depth the rod goes into the slave to see how much more the piston could be pushed back towards the nipple before it bottomed out. It left 10mm of piston travel. it crossed my mind to put some sort of packer in the slave, but couldn't think of anything suitable and thought that the 10mm may be needed as a tolerance.
I have been unsure as to whether I could remove the push rod. (so I don't know it's length) I keep reading about the securing clip on the release arm and didn't know if I could withdraw it without the clip falling of or creating some sort of other problem. I'm not really wanting to pull the gearbox out.

I also wondered if the release arm could be to blame.....bent or distorted? This would give the same effect.

My gut feeling, though, is that the pedal should feel "better". As I press it it has perhaps 25mm of free travel then gentle resistance which increases slightly at the bottom of the travel. I just feel that it could give a bit more "earl feel". Its only on release that that the problem really shows, with the bite being very close to the floor.

Do you think its worth measuring the rod based on what I have described? Is it safe to just pull it out?
 
you can measure it without removing rod,arm is cast so wont bend or wear like earlier 300s pressed steel but there is nylon socket in arm that pivot fits in if worn or missing would loose you pedal travel,measure it and let me know if i have longer rod i will give you some shims that go between slave and box to give you more adjustment,if rod pulls out it can be held in place while carefully using slave to hold it in once up it wont go anywhere
 
you can measure it without removing rod,arm is cast so wont bend or wear like earlier 300s pressed steel but there is nylon socket in arm that pivot fits in if worn or missing would loose you pedal travel,measure it and let me know if i have longer rod i will give you some shims that go between slave and box to give you more adjustment,if rod pulls out it can be held in place while carefully using slave to hold it in once up it wont go anywhere

I hear what you are saying. It's not likely to be a long rod with these symptoms so shims would make it worse. I have looked as far as I can into the bell housing using a mirror and torch. The end of the rod goes into a black clip/socket, so I could only measure up to that without removing the rod and have no way of knowing how much of the rod is set into the clip, especially if the clip/socket is worn. I assume the end of the rod has a ball shape to it, to sit in the socket. The socket is presumably clipped to the release arm and would stay in place if I just withdraw the rod?

Sorry to go on, it's 20 years since I last lay on my back wrestling a gearbox out. It's about the same time since I owned a land rover too. I luckily never had to do any work on the other 3, although they would have been more "agricultural"
 
i meant if you put in longer rod then used shims to reduce it if it was too long

Sorry James, I'm with you now. I would still need to measure it to work out the new length and shim size..........either way it would have to come out..............just to put the new one in!

Dare I pull it out?
 
When you say "you have don it a few times" are you referring to replacing the clip if it falls away? If so how do you retrieve it? Could a new clip be the answer to lengthening the rod?
 
no leave clip off ,just hold rod in socket while holding other end with slave and pushing up without letting rod drop once up rod wont move
 
Thanks for taking the time to trawl through my questions. If I had clutch set up to view on a bench I would know all the answers. The problem is just not being able to see it through the slave mounting. I will probably be fitting a master cylinder in due course, regardless. I don't suppose you know the length of the standard push rod?
 
I was about to strip the slave again and then gave it some more thought.

The system must be designed to move the push rod and thus the release arm a given distance when the clutch pedal is pressed. This made me think.......even if the push rod was lengthened (or shortened), surely all that would do is alter how much fluid was in the system as there is no "free play" as such. Lets assume that the slave movement is designed to use 70% of its available piston length, then it would just use the first middle or last 70%, as there is fluid occupying the space, the piston is always in contact with the push rod.

That suggests to me that the master cylinder, for some reason is not moving any, or enough fluid at the early part of the stroke, resulting in a late clutch release and therefore an early bite point when the pedal is raised again.

Does that all sound reasonable?...........Still waiting on a new master anyway.
 
try master first , as did say altering rod was last thing after everything else proved right but moving effective stroke does make a difference
 
Back
Top