V8 clutch master removal.

jp928

jp928

Well-Known Member
Also posted on my project thread. Want to replace clutch master, but where the book shows the pushrod connected to the lever with a clevis pin and R clip, mine has a bolt head, which is VERY hard to turn. Cant see whats on the other side. Thinking of removing the whole cylinder support assembly, but...If I remove the short lever from the clutch pedal shaft will that expose me to things being impossible to reassemble? There is a 3rd bolt (255231) shown in the parts book low down that only seems to have a clip on it, but in real life it seems to be the attachment for the reserve tap bracket?
All suggestions welcome.
EDIT:- Looking up in the book about setting the pushrod length, the text says 120mm from centre of yoke hole to mounting flange, but diagram shows measurement from yoke to end of cylinder body...??? Separately on setting pedal height to match brake pedal height it says to adjust pushrod length at the master cyl to achieve correct height. Makes me wonder a bit .
thanks
 
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TRying now. What a b@stard. Clamped the supply hose oK. Undid the bolt acting a a clevis pin - yet to find out how that works - suspect nut on the other side. got the rear fixing out - complete stud came out. front more difficult, but eventually got the nut off. undo the input/output pipes/hoses. cant move cylinder for love nor $. Initially thought it was binding on the front stud, so with some difficulty got the stud out with double nuts. Still wont lift at all. tried levering at each end with a screwdriver , but little progress. after a thorough search for any other nuts/bolts I put a shifter on it from above and tried twisting -started to get some movement. eventually it lifted- the boot wasnt terrible,but something had glued it in place. There was a nut brazed on the back side of the pushrod yoke, and there was visible wear on the clevis bolt where it worked on the lever from the pedal shaft. Get new cylinder ready. Going to use new bolts on the fixings. Front one very difficult to get started, so I ran a new bolt right through the hole. Got the new cylinder in place, started the bolts well in, then found I couldnt get the output tube nut started because the cylinder was too rigid. Out with bolts, got the output started , input was harder, but eventually went in, feeling fine - not cross threaded - nipped both lines up gently. take clamp off input hose as its getting in the way. now the bolts - front was a real pain to get started. by the time I am getting the front bolt close to done I find there is a slow leak at the input tube nut - tighten it up , but its taking quite a load. looks straight, first turns in were smooth, but needed a spanner, too hard for fingers. Thats all I can manage today. The old cylinder was wet and messy so it would have to be done in the not too distant, and its much easier with the engine tilted.
Hard to believe nobody here has ever done this before.

5EhpTZj.jpg
 
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I stripped my engine bay on Wednesday which included the clutch master cylinder and it was a pig of a job even without the engine. I had also removed the steering box, brake/clutch fluid reservoir, pedal box, heater and everything else including the front crossmember (the one with the bonnet catch).

Mine was an auto to start with, so this had been bodged in so wouldn't be the same as yours. The clevis pin was a dome with a small hex type allen key fitting and after spending ages trying to get something to fit it to undo it, I found that it had no nut, it had just been pushed in. and I just pulled it out.

I undid the two nuts and tried to extract the cylinder, but it wouldn't budge. Eventually I found the only way to remove it was to remove the whole bracket as one unit.
 
I thought about removing the whole bracket. in the parts book it looks like the bottom bolt supports the reserve tap somehow, but as soon as I turned the nut there it spun the bolt - the locknut shown in the book doesnt seem to be there. Didnt want to complicate things by undoing the reserve as well, its already bigger than Ben Hur!
 
Here is the old cylinder's back end....Replacement overdue I think.

Um0qxp4.jpg


Found the cause of the inlet leak - locally bought generic cylinder - inlet port thread not cut deep enough to have the tube nut seal the flare against its seat. bummer. have run a thread chaser in a few times, and now it jams the pipe in firmly. Flushed it out with brake fluid before reassembling. The outlet port looks and feels OK when fitting its tube nut.
Chased the thread of the front stud on the mount, and fitted the stud. Re chasers, highly recommend Lang 2581 imperial Thread chaser set, using them a lot lately. Planning to replace the inlet rubber hoses, suspect they are past their best.
 
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nearly there. Got the cylinder into place, started front nut, started outlet pipe, inlet pipe already in place. Tried to fit a piece of 1/4" hose on the inlet, but no way I could get it over the barb on the reservoir. Fitted a piece of 5/16 hose, clamped it up, but as soon as I put fluid in the reservoir it pissed out the inlet pipe joint, so I had to go back to the original hose. All bolted down now, no leaks. ned to find a new clevis bolt - old one is worn. Nextjob is underneath (after cleaning up the spilt fluid!) to fit the new slave cylinder.
Somewhere I have seen somebody say that a clutch fluid leak would not compromise the supply of fluid to the brakes. In my case when the fluid ran out the clutch master supply line it seemed to completely empty the tank - I could see the outlet holle for the clutch master (from looking into the tank from above) and I could not see any sort of upward tube that would leave some fluid behind....???
 
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I recall that the clevis pin on my clutch master pushrod was this type Clevis Pin 8mm x 32mm in A4 Stainless - Westfield Fasteners Ltd

To get to the rear to install a split pin was a non starter. I came up with the idea of using an R clip, but kept dropping that, in the end I put the R clip on a length of lockwire and managed to fiddle it in place and then tied up the wire in order to be able to remove the clip if needed.
 
I had thought to undo the nut holding the lever onto the clutch pedal shaft, slip the lever off and that would allow the pushrod to rotate and give access to the rear of the clevis.
 
jp928 said:
Somewhere I have seen somebody say that a clutch fluid leak would not compromise the supply of fluid to the brakes.
Click to expand...

Well, if the clutch/brake fluid ran out because of the leak in the clutch system, the brakes would still work for a while as they only require some extra fluid when the pads wear, but you only have the fluid in the hose from the reservoir to the master cylinder so not much in the way of back up.
 
Hi, The fluid reservoir isn't like the fuel tank with two different length pipes. There's a barrier or dam across the middle between the two outlet pipes in effect creating two small reservoirs and the bulk of the fluid above, so both don't run out together. (Unless there's two leaks:) ).

Colin
 
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