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Inadequate clutch throw


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Hello all, Looking for some advice on clutch hydraulics. My TR6 is a rolling rebuild and the clutch hydraulics were weeping so I decided to the hydraulics, Master and slave cylinders and as the pipe snapped both ends when removing a new hose and and pipe were also fitted.  All was working ok before I did the work but now I dont have enough throw to engage the gears as can be seen by the video. 

Also as can be seen by the photo of the dirty slave, it was fitted the wrong side of the plate and also odd was that the master cylinder pushrod had a welded piece added. Any thoughts on what could be going on?

 

 

Thanks

IMG_1967.jpg

IMG_1927.jpg

Edited by timpress
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Hi Tim

looking at the Moss WebCat the SC goes in from the front of the bracket.

Is the push rod on the new SC the same length as the old SC!!!

Should the Bracket be fitted to the front of the GB flange or the rear face !!

Is it the correct SC - have you compared side by side.

 

Roger

Edited by RogerH
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In the non-operated position is the slave piston retracted all the way into the cylinder?  If not you will have lost a bit of what is already restricted throw.  

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How is the clutch pedal free position compared to the brake pedal, is higher or lower?

You may need to consider an adjustable MC pushrod, if that MC is new what is its length, the L/D drive push rod is shorter, (but same cylinder) and has been known to have been swapped, wrong part supplied.

Using the adjustable pushrod will take out any wear in the hole in the pedal, and so will give you back the original stroke length for the MC.

John

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1 hour ago, Steve 286 said:

Have you checked the bore size of the master cylinder you may find you have a small bore one 

The bore is .70 as marked on the one I replaced so I know it was a like for like swap.

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I had the same issue when I fitted mine using all new components including clutch and gear box. Your slave looks to be fitted correctly with the push rod fitted to the middle hole. You need to have around 15mm of travel. An adjustable rod might be required if you have slop in the linkage at the MC, is the clevis pin worn if so replace or weld up the hole and re-drill to accept a new pin.

I had no leaks but could only get limited travel of around 11mm the issue was that there was still air in the system and no amount of two man bleeding would get rid of it after advice from folk on here I bought a Gunson Eazibleed here;

https://www.halfords.com/tools/hand-tools/automotive-tools/gunson-eezibleed-321158.html?cm_mmc=Google+PLA-_-Motoring>Tools>Hand+Tools>Specialist+Automotive+Tools-_-Motoring>Tools>Hand+Tools>Specialist+Automotive+Tools-_-321158&_$ja=tsid:|cid:17363835999|agid:|tid:|crid:|nw:x|rnd:6741221328669818442|dvc:c|adp:|mt:|loc:1007188&gad_source=1&gclid=Cj0KCQiAz8GuBhCxARIsAOpzk8x6xYi3OhawYb41r2_v1sL3F7Oh_cUZm8eHfuRqIIxMxm7tlMIU9PgaAu8UEALw_wcB.

After one use you could see the air being forced out just use 5psi rather than the recommended 10psi it works just as well and is less likely to leak. After which I had 15-16mm and the gears were all easy to get static and I've had no issues on the road. 

Let us know how you get on.

Andy

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52 minutes ago, John L said:

How is the clutch pedal free position compared to the brake pedal, is higher or lower?

You may need to consider an adjustable MC pushrod, if that MC is new what is its length, the L/D drive push rod is shorter, (but same cylinder) and has been known to have been swapped, wrong part supplied.

Using the adjustable pushrod will take out any wear in the hole in the pedal, and so will give you back the original stroke length for the MC.

John

The clutch free position seems lower than the brake before I get friction and hydraulic compression.  Interestingly, this car was a European LHD many many years ago and was converted to RHD so I wonder if I have a different pushrod in the new master cylinder. I only know of adjustable slave cylinder pushrods, not master cylinder though its the master cylinder pushrod on mine that has been modified as per the photo. Seems I may need to take it all apart and do some measuring.

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10 minutes ago, PodOne said:

I had the same issue when I fitted mine using all new components including clutch and gear box. Your slave looks to be fitted correctly with the push rod fitted to the middle hole. You need to have around 15mm of travel. An adjustable rod might be required if you have slop in the linkage at the MC, is the clevis pin worn if so replace or weld up the hole and re-drill to accept a new pin.

I had no leaks but could only get limited travel of around 11mm the issue was that there was still air in the system and no amount of two man bleeding would get rid of it after advice from folk on here I bought a Gunson Eazibleed here;

https://www.halfords.com/tools/hand-tools/automotive-tools/gunson-eezibleed-321158.html?cm_mmc=Google+PLA-_-Motoring>Tools>Hand+Tools>Specialist+Automotive+Tools-_-Motoring>Tools>Hand+Tools>Specialist+Automotive+Tools-_-321158&_$ja=tsid:|cid:17363835999|agid:|tid:|crid:|nw:x|rnd:6741221328669818442|dvc:c|adp:|mt:|loc:1007188&gad_source=1&gclid=Cj0KCQiAz8GuBhCxARIsAOpzk8x6xYi3OhawYb41r2_v1sL3F7Oh_cUZm8eHfuRqIIxMxm7tlMIU9PgaAu8UEALw_wcB.

After one use you could see the air being forced out just use 5psi rather than the recommended 10psi it works just as well and is less likely to leak. After which I had 15-16mm and the gears were all easy to get static and I've had no issues on the road. 

Let us know how you get on.

Andy

I also replaced the clevis pins so no slop at slave or master cylinder but it does make me wonder if I still have air. Certainly didnt seem to have when bleeding but you never know. I have an easybleed but found it threw fluid everywhere (maybe too higher PSI) so I used a vacuum pump and then the wife to help bleed by pushing the pedal.

Edited by timpress
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1 hour ago, RogerH said:

Hi Tim

looking at the Moss WebCat the SC goes in from the front of the bracket.

Is the push rod on the new SC the same length as the old SC!!!

Should the Bracket be fitted to the front of the GB flange or the rear face !!

Is it the correct SC - have you compared side by side.

 

Roger

I beleive I have the SC on the correct side based on other photos and feedback. The SC pushrod is the original one so no issues with that though I may well go down the adjustable SC push road route.

I havent checked the SC side by side but it was from rimmers and was a britpart with the correct Triumph part number. I think it a general part used an many vehicles based on my looking around, just with different OEM part numbers.

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Hi Tim

Here's my saga after I fitted the SC the correct way around it might give you some ideas.

Andy

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Hi Tim,

ask your wife of friend for assitance:

how much way of travel does the lever on the clutch shaft?

Take the rubber off from the slave cylinder --> does the stop clip limit the way of piston travel?

To test this, don't push the pedal too strong. Where does the pedal stop? On the floor or before?

Ciao, Marco

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16 hours ago, RogerH said:

looking at the Moss WebCat the SC goes in from the front of the bracket.

My original Repair Operations Manual shows the opposite - the slave cylinder is inserted into the bracket from the back of the car. When mine was the other way round it was marginal - at full travel the slave piston was close to falling out of the bore. Now it's fine. But slave pushrod length has nothing to do with travel unless it results in the piston popping out.
Cheers,
JC

Edited by JohnC
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6 minutes ago, RogerH said:

the MOss WebCat suggests that the SC goes in from thew front but the bracket is fitted to the rear of the GB flange

I'm not disputing that. But the ROM shows the opposite. Really, it does. But my original Leyland Triumph TR6 Sports Car Parts Catalogue exploded diagram *implies* that the slave is inserted from the front (and its internals are inserted from the rear - go figure). My point is that the ROM has a sketch showing the slave in its installed position.
JC

Edited by JohnC
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9 minutes ago, RogerH said:

I'm sure I read somewhere that there was a conflict in the pictures but not sure which was correct.

Fair enough. I can't claim the ROM is correct. As you say, it conflicts with the parts catalogue. And my slave came with a machined face on the back (i.e. "insert from the front") but that didn't work for me. But knowing that one has a choice may help somebody.

FWIW my Haynes manual also has a sketch showing the slave inserted from the back. I'm not sure if that's good or bad! [edit} and it shows the bracket in front of the engine back plate!
Cheers,
JC

Edited by JohnC
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Operationally it doesn't matter how it is mounted - it just means the rod length needs to be different, to suit.  I expect Tim fitted the new one the same way as the original - which worked with that altered rod.  

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Hi John

I have picture here  numbered  33.15.01 where the SC is being bled and the SC is on the rear of the bracket.

Also 33.35.01 is on the rear.

Fitting as per the ROM makes sense as the bolts are simply locating and not taking all the pressure

 

Roger

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5 minutes ago, RogerH said:

Fitting as per the ROM makes sense as the bolts are simply locating and not taking all the pressure

I hate it when somebody brings logic to an opinion party! That was a joke BTW. Good point. And same to Rob. If it works, chill...
JC

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57 minutes ago, JohnC said:

My original Repair Operations Manual shows the opposite - the slave cylinder is inserted into the bracket from the back of the car. When mine was the other way round it was marginal - at full travel the slave piston was close to falling out of the bore. Now it's fine. But slave pushrod length has nothing to do with travel unless it results in the piston popping out.
Cheers,
JC

It can’t popp out, there is a stop clip.

If the slave cylinder is to far in driving direction, or the rod too short, the way of travel of the piston is limited by the clip.

Simple to make an individual rod with a M8 fork head and a M8 bolt to push the piston deeper in the slave.

Not to the end, stop 6-8 mm before fully in for the wear out of the friction plate!

P1250345-b.JPG.3c0ddd9ffaa5e4cb8c5e4d40173855d9.JPG

If this is the problem!!!

Ciao, Marco

Edited by Z320
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As you have moved the slave cylinder to the correct place and it is the correct one (usually 1 inch bore) and the correct master cylinder 0.70" or 0.75" bore are interchangeable but there are some with the wrong master cylinder push rod. (The same master cylinders with different links are used in some trailer brakes or caravans) A couple of things to consider are whether the air has been bled out (impossible if the slave has been mounted with the bleed nipple at the bottom)

Again it's possible you have the wrong push rod which might cause issues. However it's not normally beneficial to fit an adjustable push rod unless using a pull off spring and end stop. (Sometimes done with some of the alternative release bearings/kits in the past) 

Beyond that you wonder if the operating pin on the clutch shaft has coincidentally decided to fail. 

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Thought I'd bring closure to the topic now I fixed it and let all know what got it working. I needed to use the original modified master cylinder push rod as it was around 10mm longer (see photo) and engaged the pedal at a higher position. The photo is before I removed the new pushrod and measured but this quick check proved my thoughts. Not sure why the master cylinder pushrod was modified but clearly whoever had the car in the past had to work on the hydraulics and had the same issue and modified it.

Any way, all good now and thanks all for the advise. 

IMG_1974.jpg

Edited by timpress
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