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Spitfire Clutch Slave and master replacement , 78 Spitfire

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J

Joe_Pinehill

Jedi Hopeful
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My clutch slave seems like its leaking slightly. It looks pretty
straight forward to replace. Is it as easy as it looks? Just remove
bolt, and replace/bleed new ?

I was going to order a whole kit, replace the Slave, Master and Line all at the same time. Thinking its easier to start with all new parts in the reassembly.

It looks like the slave and all, are accessible from underneath while the car is on ramps. The hard part seems like working underneath the car. Any tricks to refitting the slave? thanks
 
Pretty straightforward. You will want to suck some of the hydraulic fluid out of the master cylinder first. Then disconnect the hydraulic line at the slave and let it drain out.

One bolt to undo and then wiggle and pull the slave cylinder out.

On reassembly, make sure the slave push rod is centralized in the housing, slide it in, line up the groove with the locating hole, bolt it in.

Reconnect the hydraulic line, add new fluid, and bleed it all out.
 
Re: Clutch Slave and master replacement , 78 Spitf

Thanks, is it a job I can do from under the car? On another forum a poster advised removing the tunnel, and accessing form the top. Which I would rather not do.
 
Re: Clutch Slave and master replacement , 78 Spitf

Yeah, it's definitely easier with the tunnel out. Trouble is, that's a whole lotta work to get at either the bolt holding the slave in its bracket or to the two bolts holding the slave and bracket to the bellhousing. Leaving the tunnel in place might lead to a skinned knuckle or two...and possibly to some blue language, but odds are you can save a good bit of time NOT removing half the interior. /ubbthreads/images/graemlins/crazy.gif

It is definitely a bit easier to first loosen the line from the slave, but you can actually withdraw everything as a unit without opening the hydraulic system at all. Takes a bit of maneuvering, but it's doable. (I've actually done this in the past between cars in an attempt to diagnose a clutch problem!)

And unless you're in a desperate hurry to get this all done, consider rebuilding the cylinders if possible. In my experience, it's rather rare to have either cylinder be so damaged that it can't be easily honed (if necessary) and have new seals installed.
 
Re: Clutch Slave and master replacement , 78 Spitf

Just to add to Andy's note, you should be able to get at it all from underneath with the car on jackstands. If you are just pulling the slave out, you should not need to get at the two bolts he mentions. Have a look under the car and see where the 'clinch' bolt is that holds the slave into that housing. That's the one you need to undo. If you can see it ok and the bolt and nut are accessible, you should be ok. Sometimes its difficult to get at the nut. You should not have to remove the part that's attaches it to the bell housing if you just want to remove the slave, but once the slave is out, that 'boss' housing is fairly easy to get at too.

I would second his thought about rebuild versus replace. If the cylinders are in good shape (i.e. not deeply scored), all you really need is a kit with seals, etc to rebuild. You may need to touch up the cylinders with a hone. Or I have used just a suitably sized piece of wooden dowel wrapped with 450-500 grit sandpaper to lightly remove scuffs. You're going to wind up taking them apart anyway, might as well have a look and see if you can get by with the rebuild kit. You're talking $10-15 for kits versus $100-135 for cylinders.
 
Re: Clutch Slave and master replacement , 78 Spitf

thanks for the advice, Im going to try underneath first.

All the postings ive read on rebuilding brake masters seem to advise not to try, Do you generally have more luck with rebuilding a clutch slave?
 
Re: Clutch Slave and master replacement , 78 Spitf

[ QUOTE ]
All the postings ive read on rebuilding brake masters seem to advise not to try, Do you generally have more luck with rebuilding a clutch slave?

[/ QUOTE ]Personally, I've found only two factors work AGAINST rebuilding:

1. There is obvious physical damage to the bore of the cylinder or piston; or
2. You can't obtain a good quality rebuild kit.

All that really "wears out" is the seal, in most cases. Sometimes you will get a badly enough pitted or scored cylinder wall that the damage can't be honed away. And sometimes it is difficult to find a quality rebuild kit. I personally will not use anything except an OEM kit; for the old Girling cylinders that currently means either a TRW/Lucas brand or (if memory serves) TVS from Europe. There are kits with very hard, almost "plastic," seals that I will not use!
 
Re: Clutch Slave and master replacement , 78 Spitf

Tip:

If you have never removed a clutch slave in these cars, make sure you remove the bolt entirely. It is not just a cinching bolt, it also retains the slave. You'll see when you take it out. Also, try a rubber hammer and lightly tap slave to loosen - sometimes it can bond to the steel bell housing. It's a better option than marring the surface with something else.
Do not over-tighten the bleed screw. I am a careful mechanic and managed to blow out the threads in my original that I had planned to rebuild, now I have a nice shiny new expensive slave cylinder!

Adam H.
____________________________________________________________
1972 Triumph Spitfire.
 
Re: Clutch Slave and master replacement , 78 Spitf

Maybe Ill order the rebuild kit and a new slave. If the slaves looks rebuildable, return the new one, if not just replace.

It would be more satisfying to rebuild for $10 vs new for $70.
 
Re: Clutch Slave and master replacement , 78 Spitf

Makes sense to me. I would take that approach for both master and slave.

One last point, don't over-hone the cylinder. As Andy said, if its badly pitted or scored you are going to have to replace it. If you sand it down too much the seal will not seal any more. There's no way of fixing this. Just lightly touch it up. All you're trying to do is have the cylinder nice and smooth so it doesn't tear or unduly wear the edge of the new seal.

Use brake fluid to clean and lubricate the new seals, etc. Don't use anything else. (ok, so technically there were two last points....)
 
Re: Clutch Slave and master replacement , 78 Spitf

[ QUOTE ]
...As Andy said, if its badly pitted or scored you are going to have to replace it. If you sand it down too much the seal will not seal any more. There's no way of fixing this....

[/ QUOTE ]Theoretically, the cylinders could be resleeved, but it seems pointless on cylinders that are still commonly available new and probably in good, used, rebuildable condition...and not all that expensive either new or used! /ubbthreads/images/graemlins/smile.gif
 
Re: Clutch Slave and master replacement , 78 Spitf

Sorry to keep beating this, but when the slave is removed, does the pushrod stay attached to the clutch plate, or come out with the slave cylinder?
 
NewClutch Slave installed thanks

thanks for all your help. I pulled the tunnel out, and it was a snap, about an hour and all done.
 
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