DIY - Swap clutch slave cylinder and hydraulic line for improved feel and control

[ls1ac]

Every once in a while I have come across a slave that just dose not want to bleed all the air out with the pedal method. I have found that after trying the pedal then using the vacuum bleeder then back to pedal method will clear the bubble from the system.
Just 2c worth.

[keithr]

I'm considering doing this, and possibly changing the line at the same time (because racecar).

I removed my spring a long time ago... it was a significant improvement. I'm interested to try this.

It's been a while since this thread was active, but I'm curious about a couple things:

Originally Posted by Ultramaroon

Caution: Monitor the fluid level in the reservoir carefully. If the master cylinder is allowed to suck air, bench bleeding will be required to restore function.

Can you elaborate? Air is going to get into the system one way or another when swapping the slave and/or line. Naturally you'd want to avoid getting any more in than necessary, but how is sucking air through the reservoir so much worse than the air that gets in via the other procedures? And, should that occur, what does a bench bleed involve? I've searched around and information is a bit inconclusive on the topic.

Over here and here, you mention needing to add a bit of grease to the pushrod (OP not updated). I assume this is the same method discussed in the squeaky clutch thread(s) for those who aren't replacing the slave cylinder. Is there more to the process? Because, I also have the squeaks and would like to resolve it all while I'm in there poking around.

Thanks!

[Ultramaroon]

Originally Posted by keithr

Can you elaborate? Air is going to get into the system one way or another when swapping the slave and/or line. Naturally you'd want to avoid getting any more in than necessary, but how is sucking air through the reservoir so much worse than the air that gets in via the other procedures? And, should that occur, what does a bench bleed involve? I've searched around and information is a bit inconclusive on the topic.

I've never had trouble with sucking air into a clutch master but I have had to bench bleed new brake masters and it's a PITA; special fittings, tubes, futzing with it, reinstalling, all while trying not to spill brake fluid everywhere.

On a master cylinder there isn't a specific port with a bleed nipple at the high point. That's why the outlets have to be connected back to the reservoir with hoses, then pump and pump until all the bubbles are gone.

Then, either plug the ports, or keep the hoses in place while re-mounting the cylinder. Quickly swap the fittings for the real ones, and finish off bleeding again.

I don't know if this is really necessary for this clutch master but I put the standard warning out there just to be safe.

Over here and here, you mention needing to add a bit of grease to the pushrod (OP not updated). I assume this is the same method discussed in the squeaky clutch thread(s) for those who aren't replacing the slave cylinder. Is there more to the process? Because, I also have the squeaks and would like to resolve it all while I'm in there poking around.

I've been lazy.

In one of those squeaky clutch threads I posted this image.





As long as you have the slave cylinder detached, you can remove the rubber boot from the fork and reach down behind it with your finger. That's where it squeaks. You should be able to touch that big ball & socket. There's a wire clip that holds it together but don't let that distract you.

If you can reach it with your finger, you can get a dab of grease down in there. That's the most you can do without dropping the transmission.

Good luck.

[keithr]

Originally Posted by Ultramaroon

In one of those squeaky clutch threads I posted this image.

Pic isn't showing up, but I'm pretty sure I know what you're talking about. I saw a video someone posted where they had the transmission out and showed the noisy fork and where to lube it. Hopefully I can get my finger in there [giggity], or else I'll have to ask the missus to ruin her manicure and try to reach it for me.

Thanks for the info.

[Ultramaroon]

Originally Posted by keithr

Pic isn't showing up, but I'm pretty sure I know what you're talking about. I saw a video someone posted where they had the transmission out and showed the noisy fork and where to lube it. Hopefully I can get my finger in there [giggity], or else I'll have to ask the missus to ruin her manicure and try to reach it for me.

Thanks for the info.

Whoops, fixed.

[Jamestl]

Hi all - really interesting thread. I'm a relatively new member and I've read quite abit but unsure on my three options for better shifting in this car. Trying to decide between the TRD short shifter, the clutch slave swap, and or the clutch spring removal. Anyone who has I'm done two or three of the above and can comment on the relative merit of doing them together? I'm not dissatisfied with the throws of the stock shifter, but the clutch feels very vague so that would be my priority. Thanks for any feedback!!

[treminaor]

Originally Posted by Jamestl

Hi all - really interesting thread. I'm a relatively new member and I've read quite abit but unsure on my three options for better shifting in this car. Trying to decide between the TRD short shifter, the clutch slave swap, and or the clutch spring removal. Anyone who has I'm done two or three of the above and can comment on the relative merit of doing them together? I'm not dissatisfied with the throws of the stock shifter, but the clutch feels very vague so that would be my priority. Thanks for any feedback!!

I don't see much value in a short shifter for this car, the throw is already really short compared to other cars I've driven or owned.

I did the slave swap and the spring adjustment (not removal or replacement). Doing those two things were enough to make me happy coming from driving a Boxster S previously. The spring adjustment wasn't enough, needed the new slave. The clutch won't feel as vague once you do the slave swap. The rest of it is just getting used to the clutch in this car.

Depending on how many miles you have on the car you might be getting close to needing a new TOB too if the clutch feels spongy. I'm at 31k and I'm getting close to not being able to stand it much longer.

[Jamestl]

Originally Posted by treminaor

I don't see much value in a short shifter for this car, the throw is already really short compared to other cars I've driven or owned.

I did the slave swap and the spring adjustment (not removal or replacement). Doing those two things were enough to make me happy coming from driving a Boxster S previously. The spring adjustment wasn't enough, needed the new slave. The clutch won't feel as vague once you do the slave swap. The rest of it is just getting used to the clutch in this car.

Depending on how many miles you have on the car you might be getting close to needing a new TOB too if the clutch feels spongy. I'm at 31k and I'm getting close to not being able to stand it much longer.

I've got about 80k on the new to me car. How does one tell if the ToB is about to go?

Also forgive me, what's the spring adjustment (vs removal)?

Thanks again!

[treminaor]

Originally Posted by Jamestl

I've got about 80k on the new to me car. How does one tell if the ToB is about to go?

Also forgive me, what's the spring adjustment (vs removal)?

Thanks again!

It might have been changed with regular maintenance already at 80k, do you have the service records?

From what i understand removing the spring makes the clutch extremely stiff and also slightly floppy at the top, adjusting it simply moves the grab point higher or lower. Replacing the spring with am aftermarket one makes it stiffer too but not as much as removal.

If the travel doesn't feel smooth then the TOB is on its way to going out. If you hear squealing it's already dead. Compare to a newer 86 if you can't tell

[Ultramaroon]

Originally Posted by treminaor

It might have been changed with regular maintenance already at 80k, do you have the service records?

From what i understand removing the spring makes the clutch extremely stiff and also slightly floppy at the top, adjusting it simply moves the grab point higher or lower. Replacing the spring with am aftermarket one makes it stiffer too but not as much as removal.

Meh, a little more stiff but not a deal breaker.

If the travel doesn't feel smooth then the TOB is on its way to going out. If you hear squealing it's already dead. Compare to a newer 86 if you can't tell

If the travel isn't smooth, it's because the TOB is hanging up on the snout. Although it's the same part, it's not the same as bearing failure. If you do your own work, and it hasn't been neglected for too long, might be able to get away with just clean and lube.

[inferno56kb]

Three questions.

Is it possible to reuse the crush washers when changing the slave cylinder? I'm not trying to cheap out here, it just seems to be impossible to translate crush washer into German and I also can't seem to find the dimensions of the original Subaru part anywhere so that i can get an aftermarket one, which leaves me to order them from Subaru themselves and I'm already pretty sure it'll cost more than i'm willing to pay for 2 gaskets. Haven't called them yet but my bet would be 5€ per piece at least.

Second, since i've been reading the last page. What is a TOB? I'm at 26k kms have no squealing and travel seems smooth, but all this talk of neglecting something I don't know about makes me uneasy ^^

Third, what kind of parameters does the grease need to have? Ultra said something somewhere (no time to look it up atm) that if you take the wrong grease and it mixes with the OEM stuff than it hardens and crumbles and that dirt would be trapped, or something along those lines iirc. It's almost certain I can't get the same kind of grease in Austria that you guys have over yonder so I need to find something that is similar to it (you can't imagine what a pain in the ass this is every time, for example I can't get most of the performance engine / transmission oils you guys have without paying double to tripple the price and importing them)

[ApexEight]

I used Honda Urea grease. Got it on Amazon. It's purpose is to grease clutch fork pivots and cups.

Did it last night but it's hard getting the grease right on the pivot. It was dusty and grimey but there was no way for me to clean it before applying new grease. Clutch feels great though and no signs of any squeaking or crunching that it was having before. Might just be because I greased the slave cylinder rod though. That thing was gunked up too.

To fully access the clutch fork and clean it and regrease it, you would have to drop the transmission, right?

Edit: Just saw the diagram above. I tried doing that but the pivot seemed tightly pressed against the cup so the best I could do was apply the grease above it and kinda on the shaft of the pivot. I might try this again today.

[Ultramaroon]

Originally Posted by inferno56kb

Three questions.

Is it possible to reuse the crush washers when changing the slave cylinder? I'm not trying to cheap out here, it just seems to be impossible to translate crush washer into German and I also can't seem to find the dimensions of the original Subaru part anywhere so that i can get an aftermarket one, which leaves me to order them from Subaru themselves and I'm already pretty sure it'll cost more than i'm willing to pay for 2 gaskets. Haven't called them yet but my bet would be 5€ per piece at least.

Second, since i've been reading the last page. What is a TOB? I'm at 26k kms have no squealing and travel seems smooth, but all this talk of neglecting something I don't know about makes me uneasy ^^

Third, what kind of parameters does the grease need to have? Ultra said something somewhere (no time to look it up atm) that if you take the wrong grease and it mixes with the OEM stuff than it hardens and crumbles and that dirt would be trapped, or something along those lines iirc. It's almost certain I can't get the same kind of grease in Austria that you guys have over yonder so I need to find something that is similar to it (you can't imagine what a pain in the ass this is every time, for example I can't get most of the performance engine / transmission oils you guys have without paying double to tripple the price and importing them)

I've had mixed results reusing them. Can't mash down too hard because the banjo fitting collapses. You can use standard 10mm copper gaskets. Very common.

TOB = ThrowOut Bearing = Clutch operate bearing.

I do make a big deal about not mixing greases because I have seen expensive, large-scale consequences in my professional experience.

Since first writing this, I have removed my transmission to clean and lube the whole clutch operating mechanism. I wouldn't worry too much about it because the grease that's already in there sucks. Just find one with a "lithium complex" suspension and you'll be fine. Unfortunately, there are bigger design issues in there. I have had a TOB and snout sitting on my coffee table the last several months that I occasionally play with while halfheartedly considering options. It's not just our cars that have the problem. Look at this. I don't care for their solution but they do a pretty good job of describing the issue.

[inferno56kb]

Originally Posted by Ultramaroon

I've had mixed results reusing them. Can't mash down too hard because the banjo fitting collapses. You can use standard 10mm copper gaskets. Very common.

TOB = ThrowOut Bearing = Clutch operate bearing.

I do make a big deal about not mixing greases because I have seen expensive, large-scale consequences in my professional experience.

Since first writing this, I have removed my transmission to clean and lube the whole clutch operating mechanism. I wouldn't worry too much about it because the grease that's already in there sucks. Just find one with a "lithium complex" suspension and you'll be fine. Unfortunately, there are bigger design issues in there. I have had a TOB and snout sitting on my coffee table the last several months that I occasionally play with while halfheartedly considering options. It's not just our cars that have the problem. Look at this. I don't care for their solution but they do a pretty good job of describing the issue.

Like just regular 10mm hole diameter flat copper gaskets? I thought the difference between those and the crush washers was that the crush washers are kinda conical around the hole and thus stop liquids better? If a regular 10mm flat copper gasket fits as well i can get those easily enough

Ah throwout bearing, alright i read a couple of things about that one already but didn't get the abbreviation. Will read your link too because i want to learn.

Alright, I will try to translate and find that kind of grease then, if that is the only thing that's important. I saw a post where only two possibilities were listed so i was kind of scared to put anything in there

thanks for your patience and tips, as someone that is only dabbling into mechanics this really helps a lot