Yaris 2011 Clutch pedal problem (1NR-FE 1.33 6 speed engine)

[Mark_C]

Hi all,

Our Yaris is now off the road having developed a clutch problem whereby the clutch pedal feels really light to press down and the gears will no longer engage. Prior to this there have been no issues with the clutch whatsoever, this issue seems to have happened very suddenly on one car ride back home when I started noticing a weird change in the clutch pedal and I was struggling to get in to gear. Luckily managed to get back on to the driveway before the gears completely crapped out!

I have bled the clutch/brake fluid and air bubbles come out with what looks to be a dark gritty looking fluid - not good at all. After doing this, resistance returns back to the pedal and I can then shift normally again but after a week it just goes back to how it was and the process requires repeating again so evidently there's something wrong.

Doing research it could be the master or slave cylinder, except this model seems to have no slave cylinder?? Looks like it hosts something called a CSC that acts like a slave cylinder? Any clues on what I should be looking out for? I can't find any service manuals for this specific version of the car, only the older 2006-2008 car with what looks like the old classic external slave cylinder. Any help would be most appreciated.

 

TIA,

Mark

 

 

 

[flash22]

CSC stands for Concentric Slave Cylinder - are you loosing brake fluid, note, there is a divider in the master res if you don't keep it slightly over full the clutch side does not refill

 

[Cyker]

The CSC is basically a slave cylinder combined with a release bearing, and if it hasn't been changed for a long time the rubber seal that lets it move in and out may have degraded. Do you know when the clutch was last done? If it was changed without changing the CSC it could be worn.

As flash says, check the hydraulic reservoir first tho'. Maybe see if there is any evidence of drips or fluid under the car too.

[Mark_C]

Thanks for the responses! From what I've seen so far, I don't appear to be losing brake fluid. I noticed that the fluid level in the reservoir was exactly on full so I've filled it to just a bit above that. I'll keep an eye on the fluid level and see if it moves from where it was. I've bled it again and finally managed to get stiffness back to the pedal but I have a feeling after leaving it it'll just go back to how it was. 😞 

Regarding the clutch age, as far as I'm aware I don't think it has ever been replaced since the car was bought when it was second hand in 2013. It only has 45000 miles on the clock so hasn't had a hard life.

[flash22]

I would suspect the clutch master has failed, no pressure and no fluid loss is a failed seal

[Stevie J]

The Clutch runs from the same fluid reservoir as the brakes, which is mounted on the brake servo unit. If this reservoir is anything like the Mk2, it has 2 separate compartments within it, and the clutch reservoir is at the back of the main reservoir. I think they do this so that if the clutch line loses fluid, the brakes side of the reservoir wont then also run dry. When you look at the reservoir from the front, it actually looks full, so you can be fooled into thinking the clutch has plenty of fluid, but in reality, the rear part of the reservoir could be empty. There is a divider in the main reservoir that comes almost to the top, and the brake fluid has to be full before it overflows into the side for the clutch system at the rear of the reservoir. I found that out when I was trying to bleed the clutch on my old Mk2, to try to get the biting point to be higher than about an inch off the carpet. If the rear part of the reservoir is not kept full, it can empty during the bleed process and introduce more air into the clutch master and slave.

2011 was the year the Mk3 came out and also could be the end of the Mk2 run, ie, you could get both the mk2 and mk3 in that year, but as the late model Mk2 (2009 - 2011) had the 1.33 6 speed box, I imaging that it has the same setup as the Mk3, which is the clutch slave is concentric and the only way to change it or get to it is to remove the gearbox from the engine. If the slave has been leaking it could well have contaminated the clutch linings.

I'd imagine the first port of call would be to replace the master cylinder behind the clutch pedal first, as this would be cheaper to do, and if this doesnt work, then there would be no other option than to have to get the gearbox off to get to the concentric slave / thrust bearing, and if that was going to be done, it would make sense to replace the clutch as well.

[Fleckens]

On 7/12/2023 at 11:54 AM, flash22 said:

I would suspect the clutch master has failed, no pressure and no fluid loss is a failed seal

Hi, hope someone will still respond to this old thread as I have a the same issue on a low mileage 2016 car, clutch never changed. 

I have the exact symptoms as the OP. No fluid loss and after pumping the clutch for a min the clutch engages, never gets as firm as it should but at least changes gears.

I also found that if the clutch pedal is depressed very slightly a few times, before it feels firm it would lose pressure very quickly. In my mind suggesting some kind of air leak at the top end of the master cylinder which fits with what flash said above. 

I had a local mechanic, whom I trust, look into it to confirm my suspicions. He bled the system and no matter what he tried the air would come back. He suggested the master should be changed first as it's a relatively easy job, and if that failed, open up the gear box and change the csc cylinder and clutch for sake of it.

Now the fun bit, this car has always been serviced at Toyota so is covered by their 'Relax' warranty, so I figured I should take it to Toyota as both the master and csc slave clutch cylinders are explicitly covered in the warranty terms. 

The car was booked in and on the morning I dropped it off, I had to pump the clutch a few times and it went into gear, I drove it to the dealer explained everything above. Later that day I get call to say they need to take out the gear box and that i need to agree up front to to 5 hours labour incase it turns out to be something not covered like a busted pipe. Apparently, they've had it in the workshop and its leaking fluid so it could be the pipe. This is very strange as it's never leaked on my drive and I'd previously looked under the car and it was dry. So I drove down there in our second car to see the leak for myself. The car is in the same spot I left it, I look under the car and the theres a pool of brake fluid on the ground, strangely the very bottom of the gearbox is still dry. 

Not sure what's going on here but I suspect I'm being taken for a ride and the dealer is trying to wiggle out of the warranty repair, they want me to pre-agree to labour costs should the faulty item not fall under the warranty. 

As I understand it other than the CSC cylinder there is only a small pipe inside the gear box which connects the CSC to the housing and this never fails according to my local mechanic. 

I really don't understand why they don't want to change the master cylinder first. I've not agreed to the work yet and considering  picking up the car back and get the local mechanic change the master cylinder and take it from there. I guess I'll still be hit with Toyotas 'Diagnostics' cost but I'm happy to cut my losses than deal further with them. Problem now is the clutch is not operating at all as they probably loosened the bleed nut and let it leak out. 

Maybe I'm being paranoid but has anyone else had such an experience? 

OP can you please confirm your solution? 

Sorry for the long post but this has turned into a bit of a saga. 

Cheers

Fleck

 

 

 

[flash22]

It is either the master or slave, if CSC has over-extended due to a faulty pressure plate It is a gearbox out job while you are in there you are doing the clutch, 5 hours at £125 per is a whole lot of cash, clutch slave and master and the clutch are wear and tear items so will not be covered you may end up with a pelican of £1200-1800

for what you are going to spend at a dealer just diagnosing it is nearly the cost for a clutch job with a decent clutch like an LUK, the master is £100-150 on top

bite the bullet and get it sorted in one go at an independent

[Red_Corolla]

I don't know, but I would have thought it possible, with the appropriate fitting, to either confirm or refute a master cylinder fault by blanking the line at the point where it enters the bell housing. If the master and the line are good, that should result in a firm pedal. Similar logic to clamping off brake hoses at the wheel to locate a faulty wheel cylinder. Just an idea - perhaps it's not so easy.

[Fleckens]

55 minutes ago, flash22 said:

It is either the master or slave, if CSC has over-extended due to a faulty pressure plate It is a gearbox out job while you are in there you are doing the clutch, 5 hours at £125 per is a whole lot of cash, clutch slave and master and the clutch are wear and tear items so will not be covered you may end up with a pelican of £1200-1800

for what you are going to spend at a dealer just diagnosing it is nearly the cost for a clutch job with a decent clutch like an LUK, the master is £100-150 on top

bite the bullet and get it sorted in one go at an independent

Yes this is what I suspect will end up happening... I think me getting this sorted under the relax warranty is turning into a pipe dream, no pun! I think even if it is a leaking csc  there are too many other things they can blame. The local mechanic already did he would change the master for £150 first. 

The car is still at the dealers, I'll need to bleed the clutch on their forecourt to get it moving again. I'm sure they just let out the fluid just to show 'evidence' I have a leak. 

Thanks for your response.  

 

 

[Fleckens]

29 minutes ago, Red_Corolla said:

I don't know, but I would have thought it possible, with the appropriate fitting, to either confirm or refute a master cylinder fault by blanking the line at the point where it enters the bell housing. If the master and the line are good, that should result in a firm pedal. Similar logic to clamping off brake hoses at the wheel to locate a faulty wheel cylinder. Just an idea - perhaps it's not so easy.

I did think about this... Could be something I would try myself but I don't think my local indy would bother. He wants to change the master first, which to be honest I don't mind paying for. 

[Fleckens]

Quick update on this. It turned out to be the csc cylinder in the gearbox. The dealership did the repair under the relax warranty, phew. The clutch and plate was also replaced at parts only cost to me. 

 

Thanks all

 

[flash22]

well that saved you a few quid and you got a cheap(er) clutch job

[Cyker]

The CSC's covered by the warranty?!?!?!?   

[Fleckens]

Yeah it's actually specifically listed in the warranty terms. 

[Cyker]

That's cool, I assumed it would be classed as a wear part as it's basically a slave cylinder and release bearing mashed together, and the Toyota one is very expensive!