[techcoze]

Hello friends,

I have read everywhere that clutch master / slave cylinders are considered to be bad and candidate for replacement when there is oil leakage seen from them (or you notice clutch oil level going down).

Assume that one changes clutch oil regularly (at interval of 2 years e.g., so this nullifies case of moisture in hydraulic system), can there be other situations when clutch master / slave cylinder would go bad without visible oil leak symptoms. Have anyone experienced cylinder failure without oil leakage?

My understanding of clutch hydraulics suggest that clutch would go bad only when there is leak & no moisture in system. Can experts confirm this please?

[RajeVenu]

Originally Posted by techcoze

Hello friends,

I have read everywhere that clutch master / slave cylinders are considered to be bad and candidate for replacement when there is oil leakage seen from them (or you notice clutch oil level going down).

Assume that one changes clutch oil regularly (at interval of 2 years e.g., so this nullifies case of moisture in hydraulic system), can there be other situations when clutch master / slave cylinder would go bad without visible oil leak symptoms. Have anyone experienced cylinder failure without oil leakage?

My understanding of clutch hydraulics suggest that clutch would go bad only when there is leak & no moisture in system. Can experts confirm this please?

All hydraulic systems are closed loop systems barring a few which are for special purposes, so even if you don't change the fluid regularly it cannot absorb moisture. There is performance depreciation due to breakdown of various components of the oil after a few years but not much for your clutch to fail.

Yes master cylinders can fail without leakage, the clutch master cylinder has a piston inside and there are separate channels for hi-pressure line and return(low pressure) line and their location in the cylinder differs for manufacturers. There are chances of hi-pressure leaking onto return lines due to defects/worn out seals or components. In these cases there will not be any visible oil leaks but your system will not work. Good service centres will have gauges/setups to measure clutch/brake master cylinder efficiency, you can check your cylinder for confirmation.
Alternately there are few cars in the market which use vacuum or air pressure for clutch/brake assist, in these systems there are hoses which connect to the cylinder and may leak making them ineffective. Hope this helps.

[KMT]

Yes if the service station drains fluid and pumps the pedal, the bore of the piston gets scratched. It happened to me.
No external evidence but took some detective work to figure out what happened..

[Jeroen]

Originally Posted by KMT

Yes if the service station drains fluid and pumps the pedal, the bore of the piston gets scratched. It happened to me.
No external evidence but took some detective work to figure out what happened..

This is something that is more likely to happen with brake systems then with clutch systems. On a clutch we always use (well you should anyway) full travel. You push the pedal to the stop. On the brakes system this is not the case. Which means that wear and tear and accumulation of dirt happens wherever the piston stops in the cilinder. When de-airing the system by pumping the pedal you push the piston (and thus its seals) through this patch of wear and tear / dirt.

So it’s better to use a pressure of vacuum system to flush and de-air the system.
Over the years I have seen several mlastercilinders fail due to this. Some brands/types appear to be very susceptible to it. Others not at all.

Jeroen

[rajivxing]

Hi guys,

I am excited about my 1st post on Team-BHP!

I own a 2011 model Mahindra Scorpio SLE. I live and normally drive in Delhi. A few days back, it's clutch pedal hit the floor and would not come up. The clutch system conked off. It came as a big shock to me. Luckily the car was on the side of the road and I stopped the vehicle.

I have faced the legendary clutch system failure of the Scorpio in Dharmshala some years ago. So I know that one can expect the clutch system to give way anytime in this vehicle. I opened the bonnet to check Clutch oil level. It was absolutely fine. Went under the car to check for clutch oil leakage from the slave cylinder. The underside is absolutely dry.

I came into the car and with my hand pulled up the clutch pedal. It came up. I pushed it down and it was responding. It began behaving fine as though nothing happened. Now I was worried. What could have made the pedal floor like this? Will it happen again? I am now fairly paranoid to take the car on the road.

Could anyone explain what could have made the clutch pedal behave the way it did? What should be checked? The clutch is behaving fine and gear shifting is normal.

Thanks for your help.

Rajeev Singh.

[TrackDay]

Originally Posted by rajivxing

I own a 2011 model Mahindra Scorpio SLE.
I opened the bonnet to check Clutch oil level. It was absolutely fine. Went under the car to check for clutch oil leakage from the slave cylinder. The underside is absolutely dry.

Even if there is no external leak, slave cylinders can go bad internally. Here is another thread on a similar line:
https://www.team-bhp.com/forum/techn...hout-leak.html (Can the clutch master/slave cylinder fail without a leak?)

https://www.youtube.com/watch?v=aAPB5IXrnNM

Since the vehicle is 10 years old, why not change the part ? Get it done by the service center or FNG who knows the job

[911CarerraS]

As Trackday said You should take your car to FNG and get it changed.
He may also suggest ways to repair it , there's only so much diagnosis that can be done online without having a looking at the car!

[vikasshu]

What to do if this ever happens on a highway? Is there anything that can be done or you need to wait for a mechanic?

I also own a Scorpio - 2015 Model (S 10).

Thanks

[mjkaushal]

Originally Posted by TrackDay

Even if there is no external leak, slave cylinders can go bad internally. Here is another thread on a similar line:
https://www.team-bhp.com/forum/techn...hout-leak.html (Can the clutch master/slave cylinder fail without a leak?)

https://www.Youtube.com/watch?v=aAPB5IXrnNM

Since the vehicle is 10 years old, why not change the part ? Get it done by the service center or FNG who knows the job

Thanks for the informative post.
I too am facing a similar issue. I have a Getz CRDI 2009 model which started to have some problems with the slotting of the reverse gear from last week. It kind of makes grinding noise and also difficult to shift to 1st , 2nd & 3rd gears.
The FNG guy is now suspecting the failure of the master and the slave cylinder which according to him should solve the problem failing which, the clutch assembly also to be replaced.

Being a Hyundai, the master and the slave cylinder assemblies are costing nearly 9000 and the clutch around 14000..

Could you please help me decipher the problem so that, I am not forced to replace parts which are not required.
The clutch pedal is a bit hard and there's absolutely no loss of power, mileage or stalling whatso ever.

I still get a healthy mileage of about 18 kms / Ltr of diesel. Would this change of master / slave cylinder solve the problem ??

Thanks & Regards,

[saket77]

Short answer: yes. The clutch cylinder on my Civic failed, thankfully while getting the car serviced at the Honda service Center. The clutch pedal sank while changing the fluid and bleeding the clutch. There was no leakage. The culprit was a broken push back spring inside the cylinder. It was replaced then and there.

[manjubp]

Yes it can fail. The master cylinder of our Getz car failed while driving. However after allowing it to cool for 30 minutes, we are able to use the clutch and drive the car to HASS.
HASS quoted 30K+labour+tax for full replacement of master/slave cylinder, clutch and release bearings. Just brought the car back without any work.

However Bosch service center was able to do the same with OEM parts for 18K and normal service, breakpad and other fluid replacements for another 6.5K.