Slave Cylinder failed 2 days after full service - Linked?

Taiko

Hoping for a bit of help on this one from people who may know a bit more, as I'm definitely not a mechanical person! The car is a 2016 Hyundai i40 SE Nav Business Edition

On the 17th March, I took my car in for a full service at an independent garage I've used for over a decade. At the same time, they replaced rear brake pads as these were identified. Some of the items in the service are below

Evening of 19th March was the first I really drove it. I parked up for 30mins somewhere, and when I went to pull away again, the clutch pedal would not come back up, and had to push the car back into a parking space. This was around 12 miles from home, after a short bit of motorway driving.

This was then directly below the car.

The garage have finally looked at it today, and said the Slave Cylinder has gone. This needs the gearbox to be taken off to undertake the replacement, and I've been quoted a total of around £800 including labour.

My questions really are:

Is the service actions likely to have had any interaction with this? Both brakes/clutch are from the same reservoir, and I don't really understand the process.

The car appeared to drive without any issues prior to service. Do these things just go, or are there warning signs prior? If so, am I right in thinking this should have been picked up in the service, based on the screenshots above.

Does the quote seem reasonable?

Thanks,

Woodstok2000

Does their quote include replacing the master cylinder at the same time? Not a mechanic either, but this happened on an old car of mine and was advised to get both done.

I had no major warning signs, looking back the clutch was maybe a bit spongy/sticky beforehand, but nothing really noticeable.

Goudy

The slave cylinders on these are now buried in the gearboxes bell housing, it's integrated with the clutch release bearing, they are what's now called a CSC or concentric slave cylinder.

They are no longer a separate slave cylinder operating a fork that then moves the release bearing. So:

A. That's why the gearbox needs to come off to get at it. (I hope they replace the clutch and CSC together)

B. Unless they had the gearbox off at service (which I very much doubt) then I can't see how they might have damaged it.

Yes they might have added more fluid to the system when they did the brakes and they might share that fluid, but the system is hydraulic and should withstand massive pressures within. I can't see that causing any problems.

I would just put it down to the seals breaking down. These i40's are prone to lots of clutch hydraulic problems.

Mildly_Miffed

The service list shown does not include changing the brake fluid - which is the one thing that they might do which would affect the clutch hydraulics, since they use the same fluid reservoir. It's one extra bleed nipple, but often omitted.

It's entirely feasible that changing and bleeding through the clutch hydraulics can cause the master to fail - because of rust inside the bore damaging the seals when they run through a different part of the cylinder travel.

But the slave? No. The slave doesn't move when bleeding the fluid through, and couldn't move outside that normal range because of the actual clutch mechanics anyway.

And, no, there's not really anything else that can or would cause the clutch slave to fail just after a service. It's pure coincidence.

Taiko

Thanks all, just incredibly bad luck then and a few hundred to spend!

Lorian

Goudy already mentioned - Don't overlook the opportunity for a new clutch (and maybe dual mass flywheel) while it's apart (more £££)

Taiko

Just an update on this, but got the repair carried out and DM Flywheel completed on the 28th March, setting me back £1300.

15th April, car refused to start at home, which then turned out to be the starter motor. A neighbour who knows more about vehicles then me, whilst trying to help, noticed a lot of oil around the 4th injector. Cue another garage trip totalling £350 for just the motor & labour.