Possible Slave cylinder problem? Thoughts

OzGuvnor · Postby **OzGuvnor** » Fri Oct 31, 2014 11:28 pm

From reading the forums I think I may have a slave cylinder problem??? (1997 NA8)

First gear quickly became unusable over 15 kms, forcing me to start from 2nd. Also 2nd & 3rd were grindy to change. Nothing like normal. It was difficult to get it into 2nd from neutral at a standstill too. I found it easier to double clutch slowing down into 2nd and then hold the clutch in with the gear in 2nd at the red lights. Third felt terrible and Melbourne traffic near the city at 5pm on a Friday didn't allow me any higher gears :-p

At first I thought it was a worn clutch, except it wasn't slipping struggling for power. I was always under the impression that once the clutch plate is worn out that the power just doesnt get through. From reading it seems like it might be the slave cylinder issue I read about.

I replaced the gearbox oil about 3000 kms ago, so its not like its done much on the oil. The car is has only done 124K kms

Is what I am experiencing sound like this issue?

JBT · Postby **JBT** » Fri Oct 31, 2014 11:56 pm

Quite possibly a hydraulics problem - slave or master.
Have you checked the fluid level and checked for leaks?
When was the last hydraulic oil (brake and clutch) flush?

OzGuvnor · Postby **OzGuvnor** » Sat Nov 01, 2014 12:01 am

I had it serviced and tuned by the MX5 Factory in Bayswater (VIC) and at the time I asked them to change the fluid - which was 12 months ago.

That said I hadn't checked the fluid levels recently. I will do that tomorrow. It was the first hot day I have dríven in today in a while (31) too.

If the levels are low could it be worth bleeding the system first? (Before replacing components).

At least this didn't happen in just under a month when i plan on being on the track at Sandown.

93_Clubman · Postby **93_Clubman** » Sat Nov 01, 2014 12:11 am

Yeah, sounds like slave cylinder. Recently replaced mine after first replacing it in 2004. Noticed the cylinder end of the rubber boot looked damp, & sure enough there was a bit of fluid inside the boot.

https://www.sparespro.com.au/PROTEX-S-C ... B4225.html

project.r.racing · Postby **project.r.racing** » Sat Nov 01, 2014 9:15 am

Visual inspection should come before keystrokes.

OzGuvnor · Postby **OzGuvnor** » Sat Nov 01, 2014 11:43 am

Couldn't agree more speed racer. What am I looking for in a failed clutch master or slave?

Bearing in mind I am a first timer looking at this. Willing to learn and have a go though.

JBT · Postby **JBT** » Sat Nov 01, 2014 12:22 pm

Master cylinder may leak into the floor area - look for oily carpet or wetness on the rod from the clutch pedal.
Slave cylinder will leak rearward - check for oil in the rubber boot on the clutch release rod (comes out the back of the slave).

manga_blue · Postby **manga_blue** » Sat Nov 01, 2014 2:43 pm

As they said, it could be slave cylinder or master cylinder or both. Visual inspection for leaks doesn't always show anything, even when they're stuffed. It's age and infrequent fluid changes that wreck clutch and brake cylinders, not mileage. Realistically yours are 20 years old. Most of us have replaced the clutch slave and master at least once by now.

Alternatively there's a possible mechanical cause to your problem. The gearbox spigot bearing may be seized. That's a small bearing where the front of the gearbox input shaft fits into the engine flywheel. It's gearbox out to replace it and that becomes a can of worms because it may well reveal a worn clutch and a leaking rear main engine seal as well. These are most economically replaced at the same time.

I'd find a recommendation for a good generic brake and clutch service guy near you and take it there. If you don't know one then Dean Brooking at Motorsport Essentials in Mulgrave knows MX5s and could sort this out.

OzGuvnor · Postby **OzGuvnor** » Sat Nov 01, 2014 2:54 pm

I peeled back the rubber boot of the master slave just a tiny bit as you mentioned and fluid leaked out immediately. Off to Repco.

trader · Postby **trader** » Sat Nov 01, 2014 4:07 pm

I'd be looking at the slave cylinder also and changing it anyway. If you're really keen go for the direct hydraulic line between the two.

OzGuvnor · Postby **OzGuvnor** » Sun Nov 02, 2014 8:20 pm

Job done this afternoon. Removal was straightforward. The piston in the slave was clearly leaking. I phoned friend to help with refitting and bleeding. It could have been done solo, but was easier with someone helping. The thing I noticed upon the test drive after finishing was that before whilst it was failing the bite point on the clutch had crept slowly but surely towards the firewall without me really noticing. It is biting significantly further out now. Much better.

Thanks to the forum members for your input. This forum, combined with YouTube, makes it possible for us non-mechanics to have a go and learn.

Vat · Postby **Vat** » Sun Nov 02, 2014 10:25 pm

OzGuvnor wrote:From reading the forums I think I may have a slave cylinder problem??? (1997 NA8)...

At first I thought it was a worn clutch, except it wasn't slipping struggling for power. I was always under the impression that once the clutch plate is worn out that the power just doesnt get through. From reading it seems like it might be the slave cylinder issue I read about.

Is what I am experiencing sound like this issue?

Yeah, sounds like it. My trick is always to stick it in 5th at about 30 or 40 and stand on it. If the clutch is slipping that will show it. I had similar symptoms to what you described with the Jaffa during its test drive and I took a punt, turned out to be a master cylinder.