jrhack None
Sept. 15, 2013 12:57 p.m.

My clutch pedal all of a sudden lost pressure and couldn't be shifted. I was told this was a hydraulic issue and to check the reservoir and slave cylinder. I have hydraulic fluid in the reservoir but it is really dark. The slave cylinder appears to be normal and dry. I applied pressure to the boot on the slave and no fluid was visible. I had my son press the clutch in and the piston only moves the clutch fingers about 1/4 to 1/2 inch. I opened the bleed valve and had my son press the clutch. Fluid was eject with pressure. I tightened the bleed valve back and then had him release the clutch. Do this indicate a bad slave valve? I was told when the slave valve goes, it is usually leaking somewhere. Any advise or help would be most welcome.

Knurled UberDork
Sept. 15, 2013 1:17 p.m.

What kinda car?

You should be able to see the backside of the master cylinder from under the dash. If it has fluid drooling out the back, then you need the master cylinder.

Good idea to replace the slave at the same time, as they usually fail in pairs.

jrhack New Reader
Sept. 15, 2013 1:58 p.m.

I have a 1996 Mazda Miata with six speed manual trans. I don't have any visable leakage.

Kenny_McCormic SuperDork
Sept. 15, 2013 2:25 p.m.

Probably master, replace both, they're cheap.

Knurled UberDork
Sept. 15, 2013 3:38 p.m.

Given that the master cylinders in RX-7s last about two years and that the Miata is 80% RX-7 I'd say it needs a master.

Even before you figure that the slave is not leaking and the hydraulics aren't doing anything (which ALSO says master).

What probably happened is the bore rusted/corroded in the master and it is bypassing. Very very common. That'll teach you to not flush the hydraulics every year.

jrhack New Reader
Sept. 15, 2013 8:17 p.m.

Well I went to the parts store (Auto Zone) and bought both the Master and Slave Cylinders (they were $20 each). I decided to put the Master Cylinder in first, mainly because there were no leaks at the Slave Cylinder. Upon putting the new Master Cylinder in and filling and bleeding the line, the clutch is working normally now. I will keep the Slave Cylinder for now and see if it acts up in the short term.

Kenny_McCormic SuperDork
Sept. 15, 2013 11:18 p.m.

Best to change both at once, cuts down on cross contamination and such.

You'll need to log in to post.

Also on Grassroots Motorsports

From the GRM Vault: Subaru Bounces Back

15 hours ago in Articles

Proof that motorsports involvement can lead to corporate success.

Your Projects: SkinnyG's V8 Pontiac Firefly

15 hours ago in News

Talk about a sleeper.

Calling All LS-Powered Track Machines to Holley LS Fest

16 hours ago in News

Holley LS Fest will once again feature the Grassroots Motorsports Road Course Challenge.

From the GRM Vault: A Dual-Engine Honda CRX and 10 Other Cool Cars Hit the Dyno

1 day ago in Articles

Back in 1997 we put 11 cool cars on the dyno in search of horsepower and truth.

You Need This: Our Mustang GT CAM-C Project Car

1 day ago in News

Soon for sale: Our Mustang GT autocross project.

Deal of the Month: Christmas in July!

1 day ago in News

Get a year of our magazine for just $10.

Your Projects: Smith College's $2017 Challenge Miata

1 day ago in News

Smith College is entering the Grassroots Motorsports $2017 Challenge

Big News From Mazda's Prototype Racing Effort

2 days ago in News

This just in: Mazda's prototype racing effort is changing hands.

Grassroots Motorsports LIVE! on Wednesday, July 19: Track Prep Your Daily Plus a Look at the Only Stick Shift GT3 RS

2 days ago in News

Tune in as we discuss pre-event inspection and prep. Also, a special appearance by a very cool Porsche.

Project Ridgeline Tows Home Another Project

2 days ago in Project Cars

We may or may not have gotten sidetracked on our Smoky Mountain Tour.

You Need This: Supercharged Toyota MR2

3 days ago in News

Rebuilt engine? Check. Extra power? Check. Early MR2 cool factor? Double check.

2017 Volvo V90 Cross Country T6 AWD

3 days ago in New Car Reviews

We're keeping the all-wheel-drive wagon theme rolling. We reviewed the Subaru Impreza last week and the Volkswagen Golf SportWagen before ...


Grassroots Motorsports Magazine

Subscribe Today

Also get your instant access to the digital edition of Grassroots Motorsports Magazine!

Learn More