Appears my slave cylinder failed

[hahuang65]

So I pulled the engine and transmission tonight and opened it up.

I'm still trying to figure out what exactly is the issue, but it appears that the slave failed?

 

Also the slave wasn't fully tightened to the bellhousing.

 

See attached videos. The photos where I point is where there is residual brake fluid, they appear to be around the slave, but also at the fittings on top of the slave, so I guess it's possible it's from that.

 

I'm awaiting my dealer to give me further instructions on testing/diagnosing, but would love to hear what other people think as well.

 

Also, if there's a place that these slave cylinders are available to purchase, it would be nice to have that info in the back pocket as well.

 

Thanks!

 

@EdWills as requested, here are the photos and videos.

 

https://photos.app.goo.gl/XMQUmy3QQfmccsyx5

[hahuang65]

I wonder if I suffered the same issue as

 

As described by @MV8.

 

 

[MV8]

I assume you loosened the attaching screws to look for leaks. That is the wrong wrench for the fittings. You must use a flare wrench.

 Looks like you got the new guy in the shop at CAT. The HRB looks ok. I think you will find the leak is from the fittings where they enter the top of the HRB/slave (I see some debris there also). Need to check first. Obtain a metric flare wrench set (home depot, auto parts store, etc), retighten the screws, then use teflon/thread sealing tape on the fitting (wrapped in the direction that won't unwrap when the fitting is being installed) and reassemble. Do not over tighten the screws or the fitting. There is very little pressure on the fitting.  

You should be able to pour fluid into the external fitting where the hose connects, plug that with your thumb, then push the release bearing toward the transmission a few times. Clean the area first, then tuck a strip of clean, dry paper towel in around the fittings to make it easier to see if it leaks.

It looks to be an oem part for mazda/ford that you can buy locally if the threads are damaged.

Refill the pipe, thumb over the pipe, and push the release bearing to check for leaks. Do not pressurize the HRB to test if it leaks without the engine installed. It will break the HRB. If you want to test before putting the drivetrain completely back in the car, get it close enough for the hose to reach. You could buy a longer hose just for this purpose. Don't use air to test if not equipped to ensure no more than 1 psi is used.

[wemtd]

Ooh🫣 looks like a Ford mondeo annular cylinder (need to check my notes) not available in parts stores here.

If your caterham supplier doesn’t have it  Tom Carlin probably will.

[jbcollier]

If you are in there, replace it.  Have a good hard look at the clutch, engine rear main seal and tranny input seal.

[MV8]

https://www.ebay.com/itm/357526746380?_trkparms=amclksrc%3DITM%26aid%3D1110006%26algo%3DHOMESPLICE.SIM%26ao%3D1%26asc%3D291120%26meid%3Ded224d1b02804fc4aa0e3a43beed6f4b%26pid%3D101196%26rk%3D5%26rkt%3D12%26sd%3D142660159406%26itm%3D357526746380%26pmt%3D1%26noa%3D0%26pg%3D2332490%26algv%3DSimplAMLv11PairwiseFitmentPromotionV2WithCassiniQueryEmbRecallKatRecoFC%26brand%3DDorman&_trksid=p2332490.c101196.m2219&itmprp=cksum%3A357526746380ed224d1b02804fc4aa0e3a43beed6f4b|enc%3AAQAKAAABMJdFoF6PhPSacVi2w45e4t0cBN66PGCzM%2B915a7NYCJWQXJFAaVpwOHIB34lpQ%2BNZxpndldJq3zwUnV3KJhR8xgcskqTch11K%2FSNdXk7fFg7iPPzHiMxOYZ5azcqRoyiyHLqAcJrQue6vGJNumIppH9UD3dVlDxMnuGhbs%2BiHCUFK1ZFhd1OFI5tl1xwQ2mPQYwKMvQXwXFKtPfCTwQsnsDNyck2TyCIz%2Bt0nzGQ7TVgojvL1PldICxdQdNdvCtpz02AP5ewLX1Iviv6nTfEHHlqmUDZazHlhCdxNTh6RrDMtH%2BSqJziuGMv366Rk%2BQEhq%2Bzd%2B%2FSHAj8tWr%2F9XJxAUwwt%2Bm8yQdwb1kc9sJjSFcz%2FeOX1xRk3a%2B%2BxP7K2NHc3QqTi5OdkKrSKmuw%2BmITjd0%3D|ampid%3APL_CLK|clp%3A2332490&epid=11080016701&itmmeta=01K3V16YG0AFN4D8SK2WK1WW7K

[hahuang65]

@MV8

 

I need to do more testing. Thanks for the suggestions. I will probably try what you're saying, but I'm also awaiting my dealer's guidance since this is will be a warranty issue.

I had a flare nut wrench but it didn't fit around the fitting.

 

I've also found

 

https://www.beachmanracing.com/clutch-slave-cylinder-and-bearing-duratecsigma

 

and 

 

https://www.walmart.com/ip/Dorman-CS360062-Clutch-Slave-Cylinder-For-95-07-Contour-Cougar-Mondeo-Mystique-Fits-select-1995-2000-FORD-CONTOUR-1995-2000-MERCURY-MYSTIQUE/538630283

 

Given the huge range of pricing, I'm a little suspect about the quality of the Walmart piece... though it claims to be the same item as the one you posted.

[MV8]

It's not a quality thing. It's a knowledge thing. All the links may be to the same product from a single manufacturer. Also does not mean that any seller is deliberately overcharging. Walmart doesn't make car parts so don't let that stop you.

[hahuang65]

More photos and vid from today

 

https://photos.app.goo.gl/TrU2pvdg1K1JM4Mz7

 

When the slave was bolted in fully, I added some fluid...no leaks.

 

I loosened the bolts...leaks from below.

 

I took out the slave cylinder,and wiped it down. And topped it off... No leaks. 

 

Compressed it...still no leaks.

 

I've left it on a clean paper towel to see if it seeps.

 

But it's strange because when it was leaking,it was flowing quite quickly...not just seepage.

 

Any one have ideas what else I should test? 

[hahuang65]

1 hour ago, MV8 said:

It's not a quality thing. It's a knowledge thing. All the links may be to the same product from a single manufacturer. Also does not mean that any seller is deliberately overcharging. Walmart doesn't make car parts so don't let that stop you.

Yeah that makes sense. I assume Beachman gets them in from Caterham and has shipping and tariff costs factored in etc

[MV8]

You added fluid to the bleeder side then opened the bleeder for it to flow in. You can't see it, but the fluid level equalized with the clear hose inside the black hose that would go to the master. You'd need to add fluid to the black hose, close the bleeder, then thumb over the black hose, then squeeze the slave. I believe it would have leaked where the pipes screw into the slave but you've removed those now. It looks like you've cut the dust boot so you might as well replace the assembly. Do not remove or loosen the new slaves pipes and there should be no issue.

[hahuang65]

So it looks like the slave is indeed leaking or seeping. I took out both the bleed line and the clutch line...filled both sides with fluid...

 

No leaks from compression...left it on a clean paper towel and an hour later, there's a small puddle on the paper towel...also see it on the lower lip of the cylinder.

 

Also one of the videos shows that filling the line and then loosening the cylinder from the bellhousing for some reason made it leak also. But strange there

[7Westfield]

Just to be sure.....you are NOT using DOT 5 fluid?

[hahuang65]

@7Westfield DOT4. Never hurts to double check

 

[IamScotticus]

Even if you stop finding leaks, before putting it back in the car and reassembling,  you must do a full pressure test.

Get a long pressure hose to connect to the MC and bleed.

Then the slave in a vice or something to capture the piston and pressurize the slave outside of the bell housing.

 

Edited August 30 by IamScotticus

[hahuang65]

2 minutes ago, IamScotticus said:

Get a long pressure hose to connect to the MC and bleed.

Safe to assume if I just have the slave cylinder unmounted, I can just connect it to the master cylinder to pressure test? Or does it have to be mounted to the bellhousing? 

[Anthem]

6 hours ago, hahuang65 said:

Safe to assume if I just have the slave cylinder unmounted, I can just connect it to the master cylinder to pressure test? Or does it have to be mounted to the bellhousing? 

Yes, pretty much most hydraulics systems should be tested on bench before installations.

[jbcollier]

You need to clamp it so it can't extend.

 

I'm only going to say this one more time, replace the slave cylinder.  After that, on your own head be it.

[hahuang65]

9 minutes ago, jbcollier said:

You need to clamp it so it can't extend.

 

I'm only going to say this one more time, replace the slave cylinder.  After that, on your own head be it.

Yeah I'm waiting for some new parts.

 

What do you mean by clamp it so it can't extend?

Edited August 30 by hahuang65

[jbcollier]

If you pump on the pedal to "pressure test" it, it will simply extend, not build pressure.  Worse, it could over-extend and come apart.  I'm a retired 35 year mechanic.  I don't see any reason to pressure test.  Just a fit it and tighten the lines properly and it will be fine.