Slave cylinder hose gasket?

[78sid]

I've got a leak that on the hydraulic hose mating to my clutch slave cylinder. It appears to be metal on metal. Should there be a gasket of some sorts? Seem obvious, but I wanted to make sure I'm not missing something else.

Thanks.

Edited March 18, 2013 by 78sid

[LeonV]

Nope.

[78sid]

Nope.

Thanks. Saw a post on zcar.com about using a brass crush washer. Any thoughts?

[LeonV]

Sounds like the fitting is either undertorqued or overtorqued/damaged. Please don't use a washer/gasket to seal it.

[Zed Head]

The fitting on the slave cylinder is a straight thread, not a taper, (I just looked at my spare cylinder) with no seat for a flared tube end either. Seems like it would benefit from a washer unless they did some precise machining on the flat seating surfaces. Maybe the factory parts are of higher quality than aftermarket. My car came with a copper crush washer, although I don't know if it's stock. And good old carpartsmanual.com shows a washer, but, oddly, it's on the end of the hose that does have the typical brake line flare fitting.

Why the "please" on no washer?

Datsun 240Z/260Z/280Z Clutch Control Hose

and Nisan sells the hose washer

GASKET-HOS :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

[78sid]

I'm going give it a good torque and see if it is dry in the morning. If it still leaks, I'll try a washer. If that doesn't work, I'll start over. Not a huge expense either way.

I'll update my results.

[LeonV]

The fitting on the slave cylinder is a straight thread, not a taper, (I just looked at my spare cylinder) with no seat for a flared tube end either. Seems like it would benefit from a washer unless they did some precise machining on the flat seating surfaces. Maybe the factory parts are of higher quality than aftermarket. My car came with a copper crush washer, although I don't know if it's stock. And good old carpartsmanual.com shows a washer, but, oddly, it's on the end of the hose that does have the typical brake line flare fitting.

Why the "please" on no washer?

Datsun 240Z/260Z/280Z Clutch Control Hose

and Nisan sells the hose washer

GASKET-HOS :: Nissan Parts, NISMO and Nissan Accessories - Courtesyparts.com

Because it shouldn't leak as designed, as you can see in the drawings that you provided. If it's leaking, something's wrong.

That other washer is very likely used for load distribution, NOT sealing pressurized hydraulic fluid.

[Zed Head]

Ah, the engineer's esthetic (no offense, I feel the same). Unfortunately for us, aftermarket parts are usually not as-designed. Just sayin', it's one of those realities.

Anyway, to the PO, you might check under the rubber boot for fluid. It might be the cylinder itself that is leaking.

[Darrel]

Every slave cylinder I have taken on and off used a copper crush washer to seal. Go to the hardware store and get one.

Looking through my factory manuals, '82 zx, '79 620 and '73 240z. The 620 manual shows a washer at the slave although it isn't named but can see it in an assembled drawing. The '73 doesn't show or say anything about the washer. Mine did have a copper washer and it was all stock.

The '82 zx service manual shows a washer for the slave and recommends use a new one when replacing parts.

Edited March 19, 2013 by Darrel
more info

[Captain Obvious]

I agree. The threads aren't tapered, there's no way I would want the steel shoulder of the hose end fitting trying to dig into and seal against the body of the slave cylinder. I think there's supposed to be a somewhat malleable washer in there.

As for that washer in the pic, I think it's a typo. I think they showed it at the wrong end of the hose. There's absolutely no reason for it where they have it shown. The end of the hose is held in place with the typical clip-in-groove, and the sealing is done by the flare on the end of the hard line.

The only thing a washer would do at that end is get in the way of the two flats on the hose fitting that are there to keep the hoes end from turning as you tighten the hard line. :bulb:

[Captain Obvious]

I found it. Page CL-9 of the 78 manual... Top right:

Install clutch hose on operating cylinder with a gasket in place. Note: Use new gasket.

(Or CL-8 of the 77 manual. I didn't look earlier than that, but I assume they're all the same.)

Edited March 19, 2013 by Captain Obvious

[78sid]

Thanks and good stuff guys. I'll take care of it tomorrow.