Hydraulic clutch circuit sealant

[Paul Deslandes]

My external hydraulic clutch slave cylinder has developed a weep around where the hose coupling screws into the cylinder body. The thread is parallel not tapered so I don't think PTFE tape is the answer although I might be persuaded to give it a try. The mating surface of the cylinder is cylindrical (funnily enough) so a sealing washer of some sort won't work.

 

Is there a suitable sealant/thread lock that would do the trick? I suspect that's what was used previously and had lost its seal when I took the engine out recently.

 

Please don't tell me to revert to a cable, I don't want to

 

Thanks

 

Paul

 

[Jonathan Kay]

If you're sure it seals on the thread and not on an end surface (cone/ flare/ washer/ O-ring etc) what options do you have?

 

Loctite 542?

 

Usual platitudes about cleaning and inspecting.

 

Jonathan

 

 

 

Edited by - Jonathan Kay on 3 Aug 2014 21:24:15

[Paul Deslandes]

Hi Jonathan. Yes, it's definitely the thread as the coupling goes right through the cylinder sleeve. 542 is the only sealant I've found too, although I might consider an epoxy of some sort as that's what's been used to seal the bleed nipple adapter. If it was brakes I'd look for another solution but as the clutch is slightly less safety critical I can try a couple of options.

 

Paul

[Mavic82]

Paul,

 

I will check the number tomorrow night if you have not found a solution but I would try a loctite hydraulic sealant. Much like thread lock but specifically intended to seal threads against seeping fluids.

 

I use it on my dry sump fittings but equally at home on your nearest JCB.

 

 

Edit to add a quick google shows either 542 or 569. Can check which I use tomorrow.

Cheers

 

Guy

 

Edited by - Mavic82 on 3 Aug 2014 21:40:58

[Paul Deslandes]

Thanks Guy. Loctite 545 or 565 look to the right stuff although I suspect that even a small amount will be expensive. I might see if I can find the local Pirtek service man as he's bound to have something.

[Birkin S3 ZA.]

I always use Loctite 567 for sealing high pressure hydraulics 10,000 psi its very good and a bit thicker than the other products.

 

[Paul Deslandes]

The Pirtek man wasn't able to help so I decided, as it's clutch not brakes, to make a conformal nylon washer that follows the curve of the cylinder and apply the Loctite 243 that I use for normal thread locking/sealing applications.

 

It tested okay under heavy foot pressure so I remain optimistic 😬

 

Thanks for inputs

 

Paul

[Mavic82]

Ok, for reference I have just come in from the garage and I use 542.

 

Guy

[Paul Deslandes]

thanks for that Guy. If I get a repeat of the problem I'll have to buy a bottle.

 

Paul

[elie boone]

Didn't the original connection had a brass fitting ? this brass fitting would have been conical. If you tighten the connection make sure it isn't too long thus blocking the axe so it wont work properly.

[Paul Deslandes]

Unfortunately not Elie, the thread is parallel without any taper. My 'fix' using a thick nylon washer and standard Loctite 243 seems to be working so far.