Hydraulic thread seal

[RobinTR6]

I've got a stainless Good ridge flexible hose to the clutch slave cylinder. Although I've ensured its a tight fit it weeps the odd drip of clutch fluid.Pipe is new as is slave cylinder. Can anyone recommend a thread seal that hopefully will halt my drip.Many thanks.

[RogerH]

Hi Robin,

the thread isn't the problem.

Surely the pipe is not seating correctly on the internal seat of the slave housing.

If you seal the thread the fluid may then come around the seat and then up the pipe/union hole.

 

Take it apart and have a look to see what is keeping it from seating.

 

Otherwise have you tried PTFE plumbers tape.

 

Roger

[RobinTR6]

Roger, OK mate I'll undo and take a peak. Its been dripping on the new drive so SWMBO isn't happy....

[Motorsport Mickey]

As Roger says the thread is only there to keep the two unions together, the seal should be established where the male pipe end mates with the female profiled area. If the fluid pushes past that area you will lose a small amount of actual clutch pedal travel and eventually as the fluid runs out the clutch use (admittedly a fairly long time). I have no problem with PTFE on the threads, I use it on all my hydraulic connections but purely to keep threads free from corrosion and dirt ingress.

 

Mick Richards

[AlanT]

There is most likely a burr or ding on the mating faces.

 

Inspect with eye-loupe and you will probably be amazed it seals at all.

 

If its the cylinder, you can recut the face using a counter-sink, with the CORRECT ANGLE.

Do it very lightly by hand.

Edited May 26, 2015 by AlanT

[Rob Salisbury]

Be careful using PTFE tape on these small union parts, the tape acts as a lubricant so it is easy to over-tighten and strip the threads, or break the part.

Cheers Rob

[Steve Priest]

I had the same problem when I replaced my slave cylinder and switched to a braided hose on my TR4. The hose didn't connect with the internal seat that Roger and Mickey mentioned. Looking on the Moss website, I noticed that it lists a copper washer between the hose and slave cylinder, item 118 in this link. If you look carefully it's also in the diagram:

 

http://www.moss-europe.co.uk/shop-by-model/triumph/tr2-4a/clutch-transmission-drivetrain/clutch-systems/girling-clutch-hydraulics-tr4-4a.html

 

So, this is what I fitted and it solved the problem. However it is odd as it does look as though it should seal on the seat. Or is this a difference between the TR4 and later cars as the washer is not shown for the 4A hose (item 120)?

 

Steve

Edited May 26, 2015 by Steve Priest