slave bleed nipple

bubs · 21st November 2013, 12:12

Is there any way that the bleed nipple connector on the slave cylinder can come loose? The connector does spin around the pipe but there's no way to tighten it up.

I have an LUK freelander slave fitted and air is getting in the system somehow and collects right next to the bleed nipple, I don't seem to be losing fluid so I can only think that the nipple is sucking air in when the clutch pedal comes back up, but is that even possible without fluid going out somewhere?

DMGRS · 21st November 2013, 12:15

They're usually press-fitted (or in the case of plastic pipe versions, heat shrinked) on to the end of the pipe. If it's spinning, it could be letting air in - however unless it's a very small leak I'd expect to see a little bit of fluid there too.

Could be a case for an epoxy resin such as JB Weld - that stuff is ridiculously strong, and as far as I know resistant to brake fluid too.

bubs · 21st November 2013, 12:26

It's not spinning loosely but can be turned round on the pipe, i tried tightening the nipple up as much as possible but that didn't help. As you said i would have thought air in means fluid has come out. I was just clutching (no pun intended) at straws really in the hope it isn't the slave cylinder itself that needs doing again.

DMGRS · 21st November 2013, 12:32

I'd say Master, however the air wouldn't make it down towards the slave unless it was leaking a lot (you'd be topping up a lot, and also noticing the fluid under the car).

The issue is, there's never any negative pressure in the system. When you let go of the clutch pedal, the springs of the clutch push the slave back to it's 'compressed' state, meaning there is still positive pressure in the pipework. This wouldn't allow air in at the bleed nipple - it'd cause a leak externally of fluid.

Any fluid leaking out of the system will be replaced by more fluid from the master, until this supply is extinguished. Then air will be pulled in via the master cylinder.

bubs · 21st November 2013, 13:06

Makes sense. I did replace the master (which looks like it was weeping from around the plunger) with the old spare one I had but i'm still getting air from the slave end. It only takes a quick open of the bleed nipple which releases mostly air to get the pedal back up before it sinks again over a few days. I only filled the master up before fitting so could the air have got trapped in the old slave and worked it's way round? Surely if that was the case after bleeding a few times the air would all be out by now.

Maybe I should bleed the system fully again and see what happens.

bubs · 2nd December 2013, 06:33

I've fully bled the system again and it's still dropping. I'm more or less certain it's the slave connector/nipple causing it. I made sure it was completely clean when i bled the system and when the pedal sank again I checked the connector first and it had fluid around it so it looks like it's leaking and sucking air in.

Any ideas if it's possible to tighten it up?

DMGRS · 2nd December 2013, 08:41

See my 2nd post in this thread...

Usually the answer is no as they're press fitted.
I still think some very strong epoxy will be worth a shot.

bubs · 2nd December 2013, 09:04

Wouldn't that block it up though, should i need it again i'd be stuffed?

dissy1810 · 2nd December 2013, 09:05

I have heard of this happening before, the lad that had the problem got an old slave, cut off the bleed nipple with a small length of pipe then cut off the one on the car and attached the good one using a compression fitting

DMGRS · 2nd December 2013, 09:07

Quote:

Originally Posted by bubs

Wouldn't that block it up though, should i need it again i'd be stuffed?

Not the way I'd do it - I was thinking make a 'sleeve' of epoxy around the pipe, leading up to where the union joins it. Just make sure you have a good, thick layer, and when it hardens it'll seal the joint.

Compression fitting is also a good idea.

21st November 2013, 12:12	#1
bubs Posted a thing or two ROVER 75 Join Date: Oct 2012 Location: Canvey Island, Essex Posts: 1,651 Thanks: 43 Thanked 163 Times in 134 Posts	slave bleed nipple Is there any way that the bleed nipple connector on the slave cylinder can come loose? The connector does spin around the pipe but there's no way to tighten it up. I have an LUK freelander slave fitted and air is getting in the system somehow and collects right next to the bleed nipple, I don't seem to be losing fluid so I can only think that the nipple is sucking air in when the clutch pedal comes back up, but is that even possible without fluid going out somewhere?

21st November 2013, 12:15	#2
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,354 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	They're usually press-fitted (or in the case of plastic pipe versions, heat shrinked) on to the end of the pipe. If it's spinning, it could be letting air in - however unless it's a very small leak I'd expect to see a little bit of fluid there too. Could be a case for an epoxy resin such as JB Weld - that stuff is ridiculously strong, and as far as I know resistant to brake fluid too. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

21st November 2013, 12:32	#4
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,354 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	I'd say Master, however the air wouldn't make it down towards the slave unless it was leaking a lot (you'd be topping up a lot, and also noticing the fluid under the car). The issue is, there's never any negative pressure in the system. When you let go of the clutch pedal, the springs of the clutch push the slave back to it's 'compressed' state, meaning there is still positive pressure in the pipework. This wouldn't allow air in at the bleed nipple - it'd cause a leak externally of fluid. Any fluid leaking out of the system will be replaced by more fluid from the master, until this supply is extinguished. Then air will be pulled in via the master cylinder. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

2nd December 2013, 08:41	#7
DMGRS Discount MG Rover Spares Rover 75 CDTi, 2x MG ZS180 Join Date: Jun 2011 Location: Hythe, Southampton Posts: 11,354 Thanks: 456 Thanked 3,377 Times in 2,027 Posts	See my 2nd post in this thread... Usually the answer is no as they're press fitted. I still think some very strong epoxy will be worth a shot. __________________ Your trusted MG Rover specialist! Tel: 02380 001133 / Email: [email protected] We now have a 'chat' function on our site for even quicker replies. Give it a try! Remember - discount code FORUM5 for 5% off

2nd December 2013, 09:05	#9
dissy1810 Posted a thing or two mgzt 160 1.8 lpg Join Date: Mar 2010 Location: newcastle upon tyne Posts: 1,973 Thanks: 5 Thanked 72 Times in 64 Posts	I have heard of this happening before, the lad that had the problem got an old slave, cut off the bleed nipple with a small length of pipe then cut off the one on the car and attached the good one using a compression fitting __________________ http://i1030.photobucket.com/albums/...0/Photo389.jpg

21st November 2013, 12:26	#3
bubs Posted a thing or two ROVER 75 Join Date: Oct 2012 Location: Canvey Island, Essex Posts: 1,651 Thanks: 43 Thanked 163 Times in 134 Posts	It's not spinning loosely but can be turned round on the pipe, i tried tightening the nipple up as much as possible but that didn't help. As you said i would have thought air in means fluid has come out. I was just clutching (no pun intended) at straws really in the hope it isn't the slave cylinder itself that needs doing again.

21st November 2013, 13:06	#5
bubs Posted a thing or two ROVER 75 Join Date: Oct 2012 Location: Canvey Island, Essex Posts: 1,651 Thanks: 43 Thanked 163 Times in 134 Posts	Makes sense. I did replace the master (which looks like it was weeping from around the plunger) with the old spare one I had but i'm still getting air from the slave end. It only takes a quick open of the bleed nipple which releases mostly air to get the pedal back up before it sinks again over a few days. I only filled the master up before fitting so could the air have got trapped in the old slave and worked it's way round? Surely if that was the case after bleeding a few times the air would all be out by now. Maybe I should bleed the system fully again and see what happens.

2nd December 2013, 06:33	#6
bubs Posted a thing or two ROVER 75 Join Date: Oct 2012 Location: Canvey Island, Essex Posts: 1,651 Thanks: 43 Thanked 163 Times in 134 Posts	I've fully bled the system again and it's still dropping. I'm more or less certain it's the slave connector/nipple causing it. I made sure it was completely clean when i bled the system and when the pedal sank again I checked the connector first and it had fluid around it so it looks like it's leaking and sucking air in. Any ideas if it's possible to tighten it up?

2nd December 2013, 09:04	#8
bubs Posted a thing or two ROVER 75 Join Date: Oct 2012 Location: Canvey Island, Essex Posts: 1,651 Thanks: 43 Thanked 163 Times in 134 Posts	Wouldn't that block it up though, should i need it again i'd be stuffed?