Jump to content

Beware - not all bleed nipples are the same


Recommended Posts

Hi All,

I had gone just two miles on my first post restoration drive when it started to rain heavily so I turned round and headed home. When I looked at my brake fluid reservoir the fluid level had dropped by 5mm or so and was below the transfer hole between the two chambers. I soon traced the problem to the new (TRW?) bleed nipple fitted to a rear brake slave cylinder (original Girling). Fluid was weeping from the nipple which had been wound in extremely tightly with rounded corners on the hex section so I suspect there had been a problem getting it to seal. I removed the nipple and compared it to one from a Girling cylinder I had on the shelf and they are quite different in profile (see below). The TRW? nipple on the left has a shallower taper and does not come to a point. I put the Girling nipple on, nipped it up normally, and all has been well since. The car was returned with a fresh MOT so I am disappointed this was not picked up at the MOT station. I apologise if this topic has been covered before but a quick search under bleed nipples didn't reveal it.

Regards

Les

Rear bleed nipples.JPG

Link to post
Share on other sites

Frustrating to see the difference between them, I'm guessing a new wheel cylinder has a different bore than the original and the bleed nipple fits that but they are not interchangeable.

Gareth

Link to post
Share on other sites
On 11/4/2021 at 3:05 PM, Les Pettitt said:

Hi All,

I had gone just two miles on my first post restoration drive when it started to rain heavily so I turned round and headed home. When I looked at my brake fluid reservoir the fluid level had dropped by 5mm or so and was below the transfer hole between the two chambers. I soon traced the problem to the new (TRW?) bleed nipple fitted to a rear brake slave cylinder (original Girling). Fluid was weeping from the nipple which had been wound in extremely tightly with rounded corners on the hex section so I suspect there had been a problem getting it to seal. I removed the nipple and compared it to one from a Girling cylinder I had on the shelf and they are quite different in profile (see below). The TRW? nipple on the left has a shallower taper and does not come to a point. I put the Girling nipple on, nipped it up normally, and all has been well since. The car was returned with a fresh MOT so I am disappointed this was not picked up at the MOT station. I apologise if this topic has been covered before but a quick search under bleed nipples didn't reveal it.

Regards

Les

Rear bleed nipples.JPG

Transfer hole ? Do you mean baffle plate to separate front from rear brakes 

Link to post
Share on other sites

Have to agree, rubbish parts, poor quality, similar problem. New nipple replacing an (original) rounded off one. Moss replacement from China, seized in the caliper and then sheared when I put a ring spanner on it, result, new caliper .........

Link to post
Share on other sites

This issue sounds like a good one for the PQI initiative. Is anyone who suffered from this planning to raise this formally to the PQI-team?

Let’s help to improve our parts.

Cheers,

Waldi

Link to post
Share on other sites

This is why I only ever fit brass bleed screws https://automec.co.uk/collections/fittings/products/brass-bleed-screws-unf

Yes I know theyre expensive but you dont get problems with them.

Stuart.

Link to post
Share on other sites
18 minutes ago, stuart said:

This is why I only ever fit brass bleed screws https://automec.co.uk/collections/fittings/products/brass-bleed-screws-unf

Yes I know theyre expensive but you dont get problems with them.

Stuart.

+1 for brass bleed nipples. Beware metric vs imperial though.

Nigel

Link to post
Share on other sites
4 minutes ago, Nigel Triumph said:

+1 for brass bleed nipples. Beware metric vs imperial though.

Nigel

Well obviously order whats correct for the calipers you have.

Stuart.

Link to post
Share on other sites
On 11/6/2021 at 10:32 AM, stuart said:

This is why I only ever fit brass bleed screws https://automec.co.uk/collections/fittings/products/brass-bleed-screws-unf

Yes I know theyre expensive but you dont get problems with them.

Stuart.

The only thing I have against brass is that it age hardens and I feel that would make it prone to shearing off. I would prefer s/s.

Bruce

Link to post
Share on other sites
1 hour ago, astontr6 said:

The only thing I have against brass is that it age hardens and I feel that would make it prone to shearing off. I would prefer s/s.

Bruce

Never had one sheer yet as they dont seize in place.

Stuart.

Link to post
Share on other sites
1 hour ago, BlueTR3A-5EKT said:

Can I refer you to the OP picture of failed nipples that also had a flat tip like these stainless ones unlike the correct pointed brass ones.

Stuart.

Link to post
Share on other sites
2 hours ago, stuart said:

Can I refer you to the OP picture of failed nipples that also had a flat tip like these stainless ones unlike the correct pointed brass ones.

Stuart.

Good point.  
I was waiting for someone to spot that Pike!

Link to post
Share on other sites

Yes Neil,

I mean the baffle plate. There is a slot maybe 5mm x 2mm that is 10 or so mm below the top of the baffle plate. The fluid sits about 3mm above this slot in normal times.

The master cylinder is a new TRW one. I had a look at my original (1973) master cylinder and there is no slot so must be something TRW introduced.

Regards

Les

Link to post
Share on other sites
  • 1 year later...

Hi!, in the past I have come across bleed nipples which have a dished end to compress a small ball bearing into the hole where the pointed bit goes. As long as you remember to remove the ball bearing, a pointed nipple will do the same job. I do have doubts that the less pointed one would be good enough....

Link to post
Share on other sites
On 11/6/2021 at 10:32 AM, stuart said:

This is why I only ever fit brass bleed screws https://automec.co.uk/collections/fittings/products/brass-bleed-screws-unf

Yes I know theyre expensive but you dont get problems with them.

Stuart.

I am always a bit dubious of screw fittings made from brass as brass age hardens then you have the problem of shearing off??

Bruce.

Link to post
Share on other sites
10 minutes ago, astontr6 said:

I am always a bit dubious of screw fittings made from brass as brass age hardens then you have the problem of shearing off??

Bruce.

Never had that problem in using them for about 40 yrs as opposed to steel ones seizing and breaking off regularly when theyve not been touched for the same amount of time.

Stuart.

Link to post
Share on other sites

These guys are uber helpful on the phone and really know their stuff. They even sent me some titanium bleed nipples when SS wasn't in stock at no extra cost.

https://www.frentech-uk.co.uk

Admittedly it was for a more modern car, but they do classics as well. You can even send them what you have and they'll match it.

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.