brake cylinder bleed nipples

DoubleChevron

DoubleChevron

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Hi Guys,

the traction here has only one brake cylinder with a bleed nipple. The rest are bleeders with a bolt into the back of them. They don't allow you to hook a bleed tube to them.

Does anyone know where I can get M11 x 1.25 bleed nipples from? (what I have will work, but is a PITA ). The bolt screwed into the back of what must be the factory bleeders (I'm guessing it acts as a dust/dirt cap) is M6 x 0.9 ....... And its a real citroen bolt with the citroen chevrons on it .... bizarre. I've never seen a M6 x 0.9mm citroen fastener before.

I'm guessing everyone just takes this bolt out and lets the brake fluid spray everywhere? (I was going to try a vacuum bleeder on it ... but obviously cant without nipples :) ).

seeya
Shane L.
 
Hi Shane, how confident are you of the accuracy of your thread measurements?

Is it possible that the threads are 7/16" BSF and 1/4" BSF ?
How is the plug bolt sealed into the bleeder body?
A pic would help.

Maybe...... if you drilled a 2mm hole almost through the plug , then one in the side of it.... you might simulate a proper bleed screw.

Is it anything like this?
20211017_114156.jpg
 
My '54 11BL had one of those bleed screws with a bolt threaded into another hollow bolt. I was able to find an SAE bleed nipple to replace the two, however, I failed to record what the thread size and pitch was, sorry.
 
I think I'll just leave them alone .... if Johns car had them, they must be still there from new. Amazingly I've changed the front soft lines without breaking anything. I expected to sheer everything off and have to replace all the lines back to the master cylinder ( heat and candle wax is an amazing thing on frozen fasteners).

20211017_123914.jpg


20211017_123951.jpg


20211017_124420.jpg


20211017_124531.jpg


See the tapered end, and the holes. Its a proper "bleeder". It just capped with an M6 x 0.9 bolt (rather than a bubble flare and plastic/rubber cap).

20211017_124558.jpg


20211017_124625.jpg


20211017_124724.jpg


This might be normal for pre-50's cars .... I've just never seen it before :) So there you go, if you ever find an M6 x 0.9 fastener with a Citroen head on it .... it belongs to a traction brake bleeder.

I'm sure Bob will know if M6 x 0.9 is an AF size .... :)

seeya
Shane L.
 
Shane, I have a set of Brass nipples that Dad made up years ago. I just screw them into the hole in the bleeder to bleed and then replace the original set screw afterward. You may borrow them if you wish!
 
gerrypro said:
Shane, I have a set of Brass nipples that Dad made up years ago. I just screw them into the hole in the bleeder to bleed and then replace the original set screw afterward. You may borrow them if you wish!
Click to expand...

Hi Gerry,

it does have one normal bleeder. They must be 'orderable" from a brake place these days. I'll just get one of the kids to pump the pedal for me to bleed them when I'm ready. It'll work fine, I just let the brake fluid spray onto my floor (it can mix with the coolant, water, lhm, gearbox oil, diff oil, engine oil.... etc already nicely soaking into it :rolleyes: ). So lets so ... 2028 given how quickly i get back to stuff :) ..... The old car needs lots of work, but I might just do the brakes and drive it around town over this summer and see what is what .... I know the top ball joints are sloppy, most of the boots in the suspension are junk. My father said one of the lower ball joints was no good (I haven't noticed that one yet) and he sourced another set of lower arms as he couldn't get the ball joint out. Everything in time. lets just give it a run for around town over summer this year and see if its going to overheat and need the head removed and a distribution tube added.

seeya,
Shane L.
 
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citroenthusiast said:
I think you may find that the two-piece bleeder can be replaced by a single 7/16-20 SAE bleeder screw.
Click to expand...
7/16 .... 11.13mm. Hmm, that's interesting. Are the threads that close, they will screw in? because my thread pitch gauges and calipers think this is a metric fastener :)
 
DoubleChevron said:
7/16 .... 11.13mm. Hmm, that's interesting. Are the threads that close, they will screw in? because my thread pitch gauges and calipers think this is a metric fastener :)
Click to expand...
Remember, the wheel cylinders are Lockheed/Girling so they are going to have Imperial threads. 1.25mm pitch is 20.32 threads per inch, so it would be really easy to misinterpret 20TPI as 1.25mm pitch.
 
citroenthusiast said:
Remember, the wheel cylinders are Lockheed/Girling so they are going to have Imperial threads. 1.25mm pitch is 20.32 threads per inch, so it would be really easy to misinterpret 20TPI as 1.25mm pitch.
Click to expand...
Oh gee's. They are that close they would probably work together. The bolt in the back is also a Citroen A/F bolt then? What would be so close to M6 x 0.9 that a metric thread gauge would fit perfectly :) Oh, its 1/4" .... if that bolt was metric is would measure about 5.8mm ...not 5.96mm. 1/4" is 6.35mm

Now THAT would be confusing to find in your fasteners box.... An AF citroen fastener.
 
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I think the two-piece bleeder is a Citroen invention, so it may very well have SAE male threads and metric internal threads, similar to the adapters for the flexible brake lines, which have a mixture of SAE and metric threads. As I mentioned previously, I did replace the two-piece bleeders on my '54 with some SAE bleed nipples and they worked. Your measurements helped me reconstruct what the dimensions were.
 
1/4" UNF - 28 threads per inch. Simple calculation: 25.4 / 0.9

Similarly, check out 7/16" UNF - 20 threads per inch.

I'll see if I have a spare thread gauge in threads per inch sizes.

Roger
 
DoubleChevron said:
Hi Gerry,

it does have one normal bleeder. They must be 'orderable" from a brake place these days. I'll just get one of the kids to pump the pedal for me to bleed them when I'm ready. It'll work fine, I just let the brake fluid spray onto my floor (it can mix with the coolant, water, lhm, gearbox oil, diff oil, engine oil.... etc already nicely soaking into it :rolleyes: ). So lets so ... 2028 given how quickly i get back to stuff :) ..... The old car needs lots of work, but I might just do the brakes and drive it around town over this summer and see what is what .... I know the top ball joints are sloppy, most of the boots in the suspension are junk. My father said one of the lower ball joints was no good (I haven't noticed that one yet) and he sourced another set of lower arms as he couldn't get the ball joint out. Everything in time. lets just give it a run for around town over summer this year and see if its going to overheat and need the head removed and a distribution tube added.

seeya,
Shane L.
Click to expand...
Yes, that system works, but fluid all over freshly painted cradle, arms, drive shafts and back plates will really make a mess.
I noticed when I put all new wheel cylinders into the Light 15 that they had bleeders in them that had a nipple machined into them. However, the diameter of those bleeders was smaller than the original so that they cannot be interchanged. I too would like to fit newer bleeders with an integral nipple so can you let me know if you have any success chasing up John's suggestion?
 
citroenthusiast said:
Yes, that system works, but fluid all over freshly painted cradle, arms, drive shafts and back plates will really make a mess.
I noticed when I put all new wheel cylinders into the Light 15 that they had bleeders in them that had a nipple machined into them. However, the diameter of those bleeders was smaller than the original so that they cannot be interchanged. I too would like to fit newer bleeders with an integral nipple so can you let me know if you have any success chasing up John's suggestion?
Click to expand...

Hi Gerry,

have a look on ebay. 7/16 x 20 TPI (turns per inch) are very common :) I can get you a set locally no doubt :)

seeya
Shane L.
 
citroenthusiast said:
To those of us who speak Imperial on a regular basis, TPI is actually "threads per inch," but I will forgive the easy mistranslation of the initialism :)
Click to expand...

Ah yes ... you have to like the countries that are a century or two behind the rest of the world .... I made a nice curry last week. It suggested a lot of spices .... 3 / 4 teaspoons of chilli powder among everything else.... hmmm... lets err on the side of caution, so for 3 -> 4 teapsons I decided on 4 teaspoons. It was a nice toasty warm curry. It occured to me later .... the recipe probably said 3/4 ... 0.75 teaspoons of chilli powder. Not 3 -> 4 teaspoons.


Oh well, I'm sure not to do that again for at least another week :ROFLMAO:
 
Yes, and we still think in terms of miles per gallon, which is a ridiculous measurement if you think about it because you can't average miles per gallon as you can liters per 100 km when talking about more than one vehicle......
 
FWIW, since flare fittings on the pressure side of the 11's brake system are 1/4 inch 45 degree SAE fittings, the male flare fittings (e.g. the adapters between the frame and the flexible lines) are threaded 7/16-20. If you have one of these handy, you can thread it into the bleeder port of the wheel cylinder to confirm they are threaded 7/16-20
 
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