Help me find 3/8 UNF blanking screw

[malcolm]

I'm adding a remote brake servo to my Renault. The circuit was always single circuit, but the master cylinder was previously used for distribution and has 4 outlets. I only need one as the 4 way distribution is now going happen after the servo.

It used to be possible to buy 5/16 UNF blanking bolts that seal with little copper washers for the unused outlets, but my local motor factor doesn't have them, and I can't seem to locate any on the internet.

They must be used in other applications! Anyone have any ideas about what they might be officially called or where to look for them?

 

[hotrodder]

Pipe plugs?

 

[malcolm]

Turns out they are 3/8 UNF. That might help my search a little I'll do the circuit again - plug sounds like a good word to use.

Edit - still a little stuck - a lit of these pipe plugs seem to have very short threads which make me a bit nervous.

 

[Uncle Joe]

Try someone that sells american car parts, and ask for Everco 500B if its to blank of 3/16" brake pipe.

 

[rikrobson]

You could use bleed nipples. They will be the correct thread.

they will also seal at the bottom of the thread so you will need to ensure there is a shoulder to seal against. There usually is so the pipe fittings can seal. also make sure that the nipples will be long enough to seal against the seat. Had a problem recently trying to fit a bleed nipple in a caliper that was too short and worrying why it was still leaking. (the old one was drilled out so i had no idea that the correct one was 3mm longer than a standard ford one!!)

This way the seal is hidden and not likely to get corroded. You could also seal up the bleed hole with solder to ensure no much gets in the hole.

 

[malcolm]

My first thought was to use bleed nipples, but my local motor factor didn't have them in the right size.

Would look a bit funny having a load of bleed nipples sticking out, but it would probably be the best solution for avoiding trapped air. And the surfaces are machined to take bleed nipples so it's correct too.

Thanks I've googled suppliers for that one and it's easy. I got distracted by the lack of availability from the motor factor.

Now just need to look for rubber sleeved P clips with M8 mountings that take 2 brake pipes and stand them off from eachother a little. Will solve that one using a larger size and a vice. It's a pain building something a little different.

 

[snowcat]

Malcolm might be worth squireling this away for future reference, these are my local guys who also do mail order, they would have you plugs no bother, fittings and pipe is all they do.....

 

[eil]

Are you sure they are 3/8 and not 7/16

 

[malcolm]

Went out to the garage to check as I got all into a confuzzle about the size. Male brake pipe connector screws very well into a 3/8 nut. Though the surface that isn't threaded (smaller than the diameter of the threaded bit) is 7/16. I know very little about threads so please correct me if I'm wrong.

 

[eil]

I know that you cant go on the pipe size,probably is 3/8 then, I shouldent confuzzle more should I

 

[rikrobson]

Where's the donor master cylinder from?

This will probably give you a clue. IRC then BMC cars were 3/8" the other option is that it's metric M10 with a 1mm pitch most cars after '73.

 

[zzr1200]

Malcolm, if you have a normal brake pipe union nut, you could always use a small ball bearing as a plug to seal the outlet.

 

[ballores]

Malcolm there used to be a company called brake and pipe or failing no internet joy ask at a scrappys they are very knowledgable

 

[Uncle Joe]

I sorry, but I have to disagree with you there. You can go off pipe sizes, although, as with everything else, there are exceptions.

As standard, 3/16" brake pipe uses a 3/8" UNF thread, 1/4" a 7/16", 5/16" a 1/2", 3/8" a 5/8" and 1/2" a 3/4"

There are some special nipples though that do deviate from this...but they arent standard.

 

[malcolm]

You can't necessarily tell from the year. The later Renault 4 had metric fittings at the front and imperial fittings at the rear! The one I'm building is completely imperial, but that's just by chance. The fittings I keep for brake pipe are 3/8 UNF and 10mm metric.

Pain to find the little bits though - online shops don't like to sell the small parts, only the big ones. I spy a gap in the market.

 

[Uncle Joe]

Malcolm, if you havent found what you are looking for yet, give Rodley motors a call, they've got everything you want in terms of brake fittings...though you have to understand the yorkshire dialect!

 

[simon718]

here's some 3/8 x 24tpi bleed nipples if they would be of any use?

 

[eil]

As you state uncle joe as standard you can go by pipe size, but there are exeptions and specials as you say, which means if you have them you cant go by pipe size.