Master Cylinder Vent Valve and Elbow

[w30bob]

Hi Guys,

I was rebuilding a used M37 master cylinder I picked up at a meet for cheap and broke off the brass vent valve that attaches to the lid. So I started looking around locally for the same valve, but as with most parts this old you know the drill.......it couldn't be found. The NAPA guy gave me that look again.

So I went to the ORD 9 and found the original manufacturer's name, which was Weatherhead, and started looking online. Much to my surprise Weatherhead is still in business (but now owned by Eaton) and making brass valves and fittings. The ORD part number was useless, but I was able to actually find the valve in question after an hour or so of catalog diving, as well as the little 90 degree elbow that attaches the valve to the flared vent line tube. Digging deeper into some diesel engine forums I found that NAPA actually carries this valve (part number WH 6820) but they want like $14 for one. More digging online and I found a company called MSC Industrial that has them for less than $5. So I ordered a handful along with a bunch of 90 degree elbows (ORD says I need 5 for my truck) and even the shipping wasn't bad. A few other industrial supply houses had these parts but just kill you on shipping.

So if anyone ever needs to replace that vent valve on the master cylinder or the 90 degree elbow, the Weatherhead part numbers are;

Needle Valve 1/8 Male Pipe to 1/8 Female Pipe): PN 6820
Elbow (3/16 Tube to 1/8 Male Pipe): PN 402X3

Probably more useless info for most, but just in case there's one frustrated M37 owner out there kicking the dog because he can't find a master cylinder vent valve..........this info is for you. Now leave that damn dog alone you sicko.

regards,
bob

[refit1701]

Great info....I can't find the thumbs up button!

[pwrwagonfire]

Great info! Thanks for sharing your detective work with us

-T

[jrodjared]

Fantastic! Are those the same brass fittings used elsewhere like on the oil filter housing and vent tubes?

[jrodjared]

I also ran across this:

http://shop.willysamerica.com/Elbow-90-p/gm137421.htm

It matches the part number in TM-1840A (ELBOW-137421). Should work for some of those 90 vent and oil fitting I messed up getting it all apart

[John_C]

Thanks for the information. MSC is now up to $14.95 and NAPA is $29.95. MSC wants $12 for shipping, so I think I'll buy locally at NAPA. I was happy to find your post because I've already spent a couple of hours searching for this. I shoud have come to the forum first.

John

[NAM VET]

well, isn't that quite the coincidence. When I get home tomorrow PM, my next project is to look into my MC fluid and vent valve/line to see what is needed there, as part of my restoration project. Helpful post, even if from several years ago. The NAPA guy now knows my first name.

all the best...
NV