Replacing a bent valve stem

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Model T Ford Forum: Forum 2018: Replacing a bent valve stem
Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Friday, January 12, 2018 - 11:29 pm:


November's unfortunate misadventure not only broke a wheel...


...it also left a valve stem bent.


Trying to straighten it was futile. All I succeeded in doing was breaking off the small end.


So I removed the nut and bridge washer and pulled out the bad stem.


Fortunately I had a spare original that I picked up at Chickasha last year.


It was interesting to find that the remains of the old red tube contained a few layers of fabric.


By good luck I also had an original bridge washer of the right size.


A snap ring spreader was just the right tool for inserting the stem into the tube.


Ready to be fastened in place.


Nut and bridge washer tightened down to seal.


Unfortunately I couldn't get the clincher to clinch all the way around. I thought some air might help it along. All that did was make the tube bulge out between the rim and the tire until it popped like a balloon. I couldn't remove the valve from the stem in time to stop it.


So I cut the rubber stem off a new tube and installed the metal stem.


This time I got the clincher properly seated so it clinches and holds in the tube. Mister Thrifty likes the rubber stem tubes costing $13 less than the metal stemmed ones. I think I paid $1 for that original stem.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Nevin Gough on Saturday, January 13, 2018 - 06:36 am:

Thanks for sharing Steve. Great pictures and very informative.


Top of pagePrevious messageNext messageBottom of page Link to this message  By James G Fisher III Peachtree City, GA on Saturday, January 13, 2018 - 07:27 am:

Very cool. Makes me want to pull off my tires and put that type in. Thanks Steve


Top of pagePrevious messageNext messageBottom of page Link to this message  By Herb Iffrig on Saturday, January 13, 2018 - 08:02 am:

I noticed in the photo of the tube you took the metal stem out of, that the tube appears to have an extra layer of rubber around the hole the metal stem was in. Would it be advisable to put a patch with a hole in it over the stem hole to reinforce it before inserting the metal stem?


Top of pagePrevious messageNext messageBottom of page Link to this message  By Terry & Sharon Miller, Westminster, CO on Saturday, January 13, 2018 - 08:42 am:

Herb,

Great question. I would like to see a photo thread of the process of taking a rubber stemmed tube and converting it to a metal stemmed tube.

I expect cutting out the rubber stem part to be the most critical procedure so as to not damage the tube making it unusable.

Mr. Jelf, are you up to the challenge? I'm sure it would help a bunch of us. I sure do appreciate you sharing your wisdom. You have helped me a great deal and I haven't even started the rebuilding phase of my restoration projects.

Thank You,
Terry


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Saturday, January 13, 2018 - 09:03 am:

http://www.mtfca.com/discus/messages/599638/640373.html


Top of pagePrevious messageNext messageBottom of page Link to this message  By David Dufault on Saturday, January 13, 2018 - 09:16 am:

Patience and persistence personified AND perfect photos - Thanks Mr. Thrifty! :-)


Top of pagePrevious messageNext messageBottom of page Link to this message  By Terry & Sharon Miller, Westminster, CO on Saturday, January 13, 2018 - 09:29 am:

Mark,

Thank you for the link. I didn't find that one.

Terry


Top of pagePrevious messageNext messageBottom of page Link to this message  By Mark Strange - Hillsboro, MO on Saturday, January 13, 2018 - 09:50 am:

The currently available metal stemmed tubes from the vendors have stems that are larger than true Model T size. The dust covers don't look quite right either.

Model Ts originally came with Schrader 777 stems when they were new.

Here is what an original Schrader 777 stem and its associated hardware look like.

Schrader 888 stems are similar, but the stems and dust covers are 1/4 inch shorter.

It can take a lot of digging through coffee cans and boxes at Hershey and other swap meets to get a full set of correct stems and hardware. :-)


pic1

pic2


Top of pagePrevious messageNext messageBottom of page Link to this message  By William Dizer on Saturday, January 13, 2018 - 10:29 am:

As a tire dealer/mechanic, I learned years ago to ALWAYS take the valve core out when first airing up/seating a bead, so that if a problem occurs, you can let pressure off quickly. When installing a tube in a tire air it up, then let all the air back out completely, install the core, and re air it. This helps let wrinkles in the tube relax and be eliminated. If a tube remains wrinkled, it will often fail where the fold is.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dick Fischer - Arroyo Grande, CA on Saturday, January 13, 2018 - 10:53 am:

Here is a link to another tutorial on replacing rubber a stem with a metal. Excellent step by step photos.

http://sheepisland.com/cars/tech/metal_stems/


Top of pagePrevious messageNext messageBottom of page Link to this message  By Terry & Sharon Miller, Westminster, CO on Saturday, January 13, 2018 - 11:12 am:

Dick,

Thank You. I agree, excellent tutorial. Very easy to understand each step and the details involved.

Terry


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Jelf, Parkerfield KS on Saturday, January 13, 2018 - 12:37 pm:

Not only do the stems come in different lengths, but there are at least two different widths. The 777 and 888 stems, and an unidentified longer one in my drawer, all measure .400". The modern one I replaced is .480" and also longer than a 777. I was lucky to have that old timer (Schrader 725) that matched it. I'd be interested to know what cars originally used these large stems now being sold for use on Model T's.

Note that the original bridge washer I used, and the ones shown in Mark's pictures, have a raised bead to press into the rubber. The stem base inside the tube has the same bead, so the two parts press into the rubber from both sides to make a good seal. The modern bridge washers currently being sold are flat.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dave Young in Mays Landing, NJ on Saturday, January 13, 2018 - 01:56 pm:

Steve,
You're pretty darned talented at posting pictures, too. Very informative step-by-step. Thank you.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Steve Tomaso - Longbranch,WA on Saturday, January 13, 2018 - 05:55 pm:

Hell, I thought you "over-revved" the old girl and bent a valve - the other kind !!!


Top of pagePrevious messageNext messageBottom of page Link to this message  By Dick Fischer - Arroyo Grande, CA on Saturday, January 13, 2018 - 07:02 pm:

Steve, The photo of your torn inner tube is most interesting. Do you have any idea how much a big company would have to pay some computer weenie to create a logo as artistic as those tears ?

Ignore the thorns, smell the roses.

Dick


Top of pagePrevious messageNext messageBottom of page Link to this message  By Allan Bennett - Australia on Sunday, January 14, 2018 - 12:42 am:

Steve, old time tubes with metal stems were reinforced around the valve hole with a layer of fabric vulcanised between layers of rubber. this resulted in a thicker tube where the valve stem was fitted. As well as reinforcing the hole, the fabric reduced the tendency for the rubber to be squished aside as the nut was wound down to seal the valve in the tube.

When fitting original stems in today's thinner tubes, I like to leave a low ridge of the rubber stem in place, rather than sand it dead flat. It gives the hole a little more strength. The only lubricant I use is a little spit. Rubber grease and/or silicone act as lubricants and will allow the rubber to squish out between the base of the valve and the bridge washer. The bridge washer absolutely needs the ridge around it, making the flat modern reproductions useless.

Hope this helps.
Allan from down under.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith, Lomita, California on Sunday, January 14, 2018 - 10:52 am:

I like Marks post the best. Yes, Ford did use the 777 valve stems, but I prefer the 888's because they are the shortest valve stem that works. Last week there were a number of these on ebay for sale. Mark is also correct in mentioning the vulcanized valve stems the vendors sell are incorrect. They don't do their research! My wish is that a Model T vendor would do like A&L Model A parts Company did for Model A's. With Schraders permission, they copied the correct Model A stems exactly. It must have been a huge expense for them, but the result is perfect.


Top of pagePrevious messageNext messageBottom of page Link to this message  By Larry Smith, Lomita, California on Sunday, January 14, 2018 - 10:55 am:

I like Marks post the best. Yes, Ford did use the 777 valve stems, but I prefer the 888's because they are the shortest valve stem that works. Last week there were a number of these on ebay for sale. Mark is also correct in mentioning the vulcanized valve stems the vendors sell are incorrect. They don't do their research! My wish is that a Model T vendor would do like A&L Model A parts Company did for Model A's. With Schraders permission, they copied the correct Model A stems exactly. It must have been a huge expense for them, but the result is perfect.


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