FYI Heater valve shaft seal

bobhudsonMember

I may be the last owner to need a heater valve rebuild but in the event I'm not thought I would share this with you.

I decided to remove and inspect the 67 PG 18459A-A heater valve in my car since the hoses were not connected when I purchased it and did find the shaft seal had minor deterioration. I've read this is normally the cause for leaks. There was no reference to the shaft seal when searching the forum or web. I eventually found a 1/8" x 3/8" x 1/8" replacement V seal part # 870-41 for $1.18 at Hercules Sealing Products. This seems to fit properly and I'm sure will work. The plunger outer flange seal was fine and can't imagine finding one of those anywhere. The end cap seal is a standard 1" x 7/8" x 1/16" square o-ring.

This beats the heck out of paying $157 for a rebuilt valve plus core and shipping.

Hope this may help someone.

Bob

12/23/135:15 PM

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liv1sMember

It did help someone. Thanks for posting this way back in 2013 👍

4/2/2110:18 AM

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USCDOC13Member

Epic! Just ordered the gaskets. This thing was straight forward to take apart. Thanks so much @bobhudson !!!

1/15/226:10 PM

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bobhudsonMember

I was surprised to receive a reply on such an old post and so glad it helped. Thanks for the acknowledgement and for the forum archives!

1/16/225:11 AM

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bosswrenchMember

There are two different heater valves. Early one uses a bent rod while the later valve has a metal arm. Does your seal fit both?

1/18/225:24 PM

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bobhudsonMember

Mine was a '72 SN3242 pre L and seem to remember it was the early model valve with the bent rod so I have not seen disassembly of the later model. Hope someone else can help or maybe if you disassemble yours you can measure and order from the same company as I did back in 2013. Good luck!

1/18/228:05 PM

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USCDOC13Member

perfect fit. Mine is a ‘72

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1/24/2211:43 AM

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bosswrenchMember

Thanks, Bob. I used to rebuild valves with an o-ring from McMaster-Carr in L.A. Been so long I don't remember its p/n.

1/24/2212:27 PM

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bobhudsonMember

I should have posted pics back in 2013. I use the term "Been so long I don't remember" too often these days.

1/25/227:10 AM

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stevebuchananMember

I just now received some of the seals from Hercules Sealing Products and installed one into my heater valve that was leaking. The valve is now fixed. I also replaced the o-ring with #118 from Ace Hardware. I made a test rig and the heater valve is holding 25 PSI which is much more pressure than it will ever see in the car. Here is a photo of the test rig. I used a bicycle pump with a gauge to pressurize it to 25 PSI. The test rig is filled with water.

https://www.herculesus.com/pro...arch_text_new=870-41

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6/9/233:14 PM

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stevebuchananMember

I noticed that this seal is not as tall as the one from the factory. When the new was under pressure it seemed to work perfectly. Today I noticed that without pressure it slid back and forth in its cavity, traveling a fraction of an inch when the rod is moved back and forth. To fix it I put an o-ring behind the seal to act as a shim. Here is the size I used.