Major air leak at Fan shutter-stat

[todds112]

So I just ordered some 3mm x 12mm and 3mm x 13mm O-rings from Mcmaster-Carr. Of course you have to order 10 each minimum. What the heck, I'll just throw another $20 at it. By the time I figure it out (if I do) I could have just bought a new actuator for $245.

 

[M35A2-AZ]

Well I had a air leak that started on my M929.
Has anyone came up with some good o-ring sizes that works for the valve?
I have read lots of post and it looks like a lot of people have not had good luck replacing the o-rings.

 

[todds112]

Well I had a air leak that started on my M929.
Has anyone came up with some good o-ring sizes that works for the valve?
I have read lots of post and it looks like a lot of people have not had good luck replacing the o-rings.

Still waiting. Haven't gotten the Metric O-Rings yet to try. Evans and Comfort Air are still researching it. I did just bite the bullet and buy a replacement actuator through Oshcosh Equipment...ouch. Figure I'll still try to fix the old one for a spare.

 

[todds112]

UPS just delivered the O-Rings. The 3x12mm one looks very promising and fits very well. I'll try it tomorrow. Too cold and dark to mess with it tonight!

 

[todds112]

Guarded success!! It doesn't leak now. Truck never got warm enough to engage it, so I don't know if that parts works yet.

Again it's 12x3mm O ring from McMAster-Carr 9263K126

 

[Alexsha]

Guarded success!! It doesn't leak now. Truck never got warm enough to engage it, so I don't know if that parts works yet.

Again it's 12x3mm O ring from McMAster-Carr 926kK126

Not a valid part #. It should start with 9262K. 9262K266 (Buna-N) is for a 3mm O-ring with 12mm ID. Is that the one? Or maybe 9263K126 (Viton® Fluoroelastomer)?

 

[todds112]

Not a valid part #. It should start with 9262K. 9262K266 (Buna-N) is for a 3mm O-ring with 12mm ID. Is that the one? Or maybe 9263K126 (Viton® Fluoroelastomer)?

Thanks for catching that. Fixed it. It is the Viton one.

 

[tbar123]

View attachment 538152

Does anyone know how to replace the inner o ring on the large end of the piece on the right? Thanks Todds for the picture.

 

[Scar59]

Tbar, If your asking what type of tool to use, you'll need a O ring pick or modified dental pick. That O ring gets brittle with age and you better have a spare because it may crack/break.

 

[Alexsha]

Hey Todds112, did you happen to measure the smaller orings? I'm going to order the 3mmx12mm one but I want to replace all 3.

 

[tbar123]

Tbar, If your asking what type of tool to use, you'll need a O ring pick or modified dental pick. That O ring gets brittle with age and you better have a spare because it may crack/break.

Scar, Not exactly. Inside of the larger end is a tiny o-ring. I was asking if there is a way to remove the cap and replace it. After looking at it closer (magnifier) It appears to be crimped on. SO no removal.But appreciate it anyway.

 

[todds112]

Hey Todds112, did you happen to measure the smaller orings? I'm going to order the 3mmx12mm one but I want to replace all 3.

No I didn't, but they were a standard size, sorry can't remember exactly what they were.

 

[Strouty]

Well, I have tried 4 times to get the thing working. Did you guys that ordered the seals from Mcmaster have good luck? I am going to start looking for a new one. It is frustrating, especially when you have a trailer hooked up, you have to leave it running or the air is gone.

 

[goober]

I just found a great source for the Shutter Stat for the M923, and other models that use the NHC250. Only $82. They said that they try to keep a few of these on the shelf. They were out when I called but said that they were going to make some new ones. Took a few weeks and finally received it. Looks great. I had rebuilt my old one with new o-rings but am keeping this new one as a spare.

www.rossairworks.com out of Elizabeth, NJ.

Part number is 1047-35000-29. It is a 185 degree shutter stat.

Note that I have not tried this in my M923 yet. I got this part number from someone on another forum.

 

[juanprado]

I just found a great source for the Shutter Stat for the M923, and other models that use the NHC250. Only $82. They said that they try to keep a few of these on the shelf. They were out when I called but said that they were going to make some new ones. Took a few weeks and finally received it. Looks great. I had rebuilt my old one with new o-rings but am keeping this new one as a spare.

www.rossairworks.com out of Elizabeth, NJ.

http://store.rossairworks.com/default.aspx?page=Item Search Results

Thanks for the info! Could you share the part number as the the shopping cart results are coming back to a generic page?

 

[goober]

Sorry. Part number is 1047-35000-29. It is a 185 degree shutter stat.

 

[User1]

Thanks for the good info. I ordered from Amazon Prime, got 25 O-Rings delivered for ~$14. Hopefully works.

Tip about jam nut O-ring is good one, been loosing coolant and it was mentioned a bad o-ring here will overpressurize coolant system. I never would have looked there for the problem.


M3x12 Viton O-Ring, 75A Durometer, Round, Black, Viton, 12 mm ID, 18 mm OD, 3 mm Width (Pack of 25)
Sold by: Amazon.com LLC

$13.73

 

[sweetk30]

I just found a great source for the Shutter Stat for the M923, and other models that use the NHC250. Only $82. They said that they try to keep a few of these on the shelf. They were out when I called but said that they were going to make some new ones. Took a few weeks and finally received it. Looks great. I had rebuilt my old one with new o-rings but am keeping this new one as a spare.

www.rossairworks.com out of Elizabeth, NJ.

Part number is 1047-35000-29. It is a 185 degree shutter stat.

Note that I have not tried this in my M923 yet. I got this part number from someone on another forum.

View attachment 566995

bump this old thread . . . anyone use this unit yet ?

the truck at work overheated the other day when using the crane unit . the fan was not on on the running engine.

I have a male/male 6jic fitting on order to test it .

but if it needs a new switch this looks the best .

 

[Swamp Donkey]

bump this old thread . . . anyone use this unit yet ?

the truck at work overheated the other day when using the crane unit . the fan was not on on the running engine.

I have a male/male 6jic fitting on order to test it .

but if it needs a new switch this looks the best .

It's a good unit. I've been running one on my truck for about a year now as a test. A few extra fittings will be required to install it.

I'm still partial to the Evans unit though, although I have several spares of both.

 

[74M35A2]

We need a "Thread from the dead" emoji, maybe a tombstone that says "Thread" on it. In this case, this one makes sense though.

If you run a 180 stat, and 185 fan switch, isn't your fan going to be on nearly all the time? That is not enough hysteresis.