Major air leak at Fan shutter-stat

[todds112]

So I started the truck up today to go over some things. Reset the CTIS and I'm still getting the 4 light error (leaking tire somewhere?). The truck aired up, but I noticed the secondary was having a rough time and coming up slowly. Then I noticed a strong hiss and traced it to the Shutter-stat. There is a small vent hole on the back of it and a strong stream of air was coming out, steadily draining the secondary air system.


Would this be a problem with the shutter-stat itself, or maybe a bad valve up-stream that's dumping air into it? I'm assuming if I remove the stat, a lot of coolant will come out. Trying to avoid making that mess right now, it's coooold.

 

[todds112]

OK I found a good thread with the same issue I am having. http://www.steelsoldiers.com/showthread.php?83932-Actuator-Air-Fan-Clutch-for-M923a1/page5

So now a related question: Could I pull the end off and take the guts out without loosing any coolant? Is the sensor end sealed off from the air end? Seems like it would have to be.

 

[todds112]

OMG! I just looked up what a new one costs. You've got to be kidding me!! Are they gold plated?!

 

[Alexsha]

You'll need to drain some coolant to get it off. I'd just drain into a cean bucket from the radiator. Remove, clean, and lube the shutter stat, replace, then pour the coolant back in.

I need to clean mine again. It's starting to stick open again.

 

[R Racing]

And while your in there you should replace the O rings.

 

[Floridianson]

Yes you can service in place without removing or loosing any fluid.

 

[Swamp Donkey]

Yes you can service in place without removing or loosing any fluid.

There is an O-ring behind the jam nut on the thermal capsule end. If that fails it will pressurize your cooling system and cause problems. There is also a spring loaded sliding tube on that end that needs to move freely. Best to remove it completely and service both ends.

As said above, just remove some coolant into a clean container from the radiator drain, remove the shutterstat and add the coolant back after installation.

Note: Don't mess with the tip/cap of the capsule. It's fragile and not serviceable.

 

[todds112]

Thanks all, I'll do it right and pull it, replace all O-rings. Hopefully that takes care of it.

 

[todds112]

Had a few extra minutes and decided to pull the guts out leaving the front part in the truck. I found the obvious problem.

The big O-ring was very hard and flattened on the outside surface. It wasn't broken, I did that removing it. The 2 smaller ones look fine, but I'll replace them too just to be safe. I noticed wrench marks on the valve body, so someone already was in the thing before. Can't get the parts till Friday of course.

Can not believe what a replacement costs. There's nothing to it, unless the sensor end is some space-age technology.

I'll pull the rest of it out of the radiator pipe and service it later if this gets me by. I hate messing with coolant a stuff like that in the winter.

 

[Floridianson]

Your welcome.

 

[todds112]

Looking at the pics from the other thread I see my valve is slightly different. My needle valve in the end cap is just plastic (the white pointy cone). In the others it is brass. I would be seriously ticked-off if I had to pay $250 for a new valve because that little $.05 piece failed.

Since there is no sign of any coolant in the valve body, I'm going to assume the other O-ring on the sensor end is good.

 

[Swamp Donkey]

The parts in my picture are from my spare. It has the plastic plunger. The one in my truck has the brass plunger. The brass plunger has an O-ring that seals the hole, which is replaceable. I agree that the brass is a better design than the plastic.

 

[todds112]

Anyone have any luck replacing the large O-Ring? I don't think it's a standard size. I'm having trouble matching it up.

I've emailed the manufacturer, Evans Tempcon, to see if I can get that seal/o-ring.

 

[shootist]

Todds
i looked for one for several days...it's not standard or metric.....
It is between a 205 & 206 metric in all 3 dimensions (id,od,width)
I finally located one at a hydraulic packing and insulation company.
a little snug but lubed it and ran truck on and off under load and it works fine
cost me .80 cents. I took old one in to place and it took a bit but we matched it up

 

[todds112]

Thanks, that's what I'm finding it's in-between everything. Hopefully I'll hear something back from Evans. I'll try a hydraulic shop next week.

 

[shootist]

Worst case I can go pick up another and mail it to you.
letme know how you make out

 

[todds112]

So, I finally heard back from Evans. They forwarded my email to a parts distributor, I CAN get the seal o-ring from them. They are $20.95 each (plus shipping), which is much better than $245 for a whole new actuator! I wasn't able to call today, but will call tomorrow and order one. I will post up the contact info, once I get it ordered and have it in my hand to verify.

Part was ordered 01/06/2015. Apparently it's a kit that contains all the O-rings.

 

[todds112]

Fail!

Arrrgh, finally got the parts from Evan's. They weren't sure what O-ring to send so they send me one of each they showed for the actuator. So I ended up with 4 different O-Rings ($5 ea) and none of them are the one I need!

Back to the drawing board. And I still have a dead-lined truck. I'm going to try to call them and actually talk to someone this time and explain what I need. Very frustrated at this point.

 

[Swamp Donkey]

Try these 2 part numbers at your local Cat house. I haven't had time to fully reassemble and test my spare with these installed but test fitting felt real good. The larger one is $5 and the smaller one is less than a buck. You'll need 2 of the smaller one.

Using multiple O-rings to determine nominal size for the larger one, I've come up with standard dimensions that should work. Try an O-ring with these dimensions: 1/2" ID x 3/4" OD x 1/8" CS. The cross sectional dimension seems to be the part that makes this a not so common size.





I have both of these O-rings installed but it'll be this weekend before I can completely assemble and test for proper function.

 

[todds112]

Using a micrometer on the worn one, I come up with 2.56mm thick and 12.99mm inside diameter. I found a listing for a metric one 3mm x 13mm. I'm trying to get my hands on one to test it.

The original is also not a true O-ring. It's kind of squared off. I think it's also a harder, almost plastic, material than most O-rings I can find.

The smaller ones are a standard size. Can't remember size off the top of my head, but found them in a standard kit.