M939-A2 Cooling Fan Air Valve Question

[99nouns]

Hello all, as it seems new year comes with new challenges, which keeps things exciting.

So I have noticed that my radiator fan is engaged when I start my engine in the morning while cold, as I inspected the area I heard hissing sound from the pin hole on the air valve.



I did my searched in the forums and I have seen several people has successfully broke it a part and clean/change O rings and it was as good as new, so I decided to do the same but it seems like I got stuck in 2 places.

1- There are 2 elbows on the valve, one say IN and other is OUT, the elbow on the OUT side is seems like clogged or has been installed some type of particle filter, so if someone look at the pictures and chime in on that, I would appreciate it if what you see is normal. IN side elbow is clear, has nothing.



2- I have bought a pin wrench to be able to remove the back plate as it seems to be made of aluminum, but that thing is so solid closed there I cant budge it a bit, I slightly damaged both the pin holes and the pin wrench and now wrench just slips out of the holes, is there a trick that you can recommend doing to be able to remove the back plate?



Thank you all,

 

[Jbulach]

The filter elbow is normal for the INPUT side. I used the tail end of two snug fitting drill bits and a square shafted screw driver to get the cap off, my other one had marks on it where someone used a pipe wrench. Be sure to make note of how many threads are showing on the other end. I still haven’t got my temperature dialed in since resealing mine.

 

[99nouns]

I didn't know that sensing end thread length actually would adjust the engagement temperature, my intention is not to even touch that side, or do I have to take the sensing part off to be able to access inside?

Thank you for the drill bit trick, I still dont understand how did you attach the drill bits to end of a square shaft screwdriver,

 

[99nouns]

Ok, I was able to remove the back cover, I need a new O-ring that is impossible to find kind.

Anyone got spare?

 

[99nouns]

I found the O ring on ebay 10 for 4bucks


Metric Buna O-rings 12 x 3mm Price for 10 pcs

 

[Jbulach]

I didn't know that sensing end thread length actually would adjust the engagement temperature, my intention is not to even touch that side, or do I have to take the sensing part off to be able to access inside?

Thank you for the drill bit trick, I still dont understand how did you attach the drill bits to end of a square shaft screwdriver,

For the simple seals you don’t have to take the probe side apart, but when I rebuilt mine it caused a temperature shift. It may be junk now, but... I went to far with the adjustment and was chasing it around this summer, not messing with it anymore this winter, as I’m toward the hot side now. used a #13 and #14 drill bit, used a square screw driver to keep in a tight sheer on those brittle drill bits. This is the seal I ordered, straight from Ghina, through ebay or amazon. Seemed to worked perfectly... except the whole temperature shift thing.

 

[simp5782]

Or just ditch it and go with a long term solution. It also gives you the advantage of using the fan clutch as an engine brake.

Horton # 993935 is a 205/197 switch and solenoid

 

[99nouns]

Haha, Wes I need to win the lottery before I can buy that, its a 300 part.

But I like the idea, thank you.

 

[simp5782]

Haha, Wes I need to win the lottery before I can buy that, its a 300 part.

But I like the idea, thank you.

300 part. Mine has lasted nearly 150,000 miles.without issue though. The shutterstats I am just not fond of.

 

[99nouns]

You are right but $300 is something I dont have right now.

 

[simp5782]

I'll look around for some extra ones. I think I've got a few solenoids laying around.

 

[99nouns]

Wes you the man, thanks brother.