Shutterstat Removal and Replace Procedure

[neoneddy]

I've done some due diligence and searched for this with no luck.

I have a shutterstat on the way from C & J bus Repair of Bloomington, nice folks there, I'm considering swapping it out myself.

I've put a wrench on it as-is with no luck in getting it to budge, I haven't really laid into it until I have something to plug the hole with .

So any tips on this would be great, my biggest fear is introducing significant air into the coolant lines.

[gumpy]

You're going to replace this without draining the coolant?

[eagle19952]

You're going to replace this without draining the coolant?

which would not be a good idea...
in-fact, draining and fashioning multiple air bleeds at this time would be a huge plus.
the tstat crossovers used to all have one,
adding one to a rear area of each head...would eliminate your concern.

[chessie4905]

With no pressure on coolant system, you should be able to quickly change to new one with minimal coolant loss. Have the threads on new one properly coated with wrap or sealant. Loosen old one till you can turn it by hand. Unthread, remove, and quickly thread in new one.

[eagle19952]

With no pressure on coolant system, you should be able to quickly change to new one with minimal coolant loss. Have the threads on new one properly coated with wrap or sealant. Loosen old one till you can turn it by hand. Unthread, remove, and quickly thread in new one.

and bleed the air void off where...?

[neoneddy]

Initially that was my thought like chessie said. I'd think the air bubble would work it's way up to the reserve tank.


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[eagle19952]

Initially that was my thought like chessie said. I'd think the air bubble would work it's way up to the reserve tank.


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a risk that many have wished they had not taken.
but, busnut way. there are many.
good luck.

[chessie4905]

If coolant is coming out of hole, any air will have to go into overflow tank if it is open while you do this. We're talking about about a pint of coolant loss or less. If you are concerned about air pocket, drive it around at moderate speed after a good amount of idling time with heaters on high. I can see concern about an air pocket if we're talking about a couple of gallons of loss or removal. But can't hurt to be super cautious if you feel anxious.

[neoneddy]

I'd think if I have the new fitting ready to go and the old one loose with an unpressurized  system I could do it with  a cup or less of loss.  The hole would be unobstructed  for what maybe 1/2  second?  then any seepage would be around the threads.

I putzsed with it some yesterday,  never did get it to budge.   I might try some heat on the outer flange to get it to expand away from the cold shutterstat.

Here in Central MN it went from 57 (crzy warm) to the 20s in a matter of hours... I might also just wait until spring.

[chessie4905]

Heat with a propane torch does wonders with years old thread sealing compound. Just did this last week with snapped off fitting I had to remove stub with easy out. Wouldn't budge without fear of snapping ez out. Heated with torch and came out easily.

[gumpy]

So do your shutters work properly? 

I assume you're changing this because your shutters are not opening and your bus is running hot?  Have you tried opening them manually by turning off the air supply to them using the valve on the regulator?  Did it make a difference on the operating temperature? 

[luvrbus]

If you need shutter parts I have a set from MCI C that are going in junk pile

[neoneddy]

Thanks for jumping in Craig,

Yes, currently the shutters do not open if the regulator is on at all.   If the shutters are open the engine does not get much above 140-145 in these temps.

From a previous thread it seems I might also have a thermostat issue.  I suspect however that in the spring when I was finding air leaks I heard a hissing from the regulator and figured "What's this do? .. huh if I turn the knob down it stops.  Sweet one leak found" and now I'm realizing what it was for.

It seems even if I do have a thermostat issue I should also get the shutters working right because it cna help with warmup and in-traffic driving in the colder months.   I'm planning on taking the it out in the early spring for a trip and I'd like this working as good as it can.

[bevans6]

I changed my shutterstat without draining fluid, zero issues.  Get the old one loose enough to turn by hand, have the new one prepped and ready to go, old one out, thumb over hole, new one in and press hard and turn fast.  Any air bubble will instantly rise to the top of the radiator (that is where that pipe goes to) and be voided.  Didn't even need to top off fluid.

Brian

[gumpy]

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