Block off leaking shutterstat

[98G]

We've got a truck(M923A1) that's having trouble maintaining air pressure. It had a couple of constant leaks that we fixed, and several intermittent leaks (heisenbugs).

One of the leaks is the shutterstat. Fan is on. Whistling leak at the external vent port.

While obviously the long term solution is to replace the shutterstat, is there any reason I can't just put the bolts in the fan so it's constant on, and block off the air supply to the shutterstat? This would be a stop gap measure so the truck can be used while waiting for parts.

Operating conditions are low speed, loaded heavy (11 tons in a silage box) and ambient temps in the high 90's.

Anybody got a good source for a new shutterstat?

 

[charlesmann]

Why not just hook the airlines together, bypassing the shutterstat, yet keeping the fan going? You’ll need an AN4 jic male to male nipple

 

[simp5782]

Thermal switch unit and solenoid. You run a 24 wire from the fuel solenoid to the thermal unit

S-9084, Fan Clutch Solenoid Valve - Horton, Bendix, Kysor & Borg Warner Applications

NewStar Fan Clutch Solenoid Valve S9084 -Navistar International 4000 Series Medium Duty, Bendix 5008274, K058650, K058651, Navistar 1689785C91, Borg Warner 10560814501, GT DEV 5025-1, 5025-3, 5025-6

www.pscpartsstore.com

You need a switch from one of the chart below 195

Home

catalog.hortonww.com

 

[98G]

Why not just hook the airlines together, bypassing the shutterstat, yet keeping the fan going? You’ll need an AN4 jic male to male nipple

For anyone reading this looking for a resolution- AN4 male to male was the wrong size. The inlet was AN6 and the outlet was AN5. This was on a shutterstat dated March of 1984.

A custom little 2" hose from NAPA with a male AN6 and a male AN5 bypassed the shutterstat no problem.

At which point the downstream leak that had only been leaking before when the truck was hot, began to leak all the time.

The RIGHT way to fix this is to replace the shutterstat and resolve the downstream leak.

The RIGHT NOW way to fix this is to stick a bolt in the fan to lock it on, and block off air proximal to the shutterstat.

 

[charlesmann]

After seeing there are evidently different sizes out there, i went and double checked the shutterstat plumbing on both my 936A2s, and both trucks have an an4 in and an4 out. See attached pics.

If year model of shutterstat make a difference in fitting size, mine is 07 of 05.


It is NOT my intension to provide misinformation. I only went off memory of the fitting size on my truck.

 

[simp5782]

NHC250s use a 4 on the stat and and a 5 on the hose. 5s are odd

8.3s have all used 4s

 

[98G]

NHC250s use a 4 on the stat and and a 5 on the hose. 5s are odd

8.3s have all used 4s

Having done it today, it's emphatically an AN6 on the inlet and an AN5 on the outlet. NH250 and dated 1984.

I'm sure all of us are trying to avoid giving misinformation. Apparently there's at least two variations and probably more. The lesson to be taken is check yours before ordering/buying fittings.