Fixing Your Ford E350 and Aerostar
Advice for Replacing Fuel Tank Straps & Repairing a Loud Fan Clutch
Sep 13, 2007
This weekly Q&A session answers your questions about cars and trucks. This week explores a Ford E350 with a loud fan clutch and a 1992 Ford Aerostar that needs new fuel tank straps.
Question: Ford E350 Fan Clutch
Vincent, I recently had the fan clutch replaced. (It was seized.) The new one cuts in okay but never cuts out even when the engine temperature goes down to cold. It only disengages when the vehicle is stopped for a few hours. When the old one was working properly it would only come on when the engine temp went toward the hot zone and would disengage once the temp came down. It doesn't howl like when it is seized but it's loud enough to be annoying.
Is the new one working properly? It has some drag when you turn the fan manually with the engine stopped.
Thank you,
Glenn Gibb
Answer:
Basically the answer to your question is the fan working properly is; is it overheating? If it's not overheating then it can be assumed it is working properly.
The fan drive clutch is a fluid coupling containing silicone oil. Fan speed is regulated by the torque-carrying capacity of the silicone oil. The more silicone oil is in the coupling, the greater the fan speed, and the less silicone oil, the slower the fan speed. The fan drive clutch used is the coiled bi-metallic thermostatic spring type. The fan drive clutch uses a heat-sensitive, coiled bi-metallic spring connected to an opening plate, to control fan speed based on cooling need.
Fan clutch noise can sometimes be noticed when the clutch is engaged for maximum cooling. Clutch noise is also noticeable within the first few minutes after starting the engine while the clutch is redistributing the silicone fluid to its normal, disengaged operating condition after settling for long periods of time (over night). However, continuous fan noise or an excessive roar indicates the clutch assembly is locked-up due to internal failure. Attempting to manually rotate the fan can check this condition. If the fan cannot be rotated manually or there is a rough, abrasive feel as it is rotated, the clutch should be replaced.
To check fan clutch operation:
- Run engine at a fast idle speed 1500 RPM until normal operating temperature is reached. Blocking off the front of the radiator with cardboard can do this more quickly. NOTE: Regardless of temperatures, the unit must be operated for at least 5 minutes immediately before being tested.
- Stop the engine and, using a glove or a cloth to protect your hands, immediately check the effort required to turn the fan.
- If consi
- ble effort is required, it can be assumed that the coupling is operating satisfactorily.
- If very
- le effort is required to turn the fan, the coupling is not operating properly and should be replaced.
- The clutch fan may be tested while the vehicle is being driven. To check, disconnect the bi-metallic spring, and rotate it 90° counterclockwise. This disables the temperature-controlled; freewheeling feature and the clutch performs like a conventional fan. If this cures the overheating condition, replace the clutch fan.
Question: 1992 Ford Aerostar
Dear Mr. Ciulla,
Both fuel tank straps, 1¾" wide are very rusted at 245,000 miles but van runs otherwise okay. The front strap on one part is eaten away so that only about 7/16" of the strap width remain in that spot. The question is, and I am special ordering from RADEX of Keene, NH straps no longer available elsewhere, how do you find a diagram of the entire gas tank/strap setup, and how do you safely remove the old straps and install the new ones?
Thank you in advance,
Ron Ruloff
Answer:
The replacement of the fuel tank straps is pretty straightforward. You may run into problems with rusted bolts but replacements are available from Ford should you need them. There were two tanks used, plastic and steel. If you have a plastic tank you'll have no worries with it. If you have a steel tank then you will almost certainly find a leak, or leaks, where the straps were. If that's the case, and you might be better off in any case, send the tank to a radiator shop and have it repaired.
When you install the new straps get a couple of pieces of sheet rubber, toolbox drawer liners work well, and cut it into strips a little wider than the strap and install it between the straps and the tank. This will help protect the fuel tank.
That's all for this week. Feel free to browse the archives for past topics. And, as always, if you are stuck and need an immediate answer you can always call Vince on the phone.
