M35 refill hydraulic fan clutch

[MrStabby]

If your M35 is overheating, check that the fan clutch is still supplying enough drive to move a decent amount of air. Fortunately, the fan clutch on the M35 is bolted together, which means it can be refilled. It will spin quite fast even it if it is completely stuffed. Search youtube for videos on how to check it (eg

1. Drive the car until everything is fully up to temperature. This will take a lot longer than to bring the temperature gauge up to its normal position.

2. Use an old magazine (or whatever) to slowly press against the spinning fan blades to slow them down. The fan will have a fair bit of momentum, even if the clutch is stuffed. I could hold the fan still with barely any pressure using my pinkie finger after it had slowed down. Again - watch some videos first.

If you confirm that the clutch is stuffed, you will need fluid to re-fill it. Many use Toyota fluid, example part numbers are 08816-03001 or 08816-06001 or 08816-10001, which are 3000, 6000 and 10000 CST respectively. Higher CST is thicker/more viscous. The Toyota fluid is about $17 for 12ml on ebay. The fluid is reported to be silicon oil, which cost me $20 for 50ml from a hobby store. You need about 80ml. I originally used 10000 cst from both Toyota and hobby store and they appeared the same. I don't know what viscosity is correct, but the car sounds like an old skool v8 with fan noise now, so its either correct or too viscous (or i added too much fluid).

EDIT: 10000 is definitely too thick - I have swapped it for 6000 which is better, but i'm still getting some belt squeal at high RPM, so either i have a belt/tension issue or its still too thick. Suggest 3000 as a starting point for anyone trying this.

Steps are;

1. Remove the air box snorkel, and air box.

2. Undo the 4 x 10mm headed nuts from the fan mount, and the 2 bolts holding the top of the fan shroud on, and lift them out together. This will require a bit of wriggling

3. Spray the bolts, screws and pin in the middle of the bi-metallic strip of the fan assembly with WD40, and leave to soak.

4. Take the fan off the fan clutch (10mm headed bolts)

5. Undo the phillips head screws holding the two halves of the clutch together, and pry them apart.

6. Leave the two halves upside down to drain the old fluid overnight, or clean them out with solvent. When i drained out the new 10000cst it didn't come out clean, so i'd recommend cleaning it out now, even though i didnt. AFAIK, WD40, Kerosine, Degreaser etc leave a greasy residue and will contaminate the new fluid, so brake cleaner is probably a better option.

7. Use needle nose pliers to verify that the pin at the center of the bi-metallic strip on the outside of clutch can turn a little / is not seized.

8. Fill the reservoir up with new fluid. I filled to the top of the first step, so about the level of the black rectangle in the centre.

9. Bolt the two halves together and re-attach the fan

10. Re-install the fan and shroud, being careful to get the tabs at the bottom of the shroud keyed in before you bolt the top on.

11. Beers

[West]

4 hours ago, MrStabby said:

If your M35 is overheating, check that the fan clutch is still supplying enough drive to move a decent amount of air. Fortunately, the fan clutch on the M35 is bolted together, which means it can be refilled. It will spin quite fast even it if it is completely stuffed. Search youtube for videos on how to check it (eg

1. Drive the car until everything is fully up to temperature. This will take a lot longer than to bring the temperature gauge up to its normal position.)

2. Use an old magazine (or whatever) to slowly press against the spinning fan blades to slow them down. The fan will have a fair bit of momentum, even if the clutch is stuffed. I could hold the fan still with barely any pressure using my pinkie finger after it had slowed down. Again - watch some videos first.

If you confirm that the clutch is stuffed, you will need fluid to re-fill it. Many use Toyota fluid, example part numbers are 08816-03001 or 08816-06001 or 08816-10001, which are 3000, 6000 and 10000 CST respectively. Higher CST is thicker/more viscous. The Toyota fluid is about $17 for 12ml on ebay. The fluid is reported to be silicon oil, which cost me $20 for 50ml from a hobby store. You need about 85ml. I used 10000 cst from both Toyota and hobby store and they appeared the same. I don't know what viscosity is correct, but the car sounds like an old skool v8 with fan noise now, so its either correct or too viscous (or i added too much fluid).

Steps are;

1. Remove the air box snorkel, and air box.

2. Undo the 4 x 10mm nuts from the fan, and the 2 bolts holding the top of the fan shroud on, and lift them out together. This will require a bit of wriggling

3. Spray the bolts, screws and pin in the middle of the bi-metallic strip, and leave to soak.

4. Take the fan off the fan clutch (10mm bolts)

5. Undo the phillips head screws holding the two halves of the clutch together, and pry them apart.

6. Leave the two halves upside down to drain the old fluid overnight, or clean them out with solvent.

7. Use needle nose pliers to verify that the pin at the center of the bi-metallic strip on the outside of clutch can turn a little / is not seized.

8. Fill the reservoir up with new fluid. I filled to the top of the second step, so about the level of the top of the screw heads. This may be more than is required.

9. Bolt the two halves together and re-attach the fan

10. Re-install the fan and shroud, being careful to get the tabs at the bottom of the shroud keyed in before you bolt the top on.

11. Beers

Wow great effort, thank you.