Removing fan on M130 engine

[gmask]

I'm trying to remove the fan on my 250 and I can seem to figure out how you are supposed to keep the pulley from turning while unscrewing the bolts. I thought that there might be a hex key somewhere on the pulley but I can't find it and it's not shown in the exploded parts diagram I have.

I have read that it is possible to rtemove the fan without removing the radiator. With or without the radiator in palce I don't see how you are to get the appropriate leverage to back out these bolts. To make matters worse I noticed that one bolt head was stripped .. probably due to the previous mechanic(not a MB specialist) not knowing how to do this either and using one of the bolts as the leverage.

If you know how to do this please give me the technique ;-)

Thanks

Adrian

[hill]

Put some pressure on the fan belt. Then try to loosen it.

[MikeTangas]

If it's like the fan on the 4.5 I use an extra 10mm box on one of the unloosened bolts to hold the assembly stationary. Once the other three have been loosened, I'll gently snug one back up and use it to hold steady while loosening the fourth. Once the fourth has been broke free, it is a simple matter of a quick yank to unsnug that bolt used to hold everything still.

Now you can remove all the bolts by hand and carefully remove the fan, leaving the belt(s) attached to the pully which remains on the water pump flange. Thread two bolts back through the pully, finger tight, to retain the pulley to the flange.

[gmask]

I will have to grind down the box end to get these bolts off as the fan flange is too close to the head of the bolts. The open end is stripping them.. way too easily. Since I allready have another project that requires a modified 15mm socket with "thin" walls I'm going to buy a bench grinder/sander so I can make some "good" tools.

Pressing on the belt BTW seems to work well enough to hold the pulley in place and one bolt actually came free doing this... Worse case scenerio willr equire cutting the heads off and then extractor the bolts stubs. So I might end up taking the radiator out anyway.

Did Mercedes make this difficult on purpose? Was there a special thin box wrench? Seems like they figured this problem out on later cars.

[cth350]

Use the sears 10mm 6 point combo wrench. Yeah, sometimes it won't fit. But you only need the box end for the initial loosening.

I own 6 of the things. Of course, that's because I only know where the last two I bought are.

-CTH

[gmask]

Originally posted by cth350
Use the sears 10mm 6 point combo wrench. Yeah, sometimes it won't fit. But you only need the box end for the initial loosening.

I own 6 of the things. Of course, that's because I only know where the last two I bought are.

-CTH

If all else fails I will seek out a Sears. I allready bought the grinder and several more wrenches to experiment with and or destroy.

I plan on getting a replacement set of bolts for the fan so I was thinking I might beable to drill into the side of the bolt head and turn them loose with a small hex driver rather than doin gsomehting even more invasive.

[cth350]

If a bolt is not coming free, use liquid wrench on it (or Kroil; Kroil is better). If that won't do it, use heat. A MAPP torch will do you well.

-CTH

[Aaron]

All the fans are held on with 10mm bolts. So grind down the box end of your wrench, preferably a long handle type. MAC makes nice ones. A 12 point box-end is fine, just make sure it gets a good bite on the bolt head.

[gmask]

The ground down box end worked pretty well. Between the two cars only one was so stripped that the box end wouldn't grab. I tried drilling into the side of it and broke several hex keys trying to turn it but I think the hammering on it loosened it and I was able to remove it with some pliers. Note: this one was stripped by the previous mechanic..

Putting it back together was almost as much fun as taking it apart.

Soon I will test drive it ith the parts fan and shroud to see if it runs any cooler.

I'll let you know the results.. thanks for all the tips!