E30 Zone

How does one separate the fan from the water pump?

When stripping the engine for a bit of an overhaul I took the pump and fan off as one unit. Have now got a new pump to go on but can't figure to take the fan off the old pump.

TIA

It should just be a case of unscrewing the fan from the pump... Stopping the pump from spinning will be the hardest thing. Can you wrap the old belt around it and use that as a means of providing friction?

The fan should have a 32mm nut on the back of it, with the thread protruding through the pulley for the water pump. You should be able to see this thread on the new pump. Don't forget it's a left handed thread!

Good man, thanks Trigger

If the pump is off the engine, hold the rotor in a vice. 32mm spanner will need to be fairly thin to fit in the available gap.

Have vice Brian, this is my plan of action, though may have to take my grinder to my big adjustable, I don't think I have a 32mm spanner

No adjustable is going to fit in there, and a lot of conventional spanners won't, although the one I use is just an 'ordinary' double ended open spanner.
As above, spanners for the job are readily available, and it's also a size used on bicycles.

Perhaps I should stop being tight and buy one

Silverline spanners might be cheap and nasty - but they are thin! Not always what you want, but for viscous fan removal, just the ticket. Not a lot of cash to buy at all.

If you go on to e-bay and there is a "Fan Clutch Wrench Water Pump Holder Removal Tool" advertised. Simple piece of kit which if you can access some 10swg steel it would be easy to fashion for yourself.

Motorhole wrote:Silverline spanners might be cheap and nasty - but they are thin! Not always what you want, but for viscous fan removal, just the ticket. Not a lot of cash to buy at all.

Also doubles up to remove the oil filter housing cap on my E46 too.

Vise grip locking pliers have aways worked for me better than a ground down thin 32 mm spanner.....
Clout with lump hammer and its loose!

A hammer and chisel has never failed me.

Well, drama, all I've managed to do is undo the impeller off the shaft, and destroy the pump. Now stuck with the fan and shaft still bolted together, fair to say the bolt is seized Anyway, least of my problems, regards to thread title

What a tit, when I stripped everything down, I should probably have read the wiki first. I lined up the cam sprocket TDC, but didn't realise I should have lined up the crank TDC also, last belt I changed only had to mark the top.

So, whilst refitting the new belt i'm having trouble, what can I do to rectify the fact my crank TDC is about 6 inches from where it ought to be? Incidently, nothing has been moved from when I took the old belt off. Will it make any difference? Only what I'm finding is the difficulty in getting the belt in place with the roller in place, the belt to the right of the roller is all baggy and the on the side of the roller, too tight.

FFS what a knob

is it not a left hand thread on the fan clutch?

maxfield wrote:A hammer and chisel has never failed me.

I'm an advocate of capital punishment for anyone guilty of this!

Fan shouldn't even be tight by the standards of a bolt thread that size, but you can't be sure what whoever was there last has done. Loctite isn't unheard of.
You are trying to turn it clockwise, facing from the front of the fan, aren't you?
As long as you set the cam pulley to the timing mark first, and then the crank afterwards you won't do any damage, unless the crank was 120 degrees off either way.
When the cam belt is off, it's good practice to turn the crank 60 degrees off TDC, so that all the pistons are part way down the bores, and there is no possibility of valve contact, whatever you do with the camshaft and valves.

Brianmoooore wrote:

maxfield wrote:A hammer and chisel has never failed me.

I'm an advocate of capital punishment for anyone guilty of this!

I did used to have a laser viscous spanner, but I did come across a stubborn fan one day which cause the open spanner bit to splay open. So I've always used a hammer and a chisel ever since.

last time i did one i used (& still have) a 32mm spanner just for this job, it's 1/2inch thick & when used with a long extension bar does the jop perfectly.

hammer? yes, chisel?? not a chance.

Brianmoooore wrote:Fan shouldn't even be tight by the standards of a bolt thread that size, but you can't be sure what whoever was there last has done. Loctite isn't unheard of.
You are trying to turn it clockwise, facing from the front of the fan, aren't you?
As long as you set the cam pulley to the timing mark first, and then the crank afterwards you won't do any damage, unless the crank was 120 degrees off either way.
When the cam belt is off, it's good practice to turn the crank 60 degrees off TDC, so that all the pistons are part way down the bores, and there is no possibility of valve contact, whatever you do with the camshaft and valves.

Yes was trying to undo it the correct way, just won't shift. Not end of world, if it comes to it i'll just buy another fan.

Not too sure what you mean there Brian, I'll take a photo, that way it might make more sense to me.

If you have the crank pulley on the timing mark, then two of the pistons are right at the top of their bores. The same situation occurs with two other pistons if the crankshaft is 120 degrees (1/3 of a turn) either way from that point.
If the camshaft is turned independently of the crank, then valves are likely to make contact and damage will occur.
If the crank is turned 15 degrees from TDC, all the pistons will be well away from the top of the bores, and no damage will occur, whatever position you turn the camshaft to.
When the camshaft is turned so that the pulley is lined up with its timing mark, all the valves are firmly shut, except those of cylinder 1, and those will only be just off their seats, and safe from the piston.

Ok, from what you're suggesting, my crank is 1/3 of a turn away from the marks, it hasn't been moved independently of the cam shaft so, in theory, it should be safe to just put the new belt on?

Crank position.....



Cam position....

Jesus325iTouring wrote:Ok, from what you're suggesting, my crank is 1/3 of a turn away from the marks, it hasn't been moved independently of the cam shaft so, in theory, it should be safe to just put the new belt on?

?????? You're losing me here!
You are saying that the cam pulley is lined up to the mark, the crank pulley is well away from it, and neither have been moved since the belt was taken off?? There's something very strange about your engine if this is true.

Nothing has been moved, the cam and crank are in exactly the same place from when I took the belt off.

Have I flummuxed you Brian?