Rad Fan Replcement

[ChimpOnGas]

Hi guys,

I need to replace one rad fan, is this a rad out job or can it be done with the rad in left in place?

[s p a c e m a n]

Rad out, you probably could do it with the rad in place but it would take you 5 times as long. Try undoing the 4 bolts that hold the fan to the cowling before you start, but it will be a miracle if they all come out and then you have to fit them again. So then you've got to take the cowling off of the radiator, remove the bottom bolts by feel with little access and then put them back on again. Radiators held on by 2 bolts, 2 pipes and it generally wiggles straight out and then you can do the rest without bending over and fiddling in dirty holes

Just had a thought about whether you could undo the top bolts on the cowling and then bend it back enough to get your hand behind to help undo the fan bolts, but it sounds like a recipe for a cracked fiberglass disaster now that I've typed it out

Edited by s p a c e m a n on Wednesday 23 November 22:31

[Ptr400J]

When i took my rad out for a repair i took it out with fans attached , reason being i couldn't get to the bottom fan cowling bolts.

There are four down there, two each cowl, and they came out under protest....one breaking off in the process

It may be possible to undo the top bolts and bend the cowls back .
I think unless the rad has been out previously and the bottom bolts been out it may be difficult in situ

I hope someone has a better solution for you.

[s p a c e m a n]

^great minds and all that

I've fitted a set of wing bolts on the bottom of my cowling now so I can undo them easily with the rad installed.

[portzi]

s p a c e m a n said:

^great minds and all that

I've fitted a set of wing bolts on the bottom of my cowling now so I can undo them easily with the rad installed.

yes prevention is better than cure, if it looks rusty and manky clean, and replace if necessary. I got a nice brushed stainless Fan cowl with stainless bolts so no more rusting, wing nuts is a good idea.

[ClassiChimi]

Make a bonnet prop that allows the bonnet to go virtical.
Raise the front up to aid keeping water in the Heater matrix.
But you knew that already,
Replace mini exhaust bobbins while your at it and maybe any rusty hose clips

[ChimpOnGas]

Many thanks chaps, very helpful indeed.

If I'm honest with myself I kind of knew the answer was heading towards removing the rad, but thought I'd check if there were any cheats first.

Actually I probably should have started all this by explaining exactly what my problem is, so here goes.... My N/S rad is pulling excessive load which is welding the contacts of the relay shut from time to time, this does at least mean it fails safe with the fan running permanently until I pull the frozen relay.

I suspect the fan motor bearing is on the way out and the fan is partially seized, surprisingly there are no nasty noises but I can see a big drop in volts on my Canems software when the fan chimes in, and even with the voltage correction I've programmed into the fuelling the AFRs become slightly less stable at idle when the fan is on.

As the rad and cowls are relatively new and the problem started when they were fitted I guess it could just be a clearance issue between the fan & the cowl, but it seems odd there are no nasty noises? I had Surface & Design fit the new rad 18 months ago or so when I commissioned the Mk3 headlights, I guess its possible they either overtightened the cowl or the new cowl that came with the rad just doesn't offer enough clearance with the fan itself?

I'm on my third relay in 18 months so it needs sorting properly now, I'll investigate the cowl clearance theory at the weekend but ultimately I fear the rad will need to come out. For those of you who've removed your cowl and inspected the set up closely, does my fan to cowl clearance theory seem like a possibility to you or not? it would certainly save me the cost of a new fan if it is the source of my problem.

Fortunately because the rad is only 18 months old the bolts shouldn't be corroded, but as I didn't fit it myself any further top tips and tricks on rad removal would be much appreciated.

Thanks all,

Dave.

[s p a c e m a n]

I'd take the bonnet off, would make it a lot easier. Take the bolt off of the rod on one side and then the two bolts that hold the hinge to the car on the other and just slide it off. Put a bit of masking tape on the edge of the hinge before you take it off so that it's easy to line up when you put the bonnet back on.

[ChimpOnGas]

As this is only a N/S fan issue ideally I would rather leave the rad in place, doing so will save a lot of the inevitable mess and coolant bleeding, not to mention a few quid on antifreeze which TBH was changed only recently.

So I wonder if I could just ...

1. Remove the two top N/S cowl bolts

2. Measure up carefully and use a hole saw to cut two small access holes in the fibreglass lower front valance

3. Remove the two bottom N/S cowl bolts using a ratchet & extension gaining access through my new holes

4. Simply lift the whole N/S fan and cowl assembly out in one go without even touching the rad

To explain the idea better here is approximately where the fan cowl bolt access holes would need to be drilled in the fibreglass lower valance from under the car...



And now shown from the other side...



Question, "are the two lower cowl mounting bolt positions a mirror of the two at the top? (See arrows)



In theory if the bolt positions are mirrored top & bottom, with a bit of careful measuring I can accurately cut my new lower valance holes directly over the bolt heads for easy and direct access with my ratchet and extension. Drilling the lower cowl bolt access holes through the front valance sounds a bit drastic but lets be honest no one is ever going to see two small holes there, and I can use closing grommets to neatly fill them anyway.

Looking at the next photo of the bottom of the rad cowl mounting the lower cowl bolts do indeed (to me) look like their position is mirrored with the top bolts, if someone can confirm this it will really help me make sure I drill my holes in exactly the correct spot.



Much like the wing nut idea others have suggested, my two new lower cowl bolt access holes will also make future fan removal easy and eliminate the need to remove the rad, they would also make good drain holes as I've noticed the valance can sometimes collect water in inclement weather.

I appreciate it's a bit of a cheat, but do you guys think my simple bolt access hole idea will work?



Edit: I've just noticed the fans are joined in the middle, so I'd need to remove both fans together rather than just my suspect N/S one, but the idea is exactly the same, I'd just need to drill four access holes (two either side) and the whole joined in the middle double fan & cowl assembly can be lifted out from the engine bay in one go.





NB: Probably the most words ever used to describe drilling four holes, I almost certainly could have gone out to the the garage and actually drilled them in the valance faster

Edited by ChimpOnGas on Thursday 24th November 11:40

[ClassiChimi]

this might be a quick release idea and a good one too but I'm still inclined to think it's better to remove the rad.
If you've had the lower bolts out fairly recently then ok it should work.
I see this as an opportunity to check my horns, water bottle etc, even paint the section in front of the rad black which looks great when viewed from the front or just to be able to wah/clean/polish up the chassis and Y piece etc.

Hmm not really a good time of year to be outside doing it on the drive mind!,
Good idea Dave without looking I'd just check your not drilling into the fibreglass that's thicker near the appature,
The channel that the rad sort of sits in on mine has weep holes pre drilled into it so there's some reference.

[s p a c e m a n]

You can easily remove the bottom cowling bolts with a spanner with the rad in place as long as they're not corroded, couple of turns to get them loose and then undothe rest with your fingers. I've done it a couple of times because my rad is slightly bigger than standard so it helped give me some more wiggle room. Putting them back in will be a faff though, it'll probably take as long as removing the radiator to do it but yeah, you'll save on coolant. You could also undo the two mounting bolts for the radiator and lift it up a bit and pull the bottom around with all of the hoses still attached if you need a bit more room.

I'd just prefer to remove the rad to tidy other bits up and check bits whilst it's off, but if you've just had yours all done then try to do it with the rad in place first

Mine aren't joined in the middle, you should be able to remove the nearside one on its own, the other is a pig because of the pipe on the bottom. Here's mine with the wingnuts on the bottom...

Edited by s p a c e m a n on Thursday 24th November 12:51

[ChimpOnGas]

Excellent chaps, TBH I was always taught to do the job right it's best to avoid being lazy and avoid the temptation of looking for short cuts, because invariably it works out faster just to remove the obstructing part to gain better access rather than spending hours struggling to work around them. In truth what seems like a good cheat on paper can often result in more frustrations and time spent on the job than if I'd just tackled it properly, in this case "properly" means I really should stop being lazy and whip the rad out.

Saying that if I can wrestle the cowls and fans free from the car without pulling the rad it would potentially be a much faster and easier job so I'll have a go at the lower cowl bolts with a ratchet ring spanner and see where it takes me as there really isn't anything to lose trying this first. As the new rad (with cowls) were fitted only 18 months ago I'm hoping I'll get lucky and find all four bolts come out without too much of a fight? It's got to be worth a shot before I decide on the hole drilling idea or a full rad out approach... which if I'm honest with myself is really the proper way to do it.

The truth is I never learn, so place your bets now chaps, there's a very good chance I'll waste a morning faffing about with cowl bolts only to end up realising I should have just pulled the rad out in the first place

s p a c e m a n said:

You can easily remove the bottom cowling bolts with a spanner with the rad in place as long as they're not corroded, couple of turns to get them loose and then undothe rest with your fingers. I've done it a couple of times because my rad is slightly bigger than standard so it helped give me some more wiggle room. Putting them back in will be a faff though.

Mine aren't joined in the middle, you should be able to remove the nearside one on its own, the other is a pig because of the pipe on the bottom. Here's mine with the wingnuts on the bottom...

Thanks s p a c e m a n, a very helpful response and photo mate


It's probably a stupid question, but is there any reason why I couldn't just remove my sick N/S fan by simply removing the four arrowed bolts?



Dave.

[s p a c e m a n]

I'm going from memory here, I think that it's just an 8mm nut with a spring washer on the other end of those bolts so you need a hand behind to undo them.

Thinking about it, that would be more of an elegant design solution than my wingnut thing. Find a way to fix the nut to the back of the fan cowling so that you can just undo the bolts that hold the fan in place. I think that it was a penny washer, a spring washer and a small lock nut back there. A dolop of glue would probably hold them into place and then you would be able to just remove the fans from the cowlings without touching anything else.

Edited by s p a c e m a n on Thursday 24th November 14:52

[ChimpOnGas]

What a shame they never thought to used captive nuts