News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

fan clutch inspection...

Started by Steve W, July 27, 2015, 08:35:05 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Steve W

Car still running warmer than should be. Read up on the fan clutch. When the car is fully warmed up,,,and I turn the engine off...it still spins a few revs before stopping. Also I can turn the fan blades very easily by hand. This means the fan clutch is bad?

Also, from what I've read, I should have a 5 or 7 blade fan. I have a six blade fan! Is that a replacement fan?
Steve Waddington
1968 Coupe deVille
North Hollywood, CA
CLC Member # 32866

Scot Minesinger

A bad fan clutch can take out a water pump.  If there is any vibration when car is in park and engine speed increased, that will go away if fan belt is removed briefly when car is cold means clutch is ready to go.  Not sure about the keeps spinning thing, not sure that is a problem.

On the fan blade itself if you look in the shop manual you can tell if it is replaced or not.

The car used to run cool and now it does not as I understand after replacing water pump and radiator, so doubt the fan is an issue.  Look at the seal around the radiator to fan shroud comparing existing to replacement.  If there is a lot of room for air to pass around rather than thru the radiator that is a problem.  Do you have the rubber radiator splash protector sheet installed?  If there is a big gap around radiator and shroud it can be sealed with strips of rubber.

It is never easy is it?
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

TJ Hopland

The fan spinning a few revs after you shut off the engine is a sign of a problem.  There are seals on those that eventually let some of the fluid leak out which then effects how well it works.  Fully warmed up especially on a warmer day it should be well under 1 turn when you shut it off.   It is normal to be able to turn it fairly easy by hand, part of how it works has to do with centrifugal force from the turning putting the fluid where it needs to be to do its thing.   They are not that expensive and usually not hard to get since they fit a ton of vehicles.   Cadillac's appeared to always use the 'heavy duty' option plus that version is easy to modify to kick in a little sooner if you want to. 

You will be amazed at the difference when you replace it.   If you have fairly quiet exhaust you will likely hear it roar for a few seconds when you first start it up cold on cooler days.   On a new tight clutch it takes a few seconds for the fluid to distribute and warm up so it can slip properly when its cooler.

One other thing I have heard but not sure if its true or not is a working clutch can actually freewheel if the ram air effect from driving is faster than the fan so you get even more cooling.   Again not sure if that is true but the last one I replaced it seemed like it went down a few degrees on the highway.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Steve W

It's the highway/freeway temps I'm most concerned with at this point. Around town today, at 90* or so, it was a little warm, Got on the freeway thinking it would cool down a little at higher speeds, and it actually got warmer...all the way to the 3/4 mark on the temp gauge. Got off the fwy...temps started going down...to the half-way mark, which is about normal for my car in the summer. So that made me suspect the fan clutch.
Steve Waddington
1968 Coupe deVille
North Hollywood, CA
CLC Member # 32866

Scot Minesinger

The fan clutch engages at idle and at high speed disengages.  Hot running on highway does not indicate fan clutch problem.  It sounds like your timing is wrong if it gets hot on the highway.  Either advanced or retarded timing will cause a hotter running car than normal at high speed.  Did you set the timing to factory spec with car in drive, brake on, vacuum hose plugged and off distributor vacuum actuator, and at specified RPM?  Your clutch could be going bad, but on the highway that should not matter.  Also make sure all of the air go thru radiator and not around it.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Caddyholic

I had a similar problem on my 61 it was the generator over charging the battery. At higher engine speeds the voltage was over 15v. This through off the scale of the temp gauge. The car engine was not hot just indicated it was. As soon as  it went down to idle the voltage went down to 12v and the gauge went down to normal. Check your charging system.
I got myself a Cadillac but I can't afford the gasoline (AC/DC Down Payment Blues)

1961 Series 62 Convertible Coupe http://bit.ly/1RCYsVZ
1962 Coupe Deville

cadman56

Steve,
How old is the thermostat?  Do you have a partially restricted exhaust system?
When is the last time the radiator was pulled & cleaned or rodded out?
And the fan clutch should not let the fan blade free-wheel when shutting down the engine. 
Check all the basics as mentioned above.
Good luck, Larry
1956 Cadillac Coupe deVille (sold)
1956 Cadillac Convertible (sold)
1956 Cadillac Eldorado Seville (sold)
1967 Cadillac Eldorado (sold)
1968 Cadillac Convertible (Sold)
1991 Cadillac Fleetwood Brougham dElegance
Larry Blanchard CLC #5820

Steve W

Well...installed the new fan clutch today...took the car for a half-hour drive...91-95* outside today at 5:30-6:00pm. Yeah, it's hot here in the Valley (So  Cal).
Around town...on freeway...all over...temp needle never went more than the half-way mark! That makes me happy! And no pinging...stomped on the gas a few times and popped it into passing gear...just smooth Cadillac power with no fuss!

But, yes, I can really hear the fan working! Its loud! I never heard the other one at all.

I know I still need a new radiator (I have no idea how old this one is, but it still has the original fittings from the transmission...no adapters or hoses). And it has a tiny leak somewhere. And then I'll probably see even cooler temps.

So far:
New t-stat
new water pump
new fan clutch
new hoses
timing re-set to 6* btdc. in drive with vac blocked off, at idle (manual calls for 5*, but a the mechanic that rebuilt my dizzy and new vac adv and installed the Pertronix said that 6* is prob best because I can't get anything higher than 91 octane, and I'm running Pertronix).

I have the orig fan shroud intact and all the front astromat stuff (but not at the sides by the headers, if it was ever there.)

Where should I aim the little I.R. gun to get the most accurate temp reading? One that would tell me the approximate degrees my temp gauge is trying to tell me when it gets to 1/2 way.

When I came home from my little trip, I popped the hood and aimed the I.R. gun at the top of the radiator just where the hose comes in from the thermostat...not at the hose, but at the metal housing. It read 212-ish degrees. I tried to point it at the t stat housing, but its kinda buried my the ac comp...but it read 190-195-ish.
Steve Waddington
1968 Coupe deVille
North Hollywood, CA
CLC Member # 32866

TJ Hopland

Those are good places to point the temp gun and those are good readings. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

Julien Abrahams

I thought that a failing fan clutch would result in a car running hot in slow traffic when air flow is minimal. I believed that the fan clutch should not have a direct influence on engine temp when traveling at higher speeds when the movement of the car causes enough air flow through the radiator? But now I'm not so sure about that anymore.
1954 Cadillac series 62
1967 Cadillac Sedan De Ville HT
1969 Austin Healey Sprite
1979 Opel Kadett

Scot Minesinger

Julien,

My thoughts as well, fan clutch disengages (the whole point of having it in the first place) at high speed.  Generally highway speed cooling issues are timing, thermostat (especially if you do not have the right one that covers by-pass when open all the way), water pump or air not flowing thru radiator.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

cadman56

Dear all,
A partially restricted radiator (inside water flow) will greatly decrease the cooling efficiency They 'cake' up with mineral deposits inside all the cooling tubes.
It is correct to say a the fan probably should not be engaged at highway speeds, however why do the better ones include temperature activation?  On several of my cars I can hear the fan engage & disengage while on the highway, especially when using the AC.
Glad to see you are running ok now, but certainly think about getting the radiator out & rodded out or cleaned later.
Larry
1956 Cadillac Coupe deVille (sold)
1956 Cadillac Convertible (sold)
1956 Cadillac Eldorado Seville (sold)
1967 Cadillac Eldorado (sold)
1968 Cadillac Convertible (Sold)
1991 Cadillac Fleetwood Brougham dElegance
Larry Blanchard CLC #5820

Glen

Do not forget the lower radiator hose.  If it collapses due to the suction of the water pump you will have the problem of engine overheating at highway speeds. 

Easy check is to squeeze it by hand.  If you can do that it probably needs the spiral wire insert replaced.   

 
Glen Houlton CLC #727 
CLCMRC benefactor #104

Scot Minesinger

The radiator lower hose collapsing is another way a car will run too hot on the highway.  Another one is if the exhaust is substantially restricted due to internal rust of muffler and debris clogging.  Runs cool and nice at low speed and too hot when on the highway with substantial partial clog in exhaust - also gas mileage is not as good.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Steve W

Lower radiator hose is ok,,,and the spring inside is ok too. In fact, all the hose have been replaced within the last 18 months.
However, my muffler is somewhat slightly "crunched". I never thought about it actually restricting exhaust flow. It was like that when I bought it, just kinda bent up. Not leaking and its very quiet, so I couldn't justify spending the $ to replace it. Hmmmm....
Steve Waddington
1968 Coupe deVille
North Hollywood, CA
CLC Member # 32866

chrisntam

Quote from: Glen on July 31, 2015, 02:03:34 AM
snip... 

Easy check is to squeeze it by hand.  If you can do that it probably needs the spiral wire insert replaced.   



When I purchased (Rock Auto)my lower hose about a year ago, it didn't have the wire insert in it.  I was surprised it wasn't there.  I took the old one out of the old hose and inserted it into the new hose.    I recently purchased a replacement hose (Rock Auto again) and the insert isn't in that one either.   >:(

What's up with that?, it's a Gates hose, which is name brand.
1970 Deville Convertible 
Dallas, Texas

TJ Hopland

Sometime in the late 80's or early 90's they stopped putting the wire in the hoses.  The current designs are supposed to be stiff enough that they don't collapse.  I think it has to do with the way they are made along with the improved materials.   I have not had issues.   The few times I have seen a hose collapse there have been other issues in the system.   
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason