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a couple a quick cooling questions.

blazinzuk

blazinzuk

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So cooling issues. Yesterday started hearing a new noise. Fan clutch failure. Auto parts store all had the same clutch. Smaller in diameter than mine and thinner. My original one is much larger.

Does anyone have a part number for the larger clutch?

Second question. The overflow for the radiator. The cap on it does it need to be vented or sealed?

I have installed the smaller clutch ( not at home gotta get home) and the motor is running about 20° hotter than normal. Always under the 200 mark before and now it is above the 200 mark by a bit.

Need to get home first then I will worry about fixing it or swapping in windstar fans etc

BTW this is all on my 89 jimmy with a 6.2
 
Overflow on mine is vented to the atmosphere. A bit of "baffling" in the design to try and keep fluid from sloshing out, but does not contain pressure.

Not to be condescending, you probably already know this, but since we are talking about cooling systems and an issue...the radiator cap vents into the overflow at whatever pressure its rated at (theoretically, so likely 15-16PSI in most of our setups), generally as the engine heats up and the coolant expands. Since the radiator cap is the highest point in our trucks cooling system, any air in the system will be purged into the overflow first, then fluid. If pressure is below the cap rated pressure, nothing is "vented".

Once the pressure drops in the cooling system as the temp goes down, there will be a vacuum formed, and the radiator cap allows coolant to be pulled back in from the bottom of the reservoir, thus why you don't need to open the radiator to top it off. If the cap on the reservoir was sealed, it would explode and/or implode. I don't think it would take much with these reservoirs. :)

I just checked Rockauto, they list AC Delco part 154911 as the severe duty AC Delco replacement, but the aftermarket severe duty ones look to have a more substantial housing and I generally do not trust the online parts listings. I can check my GM parts manual if you like, but no idea if the part number will cross correctly.

Interestingly I see one listed is marked as "reverse rotation" which I assume means their listing is wrong (I chose 6.2L as the engine) and it's the TBI one. Any chance they sold you the TBI reverse rotation clutch? Since your temp went up with that one change only, that or the clutch not working properly out of the box are the only two I can think of. I do not know if the fans were larger or smaller based on the clutch. Perhaps they will slip if the load is greater on the lighter duty clutches?

This is what Rockauto lists as the Delco Severe duty: http://www.rockauto.com/catalog/moreinfo.php?pk=339758&cc=1061547&jnid=479&jpid=6

this is a randomly selected aftermarket severe duty http://www.rockauto.com/catalog/moreinfo.php?pk=815273&cc=1061547&jnid=479&jpid=4

I do note that some reference a 10MM mounting bolt, and the rest state 5/16".
 
The reason I asked was to see if I could find a different part number. The auto parts stores mostly just have the one you listed.

Yah I figured the cap would be vented because of how a cooling system acts.

Just making sure I have all my ducks in a row. My drive home is not easy on the Jimmy. 3 passes that are about 6% grades for a couple miles
 
Standard rotation?

If yes, shop for a clutch for an 83 K30 dually, 454, 4spd WITH 4.56 gears. The gears make a difference.
 
Do you want all the part numbers listed at rockauto, if you can't access it now?

Do you happen to know if the bolts are 10MM or 5/16? My guess is the TBI is 10MM, the 6.2L was 5/16".

From what I can tell of the cross reference at AC Delco.com, the AC number I gave above is for VIN "C" Diesels only from '88-91. No idea if that was the only diesel VIN then or not.

I found this on AC Delco.com

Engine Cooling Fan Clutch
Part Number: 15-4950
Product Notes:
Engine Cooling Fan Clutch
Hvy Duty RAD & TRANS OIL CLR(V02) ; Exc AC MAN CONT(C60) ; CODE HT,AW, 1 Per Veh

Per Vehicle: 1; Years: 1988-1991


CLUTCH ASM-FAN BLADE
Part Number: 15-4599
Product Notes:
Engine Cooling Fan Clutch
AC MAN CONT(C60), PROVISION FOR HD TRAILER EQUIP(Z82) ; CODE DT ; ; THERMOSTATIC ; 1 Per Veh

Per Vehicle: 1; Years: 1988-1991

One is rightside up, the other is upside down in the photos, so that isn't much help, but it appears that 15-4950 has no gaps between any of the fins on the "front" of the clutch, where 15-4599 does have some large gaps. On the 15-4950 there may be large blocks of aluminum where there are gaps on the 15-4599. Here is the image for 4950: http://images.wrenchead.com/smartpages/partinfo_resize/DCL/15-4950_Primary.jpg here is 4599 http://images.wrenchead.com/smartpages/partinfo_resize/DCL/15-4599_Primary.jpg

Not sure those are anything really indicative, just the only differences I could readily see.

This surprises me: No gas applications are shown as an interchange for either of the above clutches. 6.2L diesel only, from 1982-on. VIN C or J, depending.
 
No I can look at rock auto. Just was wondering if someone had the number.

I will see what the 83 one ton gets me
 
Straight out of the GM parts manual:
1987-89
6.2L VIN C
1/2 ton R/V

W/AC; W/O Trailering Package (RPO Z82): 14032395 (does not cross @ ACdelco.com)

Same but W/RPO Z82: 14050448 (crosses to 15-4599 on ACdelco.com)

With auto trans, without AC, with heavy duty cooling (RPO V02) 14061688 (does not cross @ ACdelco.com)

All GM part numbers appear to be discontinued, although they may have changed. Doesn't help, I know, but does show that original configuration of vehicle could net you one of at least three different fan clutches.

If you can check the fan or clutch, can't tell which (if you care) there may be a two or three digit code stamped or painted on it somewhere...looks like they all either start with "A" or "D". All D codes are two digit, A could be two or three digits. Apparently that code is tied to specific clutch part number.

The junk you learn...lol
 
Back when I lived in Phoenix I'd get the fan clutches sold as heavy duty cooling. They are usually thicker. I have noticed even the factory replacements.have gotten thinner a bit.

I actually have one here I just took off the truck as I don't need that level of cooling anymore.
 
4xcrazy said:
Back when I lived in Phoenix I'd get the fan clutches sold as heavy duty cooling. They are usually thicker. I have noticed even the factory replacements.have gotten thinner a bit.

I actually have one here I just took off the truck as I don't need that level of cooling anymore.
Click to expand...


The big one? How much you want for it. I gotta get my cooling back we are gonna be moving soon and working on our new house and that means the Jimmy is gonna be hauling a trailer alot
 
Is the 6.2 vs gas bolt pattern the same? If so, I think I still have my old HD cooling clutch.
 
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