Radiator surprise!

[Mel Fuelling]

I believe I just avoided a walk home. I removed my fan and

shroud for the winter and noticed a damp place around the

lower radiator hose outlet. Hoping for a bad lower hose, I

drained the coolant and removed the lower hose. When I

wiggled the lower hose to remove it, I thought I could see a

distinct circle of green at the junction of the radiator tank and

the hose outlet! I took the hose off, it looked terrific.



Then I removed the radiator and found the solder joint on the

bottom outlet to have a nearly complete fracture around its

circumference! I buffed the brass surrounding the joint with a

wire wheel in a drill until I had bright metal, found a position

to support the radiator securely, and built up a lot of solder

around the outlet to add mecanical support to the outlet. I

pressure tested it with a motorcycle tube cut and clamped to

the upper and lower outlets(it will only generate 3-5psi), resolder

ed 2 pinholes and reinstalled it. Its running dry so far after

about 400 miles.



I believe that the trucks that have the crossflow radiator like

mine with the short lower hose may be prone to fractures, leaks,

and eventually blowing the outlet out of the bottom of the right

side tank, because there is such a violent engine shake at shutdown, coupled to the lower outlet by a short and relatively

stiff hose that the lower outlet is stressed much more than most.



I may be wrong in my suspicions, but I'm sure going to pull

my radiator shroud loose at the bottom so that I can take a good

look at my lower outlet at least a couple of times a year from now

on! (I had recently noticed my surge tank losing about a pint over

the last 4 weeks, but no green puddles or other signs of coolant

loss)

 

[Pit Bull]

Mel good info. Also good idea with the motorcycle tube for presure testing. Sounds like you would be a good guy to have around on that surviver TV show

 

[DieselBuzz]

Hey Mel,

What's the trick to getting the fan off the pulley?

Art

 

[Mel Fuelling]

DieselBuzz,

I've used a 1 1/2"(I think) openend on the left-hand fan nut, with a LARGE channel lock

pliers to hold the edge of the serpentine pulley, but that leaves

scars on the pulley and the leather pad I tried slipped, wouldn't

hold. I was afraid further scarring would damage the belt.



I have an 18" rocker-head prybar that has the end of the handle

sharpened like a center punch. Setting it about 3/16" away from

a hex edge on the nut, holding an angle to drive the nut, and

striking a pretty solid shot with a 2# hammer seems to be an

excellent way to both loosen and tighten the nut. However, this

puts quite a dent in the nut.



I wish I had a good way to hold the pulley. I believe I read a

thread about a chain wrench. The shop manual says use a

screwdriver to engage the bolt heads on the pulley( I couldn't

get anywhere that way. )



Pull the clips on the fan shroud and lift it up and back to get to

the fan easier. After you remove the fan, take the shroud out

and store it too. That will let you take a good look at the bottom

radiator outlet to make sure its not starting to leak.



With Lund winter front inserts in all year round, I don't see any

increased operating temps until ambient high temps reach 60-65

degrees F. That's a work truck weighing 8300# ocassionally pulling a 6,000# trailer. Just don't walk off and let it idle for 2 hrs.

on a hot day. At 70 degrees the operating temp on mine goes up

quicker at idle than when the vehicle is pulling a trailer down the

road.

 

[brkoyle]

The easiest way to hold the pulley is to fabricate a bar that is used to hold the pulley. Use a 1" by 1/8" by 24" piece of scrap steel. Drill two holes in the steel bar that correspond to the bolt pattern of the pulley. You will then need two longer bolts to attach the bar to the pulley. Then you will have to use whatever means that you can to loosen the 36mm fan nut. I went to the local hardware store and bought a shorty wrench and then used a cheater bar. You may have to reduce the thickness of the wrench to be able to slide the wrench where it needs to go.



Bruce

 

[Tim1]

Hey Bruce, that flatbar is a good idea. I took a 1\4 punch and drove it towards the drivers side, came right off. It's a 1 7\16" open end that I got from harbor freight. Long winded sucker! I usad the barring tool to hold things as I was doing the dowell pin fix. Tim

 

[Mel Fuelling]

Bruce,

Excellent solution! Sometimes a little thoughtful field expedience

is just as effective as having your SnapOn truck on speed dial, not

to mention a whole lot less expensive!

 

[Dale Reed]

The about 1. 5 inch diameter rubber pads below my radiator are cracked and looking kinda useless. Should these be replaced with new ones? I can't see that they actually do anything.

 

[DieselBuzz]

I had a feeling that fan nut was going to be harder than it looked!

Art

 

[CrewCabDiesel]

Have anyone tried the strap wrench from Sears to hold the fan pully ? It looks like it might work well for that job.

 

[84 crewcab]

Tools are Cool

I purchased the tools to do this recently. Both were from OTC and cost just under $100. I purchased the strap wrench and the oversized thin fan wrench. I was able to get the fan clutch off without this stuff, but I wanted it to aid in doing what Mel is doing and remove the fan in the winter, every winter. I haven't tried them out yet as the final mocdifications are not completed for my conversion.

 

[ageorge]

fan removal-- what's next

A word or two to the wise. When you put that fan back on next spring, please be sure to give the fan nut a real good tightening. If you don't, when you shut the key off for the first time after reinstalling the fan the fan may unthread itself and do serious damage to the radiator . I learned the hard way on an 89 I had a few years ago.