Coolant Leak. Housing Temp Unit?

[Spool]

Hello all.

First off. I appreciate all of you, it's been a pleasure learning here.

73' C20 and I've had a coolant leak for sometime that I need to fix.
It appears to be leaking at the housing temperature unit, which makes a slow mess of my block.

I'm trying to determine if this is something a learning novice like myself could do without damaging anything severely if I made a mistake.

If I do decide it's the housing temp unit and repair it myself, I'd have to learn how to flush the coolant system, preferably replace the heater core and fresh hoses through-out while I'm at it and
learn how much coolant the system takes total when I'm done.

Any insight would be much appreciated as always.

There's this one video that helped me a great deal for the heater core which is this one :
https://www.youtube.com/watch?v=M9SIafVsqyc

But of course the priority here is to stop the leak; I'm just reaching ahead thinking It'd be wise to do it all once the coolant was drained.
Yet, is it as easy as draining the coolant, and swapping housing temp units?

-Thomas

[VileZambonie]

Just replace the thermostat and gasket, top off the coolant.

[blazer74]

I had this for a while, it was super slow and would make a small puddle of antifreeze on the intake, could never see it happen tho, it would just appear.
Ended up replacing the housing after trying a new gasket.
If you do need to replace the housing get a good one not a cheap chrome pot metal one.

[Spool]

Hey Blazer.
Nice to hear a similar issue occurred.

You drained the system and then simply swapped the unit?
Did you find anything in the process or was it straight-forward?

Any luck cleaning your engine block off after wards?

Thanks.
-Thomas.

[blazer74]

It's at the top of the engine so just drain enough to be below that level.
Unless you need to replace the coolant any ways.
2 bolts hold it on and u have the alternator bracket on top of the neck that needs to come off.
Just clean off the old gasket without damaging the surface of the intake manifold.
New thermostat while u are there also.
Just a (transparent )smear of silicone sealer on the gasket if u like.

[Irish_Alley]

you would have to inspect it more but you can clearly see the hose is bad. it might be leaking and running down the thermostat housing

[Spool]

That's a great idea. I'll swap the hose first to see.

Thanks Irish.

[Irish_Alley]

if you cant see a trail from the water on the housing i wouldnt just change the hose. only if you see the water trail or can feel it getting wet then and only then would i only change the hose

[Spool]

you would have to inspect it more but you can clearly see the hose is bad. it might be leaking and running down the thermostat housing

I'll take a look.

[75gmck25]

My truck sometimes develops a little seepage near the end of that radiator hose and it leaves a small puddle on the intake.  I have found that if I already have a good hose (yours looks a little questionable), all I need to do is tighten the clamp down about 1/2 turn and it solves the leak.

It seems that most replacement hoses for these older trucks have a fairly wide tolerance, and the old style worm clamps don't always pull the "loose" hoses down evenly.  If you have ever replaced a radiator hose on a newer Japanese car, or one of the newer Fords you will find that you need a liberal application of WD-40 just to get the hose to even slip on the fitting.   The hose fits so tight that it seems like it might not even go on the fitting.  Then they use a newer style clamp that gives better clamping around the entire circumference of the fitting.

Bruce

[Monkey Uncle]

My truck sometimes develops a little seepage near the end of that radiator hose and it leaves a small puddle on the intake.  I have found that if I already have a good hose (yours looks a little questionable), all I need to do is tighten the clamp down about 1/2 turn and it solves the leak.

It seems that most replacement hoses for these older trucks have a fairly wide tolerance, and the old style worm clamps don't always pull the "loose" hoses down evenly.  If you have ever replaced a radiator hose on a newer Japanese car, or one of the newer Fords you will find that you need a liberal application of WD-40 just to get the hose to even slip on the fitting.   The hose fits so tight that it seems like it might not even go on the fitting.  Then they use a newer style clamp that gives better clamping around the entire circumference of the fitting.

Bruce

Yep, I had the same leak.  Just a slightly loose hose clamp.

[hatzie]

That hose is spent.  It shouldn't be swelled.  If it isn't leaking yet it will be.
I put a very thin layer of Sil-Glyde silicone grease on the inside of the hose and the outside of the fitting.  Silicone grease will not eat the hose and it will keep the hose from bonding to the fittings.  The clamp will hold the hose from sliding over the raised bead on the fitting.  If the raised bead is chewed off from corrosion, or just a cheap nasty fitting that never had one, replace the fitting.
I use Breeze Liner hose clamps...  They have a strip of stainless band inside to protect the hose from the worm slots in the outer band so the hose doesn't extrude through the clamp slots and loosen up.

I also use Fel Pro 35562T water neck gaskets with a Neoprene O-Ring bonded to the gasket felt... no sealer is needed and they don't leak as long as the gasket surface on the intake and the bottom of the water neck are flat and not excessively corroded.