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Cooling System Overhaul - Stumped and Frustrated

Either 5/8" or 3/4" I'm sure (edit: or not...that would be hose size, d'oh!). Only comment I can find is that the one on the pump that is the "inlet" is 3/4", can't find any reference that is from a manufacturer stating the sizes of the fittings.

May need to use a 45 or 90* fitting at this location to clear things, but that is a lot easier to run than a ton of adapters.

Edit: and I just saw a comment that 5/8" NPT doesn't exist, so maybe it IS 3/4".
 
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I wanna say it's 1/2npt. Keeping in mind that with npt threads, the named size does not indicate the diameter of the threads. Just look at your 1/8th npt stuff. It's around a 1/4" diameter. You can get those threaded pieces from the home improvement store in the brass section, or if you can't find them there, they do have them at the parts store but they are usually in the chrome section...
 
You may be right, good call. They seem large, but the NPT stuff is not intuitive in that respect, at least to me. If I'm in doubt, I always just take something that fits the threads with me to the store.
 
Had the parts store pull a pump. Its 1/2 in NPT.

Got a short 1/2 NPT to 3/4" hose barb fitting. Should work nicely.

Thanks for the idea guys!
 
diesel4me said:
Would a 3/4" NPT to 1/8" NPT bushing like this work?..you can get 3/4" female NPT barbed fittings that will screw over the bushing..
Click to expand...

Thats basically what i've got rigged up now, and it leaks. Nervous to tighten down the 1/8" NPT into aluminum fitting any further.
 
You use teflon tape on the threads? Careful, if the teflon tape came from the same country as your radiator, it may not actually be teflon based on reports I've read, lol.

Shouldn't need it with NPT, but this is chinese crap we are talking about.
 
dyeager535 said:
You use teflon tape on the threads? Careful, if the teflon tape came from the same country as your radiator, it may not actually be teflon based on reports I've read, lol.

Shouldn't need it with NPT, but this is chinese crap we are talking about.
Click to expand...

For pipe threads, I went raw w/o teflon.

That was probably stupid. Although, this new approach sounds like a better one.
 
I usually use Rectorseal on NPT threads,or maybe Permatex #1 or #2 if I have that handy...non hardening is probably better,wont give grief later on if its needs to be taken back apart..

I've had teflon tape get into things I wished it hadn't,and it sometimes insulates the connection so a electrical sending unit wont ground,and cause problems--I'll use it if thats all I have handy,but prefer liquid or paste sealer..

Pipe threads being tapered,dont really need to be cranked down all that tight to seal--in fact,too tight spreads the fittings and can make it leak!..you need to know "when" ,when you tighten them up..especially if the fittings are soft stuff like brass or aluminum..
 
Oh Ya things can happen. But it's never a good start to have a crimp seal on the tanks. That's just asking for trouble.

Don't use pipe tape. Use any kind of pst. The white paste on pipe threads. And you don't need to drown it. Leave the first 2-3 threads clean.
 
ARP sells a non-hardening white paste/teflon product as a thread sealer, is anything sold as a non-hardening thread sealer going to be pretty much the same thing?

Happened to find some non-hardening thread sealer on clearance and picked up some tubes, but the ARP stuff is more explicit about the temps and pressures it will withstand on the package than what I got.
 
Dumb heater hose question.

On the trucks with just standard heat, and no rear heat, the hoses go from manifold to heater core, then heater core to radiator (or water pump), correct? No heater flow valves, etc?

Mine had the burb rear heater at one point, but the valves/splitters were still in tact, but capped in some half ass way. Decided to bypass it all while I was running new hoses.

Can someone confirm there are no underhood valves in the standard setup?
 
I've never seen it personally, but I've seen the valve listed in the parts catalogs for non-rear heat vehicles. Not saying the parts lsitings are correct, but they are there.

To piggyback with you, I'd like to see a C/K/R/V setup with the valve in place. On the Olds motors in the 1980's they ran a heater valve, it was threaded into the intake, and fed the heater core that way.
 
I'm not sure if it was standard or not, as opposed to being an early/late thing, or even perhaps dependent on what heating setup.

I should look at my '87 to see if it has a valve, but the hood is covered with junk lol.
 
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