I'm in the "while I'm in there stage" and decided to replace the heater core lines.
Yikes. Nasty.
I'm tempted to cut off the end of the tube where it is corroded.
Since the hose goes so far down the tubes, is that a good idea?
I've seen mentions of Gates 28477 hose but these appear to be 3/4" on the tube side and 5/8 on the heater core side. Is that correct?
If so do I need to order proper lines from Wilkinson's?
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That engine has been running with a shut-off valve or two in the heater lines. The Pantera heater valve can be adjusted to either -A- shut off hot water thru the core completely and open half-way in the winter, or -B- open all the way in winter for heater & defroster, and closes only half-way, so the heater is always at least partially on. There are two different valves and they both act the same way.
Most of us put mechanical shut-off valves in for safety (the short rubber hoses that connect them are infamous for rupturing under the dash at high rpms, and to improve A/C performance, but we open them occasionally so cooling crud doesn't build up.
To replace the stock 50-year old steel lines, you'll need to pull the drivers seat and the entire console and cut the lines to remove. SS is recommended so this never happens again.
Thanks Boss.
I've ordered ball valves to install in the engine compartment heater hoses. Are you saying I need to pull the tubes and replace them completely?
Does anyone know if the stainless replacements from Pantera Performance mentioned here: https://pantera.infopop.cc/top...-replacement-success are still available?
The stock heater lines are the same untreated mild steel as the main water lines, so don't be surprised if the engine ends are also messed up. The sheet metal spigot(s) in the engine are usually shot, too. BTW, they're pressed in, not threaded. Put a slug in the end so they don't collapse and you can lever them out with Vice Grips.
Whether you clean the lines out or chop them off, you'll likely find the last few inches are corroded to transparency on both ends. These days I tend to go for permanent solutions rather than temporary, hence my stainless steel recommendation. That's why I made ss engine spigots on my lathe. Brass would also work.
A little update. I cut off the very end of the driver's side tube at the heater control valve and the tube itself was in very good condition. I cleaned off the tube ends, sanded them to bare metal and painted them with POR15.
Installed silicone 5/8 to 3/4 hose from Pegasus.
The left side worked perfectly. The right side (5/8 to 3/4 90degree) was too loose on the heater valve. It seems it's less than 5/8. So I've ordered a 1/2 to 5/8 reducer and will try that.
I removed one of the hoses on the engine side and checked the tube and it too looked good. Reinstalling that hose (it's new from the restoration) was one of the most difficult and painful things I've done in a while.
Good move on the silicone adapters. I have also moved into the future and on my reassembly of 2511 every hose is silicone, with the exception of fuel, of course.
there is a seemingly endless selection of adapters such as you used, and multiple elbows also available.
A standard worm drive hose clamp can cut into the soft silicone hose and special lined clamps are recommended. For the larger sizes I always use a lined T-bolt clamp.
Larry
Yep! I'm a huge fan of these lined hose clamps:
https://www.pegasusautoracing....ion.asp?Product=3613
I like Oetikers too. KTM motorcycle thing 
Here's how it ended up.
Yes, definitely doing it the hard way.
the left pipe was easy, 5/8 to 3/4 silicone.
The right pipe is 1/2 to 5/8 silicon to 5/8 barb to 1/2"NPT male - female elbow - 1/2 NPT male to 3/4 male barb to silicone hose.
I ran out of lined hose clamps, may replace those three later.
