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I am amazed with all the help you guys have given me ... my nextproject is to replace the heater core ... i am only getting a very few drops onthe outside of the car when i park it right under where the core is ... usually the heater core leaks inside thecar ... anyway unless anyone has any ideas of what could be causing the slightdrip i will replace the core because i dont want to run into a major leakinside the car ... does anyone have any suggestions on what exactly i will orshould replace while doing the core? .. should i replace the valve or can itjust be cleaned up? ... what other parts are necessary for the job as i want toorder whatever i will need asap .. also any suggestions on where to get goodquality parts for this job? ... thanks again for all the help
1) You can get shutoff valves 3/4" and 5/8" inch respectively and splice them into the heater hoses in the engine bay under the fenders and that will stop your leak if and until you're ready to deal with the heater. I have the part numbers if you choose to do that.
2) Many folks mistakenly replace the copper elbow under the dash with a plumbing store fixture that is guaranteed to leak - you need the RIGHT elbow from Paragon -- so check that first. (Bottom center item in the parts picture). It HAS to have the flanges on it!
3) If your heater has the original silver capillary tube - carefully remove it and keep it...the repro heater control valves don't use it (its unnecessary) but many chose to keep it and reroute it in a faked manner for originality. I kept mine.
4) Make sure your hose clamps under the dash are tight and correct, they should be Corbin clamps - if you mess with them get yourself a set of swivel head Corbin clamp pliers - it'll save you a lot of cussin'
5) Do NOT twist and force any hose connections on to their nipples, they break loose easily. A little slathering of silicone inside the hose ends and some patience will help you slide them on;
6) Read the attached article by Dave Z.
This should be enough to get you going
Last edited by Frankie the Fink; 02-01-2017 at 04:40 PM.
Please take Franks advice on the elbow. I originally used a plumbing elbow on mine after a frame off restoration. My wife had joined me on a few rides before this incident: While returning from a Sunday morning Cars and Coffee event I pulled into my drive way and the pressure from the cooling system forced the heater hose off of the plumbing elbow pouring scalding hot water all over the passenger compartment carpet. Had my wife been in the car the burns to her legs would have been severe.
Some vendors actually supply the plumbing elbow when you order this part. If they do return it and be sure to get the correct one with the lip on both ends. I also removed the corbin clamps and used worms screw clamps.
The heater core and the hose connections to it are completely inside the car. If coolant is leaking onto the ground, then any leak isn't from the heater core.
You'll get off lucky if its just the hoses, but yes...the heater core is contained completely inside the cockpit... If you change the hoses the above advice about clamps, pliers and elbows still applies...as they terminate inside the cockpit as well.
There may be pressure on both sides, obviously more on the discharge side of pump. The system has up to ~13 psi.
On 2nd thought - I think you're right. Since the entire system is under pressure, any leaks in the core would continue to leak...
Good thinking Frankie!
(I'm in the middle of this job right now)
PS: To the OP: The connection on the RETURN line from the core is actually INSIDE the firewall.. but the SEND (to core) line connection is just OUTSIDE the firewall.
The shut off valve is a great idea. If and when the 50 year old heater core on my 67 gives up I'm not sure I'll tear the dash apart to replace it. I never use the heater since I don't drive the car in the winter.
I'm moving along on this project. Just one correction to the PDF posted above that I encountered...
The gasket is shown in the wrong place on the photo where all the parts are in order.
The gasket should go between the heater box and the temp valve bracket... not between the blower housing and the bracket, as implied by the photo.
Seems minor -- until you realize that the entire unit is grounded via the temp control cable jacket. With that gasket in that position, it blocks the ground from getting to the motor. After careful examination, the gasket is needed in the other location as there are small offsets around the bolt holes.. without the gasket in this position, cold air can get pulled into the fan.
Don't forget to have your new heater core and temp control valve tested at a radiator shop. Imaging going through all that work and then finding out you had a manufacturing flaw that caused another leak.
I learned this trick from JohnZ.
And yes, I had a bad soldering joint on my temp control valve. Thank you John.
Yes - I had the assembly pressure tested at a local shop...
Thank you JohnZ!
I've got the core installed - just waiting on some part to arrive to finish the project. Control cables and switch..
One 'issue' I see is that the temp control cable 'snaps back' when I pull it out...????? Any idea what creates the resistance to hold in in place?
The heater core and the hose connections to it are completely inside the car. If coolant is leaking onto the ground, then any leak isn't from the heater core.
My 59 heater decided yesterday at a WSCC show at Blackhawk Museum to let loose yesterday just as I ended a 40 mile drive to get there so I count myself lucky.
Soaked the carpet and a torrent of water also ran under car. Fortunately I do not run antifreeze exactly for this reason in these old cars. Use a Water Wetter product with deionized water so no damage to carpet. Absorbed water from passenger floor from with a towel and no one was the wiser.
To to go home just bypassed heater by removing a hose from car at firewall and from water pump fitting and circled back to water pump fitting the hose removed from heater fitting. Took a full gallon of water to replenish. I had checked cold before leaving home and was full. So must have been a catastrophic failure to lose a gallon in a couple of minutes. Have not torn down yet for post mortem. Appears could be a multitude of different issues from heater valve to core to internal hoses. The fact so much water in just a couple of minutes is interesting. Had zero leaks prior to yesterday. First guess is internal hose failure,,,,particularly as just swapped out windshield last week. I did not do this job, but supposed to be and is a very good guy that did,,,says did not touch heater. By the way purchased windshield assembly from Glassworks the hardtop rebuilder. I will post my thoughts on this later.
My my point is that water leaking into car can find its way to outside on the ground if any bolt holes or other are in floor under carpet.
As as an aside, I spent 45 minutes trying to search for a posting on c1 heaters to no success. I got a lot of completely threads lrelavant on c6’s to transmission problems when entering c1 heaters, etc. What am I doing incorrectly? I finally found this helpful thread with a great pdf by manually searching thru postings.
Last edited by Sxrxrnr; 08-14-2018 at 03:37 PM.
Reason: typos
Wouldn't a single cut-off valve (on the TO core line) accomplish the goal?
Why would you need to block the FROM core line?
The cooling system is under pressure. You NEED two valves, other wise teh pressure differential would blow everything out the un valved line, if it was leaking.
Doug
02-01-2017, 03:53 PM
C1 heater replacement proceedure
