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Is there any chance to repair an original Harrison tank?
I pulled the lower hoses off to try to diagnose a leak and noticed the ends of the pipes were pretty corroded and deformed.
I'd like to see if i can first trim back the ragged edges and reform the round ends, but not sure if there'd be enough tube remaining to clamp to.
Otherwise, are there shops that can weld new tubes in aluminum?
I'd really like to preserve the original tank if at all possible.
Hi Bb,
While I can understand your desire to retain your original tank, I think the repair will be difficult and costly….even after finding some with the skill and equipment to do it
.
I'd think the likely source for tubes would be another tank that has good tubes that can be transplanted by the person who does the repair.
You might be able to slide the hoses further up on the tubes but you still chance crushing the pipes at that point when you tighten the clamps.
Also the tank itself may have deteriorated too much for the repair to be made.
Perhaps you could begin to look at e-bay for a used original with a date that works for your car that's in better condition.
I'd think you could by a used tank for less money than the repair of your tank would be.
Good Luck!
Regards,
Alan
Thanks Alan,
Well I'm giving it a go.
Bought some new hoses (3 of the 4 that come out of the tank - just not the overflow drain hose).
Did my best to remove the "shards" of mangled Al from the 2 lower tube ends.
And then formed them back to round as best I could.
Fed the new hoses over the tubes as far as they would go, and then gingerly clamped new hose clamps up as high on the tubes as possible.
So far, after getting it up to temp at idle in the garage, no leaks!
I'll take it out for a ride shortly, but this car doesn't seem to run hot ever (new radiator from prior owner).
One concern I have, was that the old hose going from the tank to the heater core was a 3/4" ID but was a much thicker wall than what was on the front line (from the tank to the water pump). Not sure if a much stronger hose is required for that rear line, but for now, I used the same thinner walled 3/4' hose on both.
Any reason to think I need a stronger hose for the tank-to-core line?
Hi Bb,
I'd think both hoses would have the thicker wall.
I think you need to be watchful because the missing ribs were there to help the clamp hold the hose in place in case of an overheating/over pressure situation.
You may be fine. But I'd be nervous enough about a hose slipping off that I'd spring for another tank.
Regards,
Alan
Yes ..these tubes can be formed and the bubble ends can be put into them and they can be welded back onto your expansion tank...BUT...it might cost more than buying a new one.
Thanks Alan and Dub.
My thought is that the condition of those 2 tube ends was already pretty degraded, and no rib or bubble end existed for X number of years.
How high does the pressure get at those fittings? Isn't there a over-pressure protection in the tank cap already?
And what about the hoses themselves? The 2 lowers were both 3/4" ID, but the rear line to the heater core was a larger OD, so it had a thicker wall.
The standard replacement coil of 3/4" ID hose I bought did match the front line (to the water pump), and they both fit well.
Can anyone provide the original specs of those hoses, and know whether a thicker hose is required for the rear line (or both)?
Thanks!
Hi Bb,
The pressure in the overflow tank is the same as in the radiator because the coolant in the tank is below the pressure regulater cap for the cooling system…. 15#.
There are definitely 2 size heater hoses hoses running from the engine to the heater core. 3/4" and 5/8".
The larger 3/4" hose runs from the water pump to the overflow tank and from the overflow tank to the upper pipe on the heater core.
The smaller 5/8" hose runs directly from the intake manifold to the lower pipe on the heater core.
Regards,
Alan
Thanks Again Alan,
My main concern is the 2 different hose types I removed from the tank lower fittings.
The front hose (to the water pump) was 3/4" ID and a standard OD. The rear hose (to the heater core) was also 3/4" ID but a larger OD, with a noticeably thicker wall section.
Any reason to think that there would be higher pressure in the rear line than in the front? I doubt it, since they both tap into the same tank pressure, but not 100% sure.
As long as the hoses hold at the clamps to those mangled tank tubes, should I be OK with the "normal" 3/4" heater hoses at both the front and rear lines coming out of the tank lower fittings?
Also - at what point do I "give up the ghost" and spring for a new reproduction overflow tank? (if I can't get these connections to hold pressure). A new repro tank with a correct date stamp will run almost $200! And the originals available are running close to that, but look somewhat close in condition to the one I've got.
Is this one of those typically "expendable" parts that are not worth keeping on life support?
Last edited by Bergerboy; Jun 19, 2017 at 10:16 AM.
Hi Bb,
Typically the exact same hose would be used from the engine to the tank and from the tank to the heater core.
Since yours seem to be different I'd think that indicates either of the 2 pieces was replaced at some time, but not the both.
I figure the tank is an expendable item to some degree because of it's somewhat fragile construction. I don't think the designer ever thought we'd still be trying to use them 45+ years later.
One reason to spring for a new tank is that should you try to use your old tank and it fails the mess anti-freeze makes when sprayed around the engine compartment isn't something to look forward to.
I think another tank is in the not too distant future for you even if you do get a temporary fix on this one.
Regards,
Alan
I would not run the car without those tubes being correct. Taking the chance that these hoses come off is not worth it...but remember I service Corvettes so I have to worry about a warranty/ guarantee.
Either get it repaired if you have access to friends who can help you in this that can keep the cost down.... or.... get a new one.
Alan is correct on why you have two different wall thicknesses of hose. Someone changed them out with what they had.
New replacement tubes are available for the tank.
Not sure if I am allowed to name the company.
It starts with your cars name and ends with the continent it was made on.
If you are concerned about originality those tubes were gas welded not tig welded.
Not a lot of people left who can gas weld aluminum.
Also - at what point do I "give up the ghost" and spring for a new reproduction overflow tank? Is this one of those typically "expendable" parts that are not worth keeping on life support?
For one thing, you need to quit calling it an overflow tank. It is an expansion tank under pressure and would be the top part of the radiator if space permitted. Get a new repro and enjoy driving your car. If the radiator is suspect, get a new aluminum one of those also. This idea of restoring every original part may be justifiable for an ultra rare, high value car. For most others, it is only a dream that somebody in the future will appreciate all the money you spent and compensate you for your effort.
After 13 years I have finally decided to get new leather seat covers (as opposed to having the original comfort weave covers repaired at a much higher cost) and carpet set for my very original side exhaust L36 coupe. Quite frankly, I am tired of the holes and tears and yellow dust all over the interior, as well as the smell. I want to enjoy driving the car. I plan on giving all the worn out original stuff to the next caretaker in boxes.
Last edited by Faster Rat; Jun 20, 2017 at 12:35 PM.
Overflow Tank Repair?
