water bypass tube help

Discovered a leak today on the side of my water bypass tube (nipple). The one in my car is the original so I guess after over 50 years things happen. Anyway has anyone ever changed one in the car? Who sells a replacement?

See pic below. Any and all help appreciated.

Mac

Maybe a dumb question - Are you sure it's not just the hose leaking?

71coop said:

Maybe a dumb question - Are you sure it's not just the hose leaking?

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It looks like you can see through it in the picture.

Is this threaded in or is it pressed in? I forget.

I got mine at O'Reilly's. I don't have the part number, nor can I remember exactly what it was called, but I do know that I got it at O'Reilly's. Usually, they are pressed in. Remove the old one, line up the new one, and use a small piece of 2x4 or equivalent to knock it into the hole. I smeared a very thin layer of permatex around the base to insure a leakproof seal.

71coop said:

Maybe a dumb question - Are you sure it's not just the hose leaking?

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Positive. With the hose removed, the nipple continues tonleak.

will e said:

It looks like you can see through it in the picture.

Is this threaded in or is it pressed in? I forget.

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It's pressed in. How do remove the old one?

73MustangCoupe said:

I got mine at O'Reilly's. I don't have the part number, nor can I remember exactly what it was called, but I do know that I got it at O'Reilly's. Usually, they are pressed in. Remove the old one, line up the new one, and use a small piece of 2x4 or equivalent to knock it into the hole. I smeared a very thin layer of permatex around the base to insure a leakproof seal.

Click to expand...

How did you remove the old one?

Ford refers to this press-in tube you need as a water bypass tube. Its original application dates back to '58 when it was used as a bypass tube on the newly released FE engine family. The name just stuck, and Ford never changed it regardless of the engine application over the years.

The Ford part# is C5AZ-8555-A (replaced by "B") and is 5/8" OD x 2 1/2". Depending on your parts source, you may have to cut the tube length down since it is a multi-application part. The Ford version is no longer available, but since just about everyone has a NAPA store, you can try them. Their part # is BK 660-1580.
If you have a favorite part store other than NAPA or an online source, they should be able to cross the Ford or NAPA part number to something in their product line.
Since most of the tubes I had to replace were already rusty and leaking, I used a pair of vice grips or carefully tapped a screwdriver between the block and tube until I collapsed it enough to remove it.

secluff said:

Ford refers to this press-in tube you need as a water bypass tube. Its original application dates back to '58 when it was used as a bypass tube on the newly released FE engine family. The name just stuck, and Ford never changed it regardless of the engine application over the years.

The Ford part# is C5AZ-8555-A (replaced by "B") and is 5/8" OD x 2 1/2". Depending on your parts source, you may have to cut the tube length down since it is a multi-application part. The Ford version is no longer available, but since just about everyone has a NAPA store, you can try them. Their part # is BK 660-1580.
If you have a favorite part store other than NAPA or an online source, they should be able to cross the Ford or NAPA part number to something in their product line.
Since most of the tubes I had to replace were already rusty and leaking, I used a pair of vice grips or carefully tapped a screwdriver between the block and tube until I collapsed it enough to remove it.

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Secluff,

Thank you for the info. One question, after you get the old tube out, do you put any sealant on the new one before you insert back into the block?

Mac said:

Secluff,

Thank you for the info. One question, after you get the old tube out, do you put any sealant on the new one before you insert back into the block?

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Smear a little dab of permatex around the tube end and push it home.

Here's some options that you should be able to get locally...


Amazon, Napa and O'Reilly. Any parts store should be able to cross the part numbers.

I drilled and tapped mine, but it was on the engine stand at the time.

I tapped mine for NPT. Maybe drill the old one over.

PS: maybe not a good idea to drill it over if the engine is in the car and you are not able to clean up the mess

Mac said:

Discovered a leak today on the side of my water bypass tube (nipple). The one in my car is the original so I guess after over 50 years things happen. Anyway has anyone ever changed one in the car? Who sells a replacement?

See pic below. Any and all help appreciated.

Mac

Click to expand...

mine had the same issue, grab some pliers and pull it out, its pressed in. be careful not to drop flakes and pieces of rusted metals inside when pulling it out. mine was so bad it was coming off in pieces and took forever. Once Removed, got some sandpaper and cleaned it up. clean up the grove in-which the fitting seats in. you want this to have zero pieces of debris left over to not cause leaks later on. Added some Permatex to the outer diameter of the new press fitting, a little bit to the groove too, grabbed a rubber mallet until seated the fitting. fairly easy job.

The problem is the fact we have Stainless Steel in direct contact with cast iron, these are very dissimilar metals and causes galvanic corrosion especially with the coolant in the mix. Hence, why its leaking after 52 years. The sealant should help you never have to touch this issue again.

kiko619 said:

mine had the same issue, grab some pliers and pull it out, its pressed in. be careful not to drop flakes and pieces of rusted metals inside when pulling it out. mine was so bad it was coming off in pieces and took forever. Once Removed, got some sandpaper and cleaned it up. clean up the grove in-which the fitting seats in. you want this to have zero pieces of debris left over to not cause leaks later on. Added some Permatex to the outer diameter of the new press fitting, a little bit to the groove too, grabbed a rubber mallet until seated the fitting. fairly easy job.

The problem is the fact we have Stainless Steel in direct contact with cast iron, these are very dissimilar metals and causes galvanic corrosion especially with the coolant in the mix. Hence, why its leaking after 52 years. The sealant should help you never have to touch this issue again.

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Galvanic issues was the reason I decided to go with Evan’s coolant instead of a water based coolant.

Expensive but I am hopeful it will keep stuff like me aluminum radiator galvanic free

That's good the inhibitors in your coolant are going to be your BFF. Only thing you have to worry about is what you said, the cost lol.
FWIW please use the proper radiator hose clamps, e.g. TKO or spring loaded clamps never use the worm gear or even those pretty anodized hose fittings... they still use a worm gear clamp lol

Did manager to remove the rusted tube. Drove a awl between the o.d. of the tube and the engine block. The tube was so rusted that the top half sticking out of the block came off but the bottom half still stuck in the block. Used a small cold chisel to break the tube wall then took needle nose pliers to grab and twist the bottom half to try and pull out. After several tries I got the bottom half free but it fell down inside the motor. Since I had the thermostat out, I was able to see it and used a combination of a magnet and needle nose pliers to pull it out.

Bought an NOS tube (part #C5AZ-8555-A). Before inserting into block, I took my calipers to measure the tube o.d. Spun the tube while in the calipers and discovered it was slightly "out of round". At that point I purchased an aftermarket tube from Alex's parts. It is an extruded tube and perfectly round. Used my bench grinder to grind a lead in chamfer on this tube, then Permatexed the o.d. of the tube and the bore in the block and used a small oak block and tapped the tube in place (approx 1-1/8 to 1-1/4) sticking out of the block. Let every thing set for a day to allow the sealant to setup then installed new hoses/clamps and the proper thermostat (NPD #8575-5BH) and refilled the radiator. Started up, heated up fine with NO LEAKS.

Also don't forget to "Burp" your system before installing the water bypass heater hose.

No fun, don't want to do it again but since the original tube lasted since 1971, chances are by the time this tube needs replaced, it will be someone elses problem.......