Maglite with damage from battery leakage; repair possible?

11-6-09 UPDATE:

I completely disassembled the light and used the acid wash that Sarge suggested to neutralize the etching due to the battery leakage. I then used stiff nylon bristle brushes to scrub out the excess crud, followed by a thorough wash with hot, soapy water. Althought the inside of the barrel looks pretty rough in a couple large areas near the tailcap end, the switch assembly is untouched and the tailcap is in better condition than I thought--the threads are completely intact, and the only corrosion on the cap is a small area where the battery spring seats. The O-ring seat on both the tailcap and barrel are fine, and the tailcap threads on the barrel are in good enough shape that thread engagement isn't an issue. She should have a few good years left in her.

One thing I did note when I had it apart was that the tube size is quite different from a newer model 2D we have (the newer model as the "D" prefix on the serial number). The heads nor tailcaps are interchangeable. I measured both lights with a caliper and got these numbers:

Old model: barrel OD 1.640", wall thickness .134", head ID 1.645"
New model: barrel OD 1.550", wall thickness .105", head ID 1.555"

Holding the two lights side-by-side you can easily see the tenth of an inch difference in diameter. Interestingly, the outside dimensions of the heads, both diameter and length, are the same.

Original post:

I have a 4D Maglite that I've owned for more than 25 years now (got it for my 16th bday). My dad purchased it from Wald's Police Supply in Dallas, and it bears the Wald's stamp in the barrel. That light accompanied me on many a campout and road in every car I've owned through the years. Needless to say, it has sentimental value.

These days I get much more use from LED lights, but the trusty Mag still rides in the car. Pulled her out the other day for some reason and got no joy when I clicked the switch. Thought the bulb might be shot, so I pulled the tailcap to replace the bulb. That's when I discovered that two of the batteries leaked and etched the inside of the barrel. Unfortunately, the leakage got into the threaded area at the tail and ate some of the threads on the tailcap. Thankfully, the etching didn't make it to the O-ring seat, so it still maintains its water resistance.

I can still screw the tailcap into place, but it's a gritty travel. So, my question is do I have any recourse to address the damage done by the battery leakage? Is the answer to live with it? Will it get any worse over time on its own? I'd like to keep the light and keep using it rather than retire it as a wall hanger, but I'm just not sure what my best course of action is. I appreciate any advice you all can give.

Regards,
Scott

I've had batterys leak in one of my mag lights and it can make a mess. I took every thing out of the main tube, washed it with hot soapy water and a brush. While you have it apart you may want to clean and treat the switch with deoxit. Don't leave alkaline batterys in a light for more than a year or when they start to get weak.
Billy

Hit the corrosion site with some lemon juice to start with and stop what it's doing. Be liberal with it. Later you can rise it with water.

Your tube will survive (I understand keeping it for sentimental value) but I think I'd get another tailcap.

Clean up the tube with a cylinder hone to smooth out any corrosion inside it. Run a dremel nylon wheel on low speed through threads to smooth out any rough spots. Replace tailcap, spring and o-ring.

Sleeve the cylinder with PVC and run 5 C cells. Not guaranteed to prevent leakage but should it happen the cells won't seize to the tube.

TKC said:

Write the battery company. Many have policies that if their batteries do damage, that they will pay to replace the device.

Click to expand...

He said we wanted to fix it, not replace it.

Someone correct me if I'm wrong, here, but, isn't that 25 year old MagLite the older, larger diameter style as compared to the current crop of MagLites? If so are there tailcaps even available for them? I know that the tailcap on my old MagLite does not fit the newer ones and vice-versa.

Thank you all for the responses. I do want to keep the light as is, so I'll implement the fixes you all suggest to keep her running.

Interesting point about the tailcap. We have other D-cell Maglites at the house that are newer models, so I will see if the tailcaps are interchangeable.

Again, my thanks for the info!

I have two older larger tube Mags. One 2D I have had since 85 or so and a 4D. They have aftermarket D-ring tailcaps but the originals are long missing.

The 2D has had a battery failure twice. I did the acid wash, wire brushed the threads to clean them up and then spritzed the interior with Krylon clear paint to seal them. Don't know if that last bit was needed but it felt to me like it couldn't hurt.

The 2D now has a PVC tube inserted and is running a 3 cell LED lamp off of three C cells. I removed the anodizing from the inside tailcap and used a different cut down spring that just flops around in the cap. Normal mod there. I have also replaced the switch assembly once. The battery post fell off. There are still some sources of the switches for the older models.

It is the oldest good light I have had continuous ownership of since purchasing it.

Here is the old boy and his little overworked cousin....


They reside in a shelf of honor. The 2D still gets used around the house. I now have newer general purpose lights to scuff up and abuse. (QIII, for one)

A source list for parts suppliers.

Flashlight King has old style D tail caps.

Pellidon said:

A source list for parts suppliers.

Flashlight King has old style D tail caps.

Click to expand...

Plus Flashlight King has some of the best parts pricing and very good shipping.

Bump for the update in first post.

A: Flashlight King is my first parts stop. Usually the only stop. :thumbsup:

B: The old non D serial lights have bigger tubes and any parts in direct contact with the tube. They accommodated the older paper wrapped batteries of the day, usually zinc carbon cells. My venerable 2D and it's big 4D brother are relics of that age. Both purchased before 1985.

FLK and many of the sources have old model parts.

And in an OT note, Mag informed me that in the next few months (12+) they will have the new MagLed module and reflector available as replacements for New model Krypton bodies. Won't fit the older bodies however.