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Brake Band Not Round

Posted: Fri Jul 16, 2021 12:00 pm
by NAM VET
Not that I should expect, or even hope my replacement brake band would snug up nice and round when fitted to my Transfer Cases's drum. I spent all morning, hot and humid, dripping with sweat, trying to install a new band with the proper clearance all around. Per the TM, adjust point A, then B, then C to have .015 clearance all around. Except there is a high spot on the lower band. No matter how I adjusted and mis-adjusted the J bolt and the adjustment screw, I finally had to accept that having sufficient clearance most of the circumference left me with about a third off the lower part just not going to effectively wrap onto the drum. I tried to think thru the geometry of the three adjustment points, and how each would affect the circumstance of the other parts. I barely passed 8th Grade Geometry, and only that because the elderly math teacher took pity on me.

Then back to adjust the front clevis/pin on the hand brake lever, and finally got the brake to release , and then stop my rolling truck when pulled back 3 or 4 clicks.

No telling how many times this steel band has been heat warped and relined, so I am just trying to tell myself that I am darn lucky to even be able to source a replacement band. I will test it by just driving my truck a bit, then put my infra-red heat sensor gun on the drum and see if it is showing too much heat from dragging, and need a further fine tune of Point A, B, and C.

I have several oil soaked bands, and may play with them to see if by chance one might be less heat warped, and have it re-lined. My eyes are watering from the bits of grease that fell around my glasses when looking up. Only had to wrap one bandage around a lacerated finger this time.

Hal

Re: Brake Band Not Round

Posted: Fri Jul 16, 2021 2:03 pm
by m-37Bruce
Great work Hal,
I did mine so long ago, I forgot how much work it was. I do remember the weather was not like what we are dealing with.

Re: Brake Band Not Round

Posted: Tue Jul 20, 2021 4:52 am
by sturmtyger380
Interesting... I had that on my list of things to do when I started working on my truck a few years ago. I bought the replacement band. Flat as a ruler. Then later at a show I picked up an NOS band assembly. All mounted and ready to slide over the drum. Maybe that was a good move.

Re: Brake Band Not Round

Posted: Tue Jul 20, 2021 1:55 pm
by m-37Bruce
sturmtyger380 wrote:Interesting... I had that on my list of things to do when I started working on my truck a few years ago. I bought the replacement band. Flat as a ruler. Then later at a show I picked up an NOS band assembly. All mounted and ready to slide over the drum. Maybe that was a good move.
That was an excellent move!

Re: Brake Band Not Round

Posted: Wed Jul 21, 2021 8:12 am
by NAM VET
after spending some hours the other day under my truck, attempting to fit my newly relined brake band to the drum, and adjusting the in-cab hand brake lever to give me more "pull" to engage the band, I went out to check things. I drove in my driveway back and forth, and would yank on the hand brake to stop my truck, which it did just fine.

So crawled back under to see how the clearances were per the TM, and again found a "high spot" at about 4 o'clock on the band, making it necessary to have excessive band clearance on the brake drum at about 3 to 6 o'clock. I have a snug .015 clearance around the top to point A, or the 9 o'clock bolt position, but decided to just accept the two inches of the high spot, and let that wear in.

I wish I had a full circle of my band gripping the drum, but I just can't get that. The drum is 8.5 inches in diameter, and I may order another re-lined one, and clamp it to that diameter on my work bench, and see how round another band is.

But at least it brakes satisfactorily now, and besides, I carry two wheel chocks for any parking on a slope. Plus of course, leaving my trans in a low gear. Here is a pic of wha ti ended up with. Hal
[url=https://postimg.cc/dZwk0pWC][img]h ... .jpg[/img][/url]

Re: Brake Band Not Round

Posted: Wed Jul 21, 2021 8:20 am
by NAM VET
well, I was just looking back at some pics of my transfer case when I installed it a couple of months ago, and noted that in this pic, my band is just fine. So when I get the energy, I will go back underneath and see why I can't get it round like it apparently was then. I will get this sorted out. Hal
[url=https://postimg.cc/nC15MmL9][img]h ... .jpg[/img][/url]

Re: Brake Band Not Round

Posted: Wed Jul 21, 2021 11:17 am
by NAM VET
So I just took the band off, and used a drum sanding wheel on about three inches of circumference of the band, reinstalled it, set the clearance, and is better. Hardest part is spreading the three cotton keys properly. The small area where its is snug will just have to wear in. I am done with this. Hal

Re: Brake Band Not Round

Posted: Wed Jul 21, 2021 12:42 pm
by John Mc
The image in your 11:12 AM post is not displaying. I believe this is because the "URL" flag is in there twice. Try taking out the leading (url) before the picture and the trailing (/url) and see if it works then. (In your post, they are in square brackets. I had to use parentheses here so the system would not think I was trying to post a picture.

Re: Brake Band Not Round

Posted: Wed Jul 21, 2021 2:19 pm
by NAM VET
John, the pic shows up fine for me, but I have already deleted it from my camera and computer, so can't re-post what it looked like. Better now. Hal