Brake Springs

dr deuce · Post by **dr deuce** » Mon May 23, 2005 6:43 pm

The brake springs on the CCKW rears and Banjo fronts are a weird spring. You can buy them from Jim Carter Chevrolet for about $8 each.
They are a cheap investment in your truck. These springs break! If one breaks when you are driving someplace, you will be going no further as the shoes will move out and apply the brakes lightly which will overheat the drum etc. If the spring fails while the truck is sitting for a long period of time, it may allow the shoes to contact the drum and rust to it. In addition, if there is a ridge on the inside of the drum from wear, you may have a devil of a time to get the drum off as the shoes will not want to allow the shoes to pass over this ridge.

There are a couple of failure modes: One that happens on the front is that the spring rides close to the metal spider that holds the shoes and guides for the shoes. I have seen water wicked up from the bracket to the spring and rusting and weakening one side of it. A second failure mode is that the spring rubs this spider as the shoes wear. A third mode which I just saw today on a Chevy (both front sides!) was that the last loop on the spring, the loop that keeps the end that swivels and attaches to the shoes, broke off allowing the end piece to pull out.

The first time I rebuild a Banjo front, I grind about 1/8" off of the spider area just below the spring to provide additional clearance for the spring.
I always use new spring on a rebuild and inspect the spring carefully when doing any brake work.

If you see a spring that is starting to curl up, or is very rusty, replace it! I always carry a spare spring and a brake spring tool with me.

Steve AKA Dr Deuce

joel gopan · Post by **joel gopan** » Mon May 23, 2005 10:54 pm

This is possible with trucks that have had years of private civilian use, and allowed to sit, but may not be a big issue with trucks returned from European Countries that have given the units good preventive maintenance, especially Norway. The best favor an owner can do for his/her truck is to service the wheel bearings and replace and lube all brake components so that they operate as were intended. it makes for happy driving, and you will not have to spend all your spare time monkeying with a sick truck. A week or two under the truck to put the brakes into spec, will give you years of trouble free operation. The parts will not be out there forever to do this.
Joel

armydriver · Post by **armydriver** » Tue May 24, 2005 9:35 am

Thanks to the Doc and Joel for this great advice. We too often forget about the brakes until they fail, then we think about them instantly. Good information from both of you guys. This is what this site is all about.

dr deuce · Post by **dr deuce** » Tue May 24, 2005 11:16 am

Actually, unless the truck is kept in a controlled climate, the brake springs will eventually be a problem. They rust due to condensation from changing temperature conditions and possibly rubbing on the spider in front.

In the 80's I replaced all the wheel cylinders and brake springs on my cargo CCKW. I recently had a rear cylinder leaking a bit and pulled the wheel/hub to replace it. The spring (new in the 80's) was just beginning to get the 'death curl' so I replaced it.

Interestingly, I always have a complete set (6 minimum) of return springs hung into one of parts racks. The latest ones are from Jim Carter (no I don't get anything from an endorsement...) and arrived unpainted. They have been on the rack for over 2 years now and there is not a sign of rust and I cannot perceive any oil on them.

Besides at least one spring, I keep a spring tool in the truck too. Some of the spring tools work and some do not, so if you buy one, make sure it works!

Steve AKA Dr Deuce