M939 Series Air Brake Cage Bolts

[Andy1234]

I've read a handful of posts where folks were asking about the cage bolts and what they looked like.

I found one in my truck the other day, so here's a few pics for those who are interested.

The nut on the end is 3/4".

Andy

 

[m16ty]

There should be one in the holder in each (spring) brake chamber. If they are missing you may want to get some. You never know when you may need to cage your brakes.

 

[Andy1234]

I have plenty, this is an extra.

Pics are for info and reference only..
Andy

 

[m16ty]

I have plenty, this is an extra.

Pics are for info and reference only..
Andy

I figured you did. My previous post was for the other readers.

 

[dezert ratt]

i dont have a truck with air only brakes, and ive heard the term caging the brakes alot. what does it actually do? im guessing it releases the brakes? i know i should probably search it but i was just lookin for a quick answer to cure my curiosity. thanks

 

[wreckerman893]

i dont have a truck with air only brakes, and ive heard the term caging the brakes alot. what does it actually do? im guessing it releases the brakes? i know i should probably search it but i was just lookin for a quick answer to cure my curiosity. thanks

It does in fact release the brakes so that the vehicle can be moved, towed or pushed/pulled onto a trailer if it won't build air.

If you cage the brakes you will have no stopping power.....if there is any incline at all you should have the vehicle chained or cabled to another vehicle or solid anchor to prevent it from getting away from you.

 

[rumplecat]

Looks like I should replace mine, yours are a lot prettier than mine! My middle axle has parking brakes by Anchorlok, and I am short the two bolts for them, so off to the truck parts store for me, I hope they aren't some odd ball arrangement!

 

[swbradley1]

There should be one in the holder in each (spring) brake chamber. If they are missing you may want to get some. You never know when you may need to cage your brakes.

Depending on how well your truck was serviced caging them may or may not help either, as evidenced by our wonderful recovery of Sandflea's (Westech) 915. No amount of caging worked.

 

[73m819]

If you do not know the safe way to cage and and what to check for, HAVE SOMEONE SHOW YOU

 

[m16ty]

I have seen bad things happen if the caged brake has brake air pressure applied (somebody pushes the brake pedal with air in the tanks with the bolts in). It can break the bolts and/or chamber and parts can go flying.

 

[Craig A Tull]

When you cage the brake chambers all you are doing is removing the park/fail safe operation of the chamber, if you have operating pressure for the system and the the system is otherwise working you would still have "service" brakes, the first picture shows the brakes in the "parking" off and "service" off (this would be as there was no air pressure in the system and the caging bolts are installed), the second shows it "parking" off and "service" applied third shows it in "park" or "fail" mode. hope this helps, Oh yes I almost forgot, I had a rusty chamber explode on me while installing a caging bolt, no air in the system, SO ALWAYS be careful not to position yourself directly behind the chamber and as stated above be aware that when you cage the brakes they will (or should) release and you can have a runaway truck/trailer on your hands.

 

[quickfarms]

When caging a truck that gas sat the brake shoes can rust to the drum and you may need to tap the drum with a hammer.

I have found some caging bolts that use a 13/16" nut.

We do not use the caging bolts that are on the brake cans because the tend to be rusty and just a pain in the but. Always carry spares but the tow truck should have a bunch on it when they pick you up.

 

[73m819]

When you cage the brake chambers all you are doing is removing the park/fail safe operation of the chamber, if you have operating pressure for the system and the the system is otherwise working you would still have "service" brakes, the first picture shows the brakes in the "parking" off and "service" off (this would be as there was no air pressure in the system and the caging bolts are installed), the second shows it "parking" off and "service" applied third shows it in "park" or "fail" mode. hope this helps, Oh yes I almost forgot, I had a rusty chamber explode on me while installing a caging bolt, no air in the system, SO ALWAYS be careful not to position yourself directly behind the chamber and as stated above be aware that when you cage the brakes they will (or should) release and you can have a runaway truck/trailer on your hands.

The above is not always true, it depends on the type of system (where the spring brake is), some only release the spring brake, others will cause no brakes on the caged wheel

 

[m16ty]

The above is not always true, it depends on the type of system (where the spring brake is), some only release the spring brake, others will cause no brakes on the caged wheel

I've seen several chambers that when caged the service brakes won't work. You should still have front brakes though as I've never seen spring brakes on the front.

 

[Csm Davis]

Okay he specified the 939 so here's my two bits if the emergency brake is properly adjusted the manual part will still hold also the front brakes I know still function and 90% that the rears will also just without a spring safety.