Leaking spring brake chamber

[3poffroad]

After taking my M925 out this past weekend I noticed it was VERY slow to build air, and wouldn't build past 65PSI at idle. Upon inspection today I noticed one of the rear spring brake chambers leaking out air between the cap and the clamp. Now I know servicing these is not safe nor easy.

Would it be easier to take the assembly off and get it rebuilt, who can rebuild them? Or who sells the whole spring/service pod that I could buy and just put on there?

 

[simp5782]

Try truck pro or a big truck repair facility. There is a Truckpro in houston

You can get them from Memphis equipment and Oshkosh. Just take the numbers to truckpro and see what they can come up with. I have ran the NSN's thru my system on front and rears and nothing comes up for the whole assembly thru local parts houses.

 

[VPed]

While I agree that there is a significant element of danger, I do not agree that it is not easy. The replacement diaphragms I got were in stock at NAPA with part numbers MBI-DP12 and MBI-DP16 (size 12 and 16 diaphragms, may as well do both on the stack while you are there). Someone on here suggested buying a new cage bolt at the same time for added assurance to things going ballistic. Taking your time, especially with the first one and treating the compressed spring like a loaded gun is a requirement. I never even disconnected the air lines when I did mine. It took me about one hour to change out both diaphragms on the first set I did.

Taking the truck to a big truck place to have the diaphragms changed out may be another option because I think a ready to install dual chamber assembly may be a little hard to come by unless ordered from a military surplus site.

 

[M35A2-AZ]

While I agree that there is a significant element of danger, I do not agree that it is not easy. The replacement diaphragms I got were in stock at NAPA with part numbers MBI-DP12 and MBI-DP16 (size 12 and 16 diaphragms, may as well do both on the stack while you are there). Someone on here suggested buying a new cage bolt at the same time for added assurance to things going ballistic. Taking your time, especially with the first one and treating the compressed spring like a loaded gun is a requirement. I never even disconnected the air lines when I did mine. It took me about one hour to change out both diaphragms on the first set I did.

Taking the truck to a big truck place to have the diaphragms changed out may be another option because I think a ready to install dual chamber assembly may be a little hard to come by unless ordered from a military surplus site.

It is not that hard, you just have to be safe about it. I get my diaphragms from Napa also.
Service side is a T12 and spring brake side is a T16.

 

[98G]

Find someone that's done it to walk you through the first one. Use copious amounts of caution...

 

[74M35A2]

I think as long as you read the instructions carefully, and then loosen the clamp while containing the can in the jaws of a large vice for extra safety measure, it would be fine. They say they contain enough spring pressure to physically kill you. I think as others have said, NAPA sells the diaphragms, and complete cans. Price differential is up to you decision based upon level of confidence.

 

[m16ty]

If you do it yourself, just make for sure you have the caging bolt in place and tightened all the way up before unbolting anything. Even after that is done, never stand directly in front or behind it when taking it apart or putting it back together.

As said above, probably be best to have somebody experienced walk you through it the first time. It's really simple to do as long as you follow the precautions. Replacing the diaphragms is a fraction of the cost of a new can also.

 

[randygk]

Good advice So Far

Caution and knowledge the key words to use in avoiding the 100 lbs of spring in a 5 lb can

 

[74M35A2]

Looks like the coily spring monster that jumps around on the Q-Bert screen.

 

[Floridianson]

Yup good key or new, Most of the keys we use are 3/4 head key. Also oil the threads of the key shaft. 1/4 turn to lock and run the nut down close to tight but don't crank it as if it was a wheel stud. If you want to be safe you could wait while you got a cig or a cold drink. If it holds that long it should hold for the repair. Just watch where you put it while you do the rest of the repair. I had a thread somewhere on the good cleaning of lips and such. As said by others the pancake will be taller and put in upside down from what you take out but it will work. In my thread it shows how to get the rubber well seated in the lip using your finger nail. Got to get it in right and seated but it is not a problem to do it.http://www.steelsoldiers.com/showth...er-diaphragm-problems&highlight=brake+chamber

Found it.

 

[73m819]

Yup good key or new, Most of the keys we use are 3/4 head key. Also oil the threads of the key shaft. 1/4 turn to lock and run the nut down close to tight but don't crank it as if it was a wheel stud. If you want to be safe you could wait while you got a cig or a cold drink. If it holds that long it should hold for the repair. Just watch where you put it while you do the rest of the repair. I had a thread somewhere on the good cleaning of lips and such. As said by others the pancake will be taller and put in upside down from what you take out but it will work. In my thread it shows how to get the rubber well seated in the lip using your finger nail. Got to get it in right and seated but it is not a problem to do it.http://www.steelsoldiers.com/showth...er-diaphragm-problems&highlight=brake+chamber

Found it.

To be SURE the caging bolt will hold, BEFORE you loosen the band, give the end of the tightened cage bolt a good hit with a 2/3 lb hammer, other then scarring the crap out of you if the bolt lets go, nothing will happen, better to have it let go now then the once the band is removed and the pot gets bumped.

 

[mdainsd]

Caution and knowledge the key words to use in avoiding the 100 lbs of spring in a 5 lb canView attachment 623774

YIKES! I am sure glad I got mine all swapped out last weekend BEFORE I found this thread and saw THAT picture.

 

[74M35A2]