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I'm back and need new chambers.


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Hey all

You could say I have been on hiatus from the forum. Between work, moving and then moving again I was stretched for cash, working on the B just wasn't an option. Time is another enemy of mine but things have smoothed out a bit for the past few months. I am doing better and even though its fall I want to get a few things fixed before it gets too cold.

My problem is I think I have a blown diaphragm in the spring side of the drivers side drive axle chamber. It leaks air from the hole on the back of the chamber and from the clamp around the chamber. I can barely move the truck before the knob pops out when it drops below 60 PSI.

I have never done this before and I want to know if there are any gotchas or precautions I should look out for. I also have no idea what size to get either. I am also thinking to buy two new complete chambers as they are very rusty and I think its time for a fresh set. Any particular brands to buy? I see that some say long stroke and some have long rods. Should I replace the slack adjusters as well?

What to do what to do....

Thanks!

-Thad

What America needs is less bull and more Bulldog!

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Welcome back!

not knowing what type brake chambers you have, but, 30-30 chambers are about $40

Much safer to just replace chamber instead of trying to repair can. BIG spring inside

Success is only a stones throw away.................................................................for a Palestinian

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Welcome back!

not knowing what type brake chambers you have, but, 30-30 chambers are about $40

Much safer to just replace chamber instead of trying to repair can. BIG spring inside

Yup. They're cheap enough. Do the whole thing instead of having that spring pop out and taking your head off. If the slack adjusters look like they are in good shape and dont have any slop just take em off, clean em up real good and grease em and you should be ok.

TWO STROKES ARE FOR GARDEN TOOLS

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since it is for your B have they been upgraded yet to spring brakes or are they single chamber? If they are single chamber it would be a great time to up grade ,not much money and fairly simple. Take one of the old ones off and bring it with you as with seeing it is had to determine if long or short stroke. I posted a thread on how to upgrade took longer to pull the bolts loose than reinstall. You will have to cut the rod so make sure that when you cut it is in the proper position meaning the brake chamber is gaged that means that there is bolt compressing the spring and that pushes the rod out as far as it can go. Make sure to get new clevis/yokes and pins not worth trying to save the old ones.

Slack adjusters can be greased and as long as the locking mechanism still works they should be ok or they are not stripped. You should not have to mess with any adjustments on them if the brakes were working before the air leak. If you have the original style adjusters and the ball socket does not click you may want to replace them, again take one with you when you go to the parts store.

http://www.bigmacktrucks.com/index.php?/topic/24092-b61t-upgrade-to-springbrakes/

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Robert

"I reject your reality and substitute my own."

 

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Thanks guys.

The truck was upgraded to newer style chambers so it shouldn't be an issue to swap them. There is a truck parts place close to home and work so I will pull a chamber and bring it along with me.

-Thad

What America needs is less bull and more Bulldog!

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Okay, dumb question ahead.

How do I remove the cans when the spring brakes are applied? I know there is a way to manually back them off but I don't see a bolt head, only a hole in the middle of the can. Do I have to insert a bolt and if so what size and thread pitch?

The only cheating way I can think of is to chock the wheels and release the parking brakes. Then again with a blown diaphragm I might have to get creative and jerry rig an airline from a compressor or cap off the line to the leaky chamber to build pressure.

-Thad

What America needs is less bull and more Bulldog!

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The ones I am use to take the bolt with the two nubs sticking out the side and you just put it in there and give it a quarter turn then run the nut down with a wrench. Chock the tires and release the brakes and you won't have to give it but a couple turns to hold the spring back. I was going to post a picture of one but was not able to find one.

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Shine a light into the hole, if spring is NOT broke and it looks good to the cage bolt slots, then remove cage bolt from the side of brake chamber, Put nut and washer back on very end of cage bolt, insert and FEEL the two pongs go into the cage bolt slots and take a pair of vise grips and turn bolt 1/4 turn to right. This should lock the cage bolt into the slot, tighten nut all the way in (It will be tight) this should release the spring brake, Remove the clevis pin, airlines and mounting nuts . IF the spring is broken and all jam up so you can't get the cage bolt into slot, the safe way to remove the chamber (If spring is broken, there will not be as much pressure on spring) Is to leave the clevis pin in and airlines on and remove the mounting nuts making sure you are out of the way from the chamber, because it will jump back and it can nail you if in the way. After it comes loose then remove airlines and clevis pin. The park spring is at 500 pound tension, DO NOT REMOVE the bands from around the chamber. Both ways you do not need to put air to system. If your new chambers are not pre-caged, either cage or replace airlines and mount your clevis pin, back off the slack adjuster, and apply air pressure and brake chamber will suck in and make mounting easier.

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Seems to be a lot of advice here so, here is my two cents

1. Chock the wheels front and back (you don't need to disconnect the battery's as there is nothing electrical about this repair and you may need the engine running to build air if the truck does not hold it)

2. Locate two caging bolts, they look like this

post-10018-0-70061100-1384264014.png

3. insert into the hole on top of the brake chamber and key the bolt into the internal lock, (don't use vice grips as it will damage the ACME threads on the bolt) the bolt will only have about 1 1/2 inches sticking out (make sure the nut is near the top of the bolt with a washer) once inserted and keyed use a 3/4" wrench to tighten until the spring is compressed.

(a cheat would be to use the truck air and release the brakes, so you don't have to compress the spring so much, this may work on the good chamber but may not work on the bad one depending on how bad it is leaking)

post-10018-0-70903500-1384265501.png

4. Drain all air from the system mark your air lines and remove them from the brake chamber. The new chambers will be marked for the lines

5. Remove the cotter pin and remove clevis pin from the slack adjuster, (You do not have to mess with the slack adjuster at this time.)

6. Remove the mounting bolts and take the chamber off the truck.

7. Take the chamber to the parts store and get new ones (keep the old ones until you have the new ones mounted, you will have to cage the new brake chambers to cut the rod to proper length, remember to thread a nut on the rod before cutting to dress the threads after cutting or you may have difficulty threading on the clevis/yolk)

8. Reinstall in reverse order, charge the brakes remove caging bolts and store on side of chamber or in the truck. (depending on how accurate your cuts are you may need to readjust the brakes) Should take about 20 minutes per side to install and replace.

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Robert

"I reject your reality and substitute my own."

 

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Just be aware you are handling a 'bomb'.... do NOT get curious and try to dismantle the maxi, I really don't want to post our safety departments graphic photos of what the spring will do to your skull...

may I politely suggest that this is one aspect of hobby truck repair that should be supervised by a qualified professional if it is your first time repairing air brake parts, this item needs a correct set-up, cutting the pushrod to match the removed one could be an error if the old one was wrongly cut.

the angle of the rod to slack adjuster needs to be correct to assure leverage is correct and matched side to side, also a perfect time to inspect other related parts.

some good information given here but I personally don't give out instructions on repairs on the internet, be careful applying info you read as it is caveat emptor, not wanting to be an a$$hole but after 40 plus years of doing this I have seen too many obituaries and accident reports.

have you looked at the Bendix website?

just be careful... if you can find someone to show you through it all the better.

now back to your regular programming........ :twothumbsup:

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I agree with BC mack. the pushrod length needs to be right. it would be easier if you were takin off old service brakes and putting on maxi cans, you would just put the clevis on past where you need it and measure the old rod, and cut the new one to length. needs to be cut with the bolt in it if I remember or you can do what I do and screw a air nipple in them with a shut off, air them up til it releases and cut the rod to length and bleed the air off slow. you can buy just the piggy back portion of the chamber but its a pain in the ass and I think the last two I bought about a year ago for the whole chamber was $40 a piece and they were made in the usa, the china ones are cheaper.

post-6-0-64947600-1408238925_thumb.jpg

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If you can't cage the maxi, Build up your air, have someone release the brakes and back off the slack adjuster. Just don't mess with the bands that hold the cans together. If they are real rusty (like everything in NY) be careful handling them after removal as they could come apart on their own if you drop them.

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Mike

Thanks for your reply, I always try to contribute the best answers so folks can read it and make a decision if it is something they can do or best left to the "experts"

I recently started teaching again part time at the college level a couple nights a week and recently talked about a similar topic. Most systems are basically the same, it is the manufactures nuances that need to be considered. Everything has an inherent danger and it is up to each person to determine the level of risk they want to assume. I have seen more battery accidents yet most would not think twice about changing them.

Robert

"I reject your reality and substitute my own."

 

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Mike

Thanks for your reply, I always try to contribute the best answers so folks can read it and make a decision if it is something they can do or best left to the "experts"

I recently started teaching again part time at the college level a couple nights a week and recently talked about a similar topic. Most systems are basically the same, it is the manufactures nuances that need to be considered. Everything has an inherent danger and it is up to each person to determine the level of risk they want to assume. I have seen more battery accidents yet most would not think twice about changing them.

Keep up the good work Thomas. Sure wish I could be a student, but too far away for me. You have any of those eastcoastdiesels in your class?As for safety.....ya can't be too safe. When you think your great at something, then you've messed up.

mike

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