ThaddeusW Posted November 23, 2013 Author Share Posted November 23, 2013 Okay,So I got the chambers off this weekend.Yesterday I devoted about 4 hours to getting just the bad chamber off. At first I tried to be gentile and came to realize that everything is rusted up and frozen pretty good. The bad spring chamber I took off by applying air from a big compressor directly to the quick release valves for the spring brakes. I then removed the spring can from the service half thinking everything would be easy after that. I was wrong. The cotter pins on the clevis to the slack adjusters were frozen, even a punch wouldn't drive them out. I tried filing them down until the ends were flush with the pin and drive the pin out but again, the pin was frozen tight. I then said screw it, im going to replace everything. And cut the clevis with a angle grinder. Thankfully the bolts holding the slack adjusters were coated with anti-seize, they came right off with no problems and just a wrench.Today I took the second chamber off and again I had to cut the clevis but I learned from yesterday and got the chamber off in under 30 minutes. Big difference in time. I will use this chamber to measure the stroke. I have come to learn long stroke means 3 inches of stroke and regular means 2.5 inches, only a 0.5" difference not that much longer. At work I can better rig up air lines to release the spring and apply the service brakes to take a good measurement.I want to switch to auto slack adjusters, anyone have any input on that? I figure that while I am at the rear brakes I should be smart and replace as much as I can seeing how this truck had sat for 7-9 years. No sense in taking chances with the most important part of the truck, brakes. And anyone have any recommendations, Bendix, Gunite, etc? Quote -Thad What America needs is less bull and more Bulldog! Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218126 Share on other sites More sharing options...
Joe Ditchkus Posted November 23, 2013 Share Posted November 23, 2013 I like the manual adjustment slacks. Not much work to keep adjusted in a hobby truck. We run auto slacks in our work trucks because they are mandated. Auto slacks are OK if they keep working. Just my opinion. Joe D. Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218127 Share on other sites More sharing options...
Joe Ditchkus Posted November 23, 2013 Share Posted November 23, 2013 I forgot to mention auto slacks are about 3 times the money. Joe D. Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218128 Share on other sites More sharing options...
Gmerrill0516 Posted November 23, 2013 Share Posted November 23, 2013 looks like some good advice. The cans on my 815 are spring brakes but the yokes are welded to the side of the rod sticking out of the shaft. It looks real tight between the frame and the wheels and the centers don't quite line up. I intend to find or make up something a little less crude. Can anyone say what the issue is and offer a solution? Thanks and glad to see another guy back in the fold.Greg Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218129 Share on other sites More sharing options...
ThaddeusW Posted November 24, 2013 Author Share Posted November 24, 2013 I forgot to mention auto slacks are about 3 times the money. Joe D.Boy, you ain't kiddin. I took a look and see that manuals are about 20-25 bucks each while Gunites are around 80 each and Bendix around 90 each.Think ill stick with the manuals for now. Makes sense as with the low miles I wont be adjusting them very often.Thanks for the input. Quote -Thad What America needs is less bull and more Bulldog! Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218158 Share on other sites More sharing options...
farmer52 Posted November 24, 2013 Share Posted November 24, 2013 Boy, you ain't kiddin. I took a look and see that manuals are about 20-25 bucks each while Gunites are around 80 each and Bendix around 90 each.Think ill stick with the manuals for now. Makes sense as with the low miles I wont be adjusting them very often.Thanks for the input.Ron (39 Baby Mack) will adjust them if you visit Gerhart's. He did my MH but I am still waiting for the invoice. 1 Quote Ken PRR Country and Charter member of the "Mack Pack" Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218176 Share on other sites More sharing options...
thomastractorsvc Posted November 24, 2013 Share Posted November 24, 2013 looks like some good advice. The cans on my 815 are spring brakes but the yokes are welded to the side of the rod sticking out of the shaft. It looks real tight between the frame and the wheels and the centers don't quite line up. I intend to find or make up something a little less crude. Can anyone say what the issue is and offer a solution? Thanks and glad to see another guy back in the fold.GregCan you get a picture I don't understand what you are getting at, unless you are saying someone tack welded the yolks to the threaded rod Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218236 Share on other sites More sharing options...
Mike Posted November 24, 2013 Share Posted November 24, 2013 Can you get a picture I don't understand what you are getting at, unless you are saying someone tack welded the yolks to the threaded rodThat is the way I felt also, I did not understand.mike Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218237 Share on other sites More sharing options...
Gmerrill0516 Posted November 26, 2013 Share Posted November 26, 2013 Can you get a picture I don't understand what you are getting at, unless you are saying someone tack welded the yolks to the threaded rodYah that's what I was attempting to write. The yoke is welded to the side of the rod rather than screwed onto the end of it. It's to accommodate the apparent offset between the can centerline and the adjuster centerline...looks funky and might make an inspector nervous. Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218383 Share on other sites More sharing options...
thomastractorsvc Posted November 26, 2013 Share Posted November 26, 2013 has the wrong slack adjuster, yes not dot approved Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218433 Share on other sites More sharing options...
Gmerrill0516 Posted November 26, 2013 Share Posted November 26, 2013 has the wrong slack adjuster, yes not dot approvedSo is the cure to buy new brake cans with slack adjusters as a set? Does that fix it? I've never purchased this stuff before...(rookie)Thanks Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218462 Share on other sites More sharing options...
39 Baby Mack Posted November 26, 2013 Share Posted November 26, 2013 Ron (39 Baby Mack) will adjust them if you visit Gerhart's. He did my MH but I am still waiting for the invoice.Invoice to follow!Ron Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218464 Share on other sites More sharing options...
thomastractorsvc Posted November 26, 2013 Share Posted November 26, 2013 They all sell individually.Since I cant look at it, my thoughts are you may want to replace everything.The brake chambers might be able to be reused if they are long enough that you can cut off the old welded on yolk and add new ones with the jam nut, but chances are they will be to short and for the cost of that stuff may not be worth the effort.They should look something like this one Quote Robert"I reject your reality and substitute my own." Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218469 Share on other sites More sharing options...
Gmerrill0516 Posted November 27, 2013 Share Posted November 27, 2013 Yes, that is what I need. When the time comes I'll bring a set up with me and I can lay it out and match up the correct offset adjuster to work with new cans. Mine work well but are rusty and for not too much money it will be right and beyond question.Appreciate the information very much. ThanksGreg Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-218560 Share on other sites More sharing options...
Maddog13407 Posted November 30, 2013 Share Posted November 30, 2013 I have seen a flat homemade adapter plate bolted to the brake chamber bracket with one bolt from the chamber and the other t the bracket then use the offset slack. seems to work. someone on here has a picture of it. Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-219115 Share on other sites More sharing options...
Gmerrill0516 Posted November 30, 2013 Share Posted November 30, 2013 This is what they look like. The cans are real tight in there mounting. The guy had told me they had to rotate the clamps that hold the can together to vet the ends with the bolts to clear the wheel and drum. Any way I'll pull a set and bring it with me to the parts place and hopefully a standard set up will replace this mess without any modifications.ThanksGreg Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-219239 Share on other sites More sharing options...
BC Mack Posted December 1, 2013 Share Posted December 1, 2013 good photo....that modification would have a dot guy busy filling in your ticket..!!!looks like you need to consider an offset slack adjuster as there doesn't appear to be room for a longer s-cam.. picture was posted earlier IIRC.not much room there..!!!BC Mack Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-219272 Share on other sites More sharing options...
gearhead204 Posted December 1, 2013 Share Posted December 1, 2013 ive seen both offset slack adjuster arms and off set clevis and since slacks come in different lengths and that's obvious the slacks been changed. I'd be for finding a proper parts list for that setup. as for having to turn the clamps I remember are 87 value liners having smaller chambers 24 or 27 they also did some steeped chambers I don't know about the b models. I'd say do a little home work first to get it right. (too damn many lawyers in this world) Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-219291 Share on other sites More sharing options...
Gmerrill0516 Posted December 2, 2013 Share Posted December 2, 2013 Thanks for the help. I'll have some conversations with Watts Mack at some point when the budget is less constrained. Maybe they can tell me. I've got the factory paperwork on the way too although if it's like the 49 L model the numbers don't mean anything anymore. I can always talk to the local guys as there are a bunch of the 80 series trucks in New England and I can take some pictures and ask some questions of part numbers if they might know.I guess it's good I asked...the more I read here the more I learn that the DOT and local constabulary frown upon inferior equipment with a large money grab! Thanks guysGreg Quote Link to comment https://www.bigmacktrucks.com/topic/33425-im-back-and-need-new-chambers/page/2/#findComment-219478 Share on other sites More sharing options...
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