I am moving on to another phase of my '49 1 1/2 ton 4408 flatbed rebuild. I found out the back brakes were locking up. Upon inspection I found both rear brakes need rehab for various reasons. It took quite a bit of work to pull the emergency brake cables off but I got them cleaned up. I need to pull the hubs and drums to get to the brakes. The shop manual says the 48 - 50 require the hub and drum to be pulled as a unit but I can't for the life of me see how they come off. I pulled the axle caps off and that doesn't get me anywhere. Do I need to pull the axles first?
RE: Rear Hub/Drum Removal on 1 1/2 I got 'em off. You do have to pull the floating axle first; that's easy. Then there are two nuts and a lock ring behing the axle splines. The splines engage the axle to the hub. Now I'm off to fix the brakes on the rear. They need wheel cylinders and adjusters fixed, drums turned, etc.
RE: Rear Hub/Drum on 1 1/2 _DON'T_ turn the brake drums ! DO NOT make this common mistake ! . Only if they're so out of round that you feel brake pedal pulsation . If you don't belive me , go ask Bob Adler , a world famous old truck guru . -Nate
RE: Rear Hub/Drum on 1 1/2 OK. Any reason why not? One of my drums has some pretty noticeable scoring. The other is glazed. That's the one that was locked up. I plan on going through the wheel cylinders and giving everything else a thourough cleaning since they are caked with black brake goo. I did not feel any pulsing in the brakes when I drove it. The left brake locked up while it was sitting with the emergency set. It seems it was just due to the cables being gunked up and the mechanisms being full of crud. Also, the adjusters are not working and one is missing. I will need to find one. I'm not familiar with Bob Adler.What mountian does one need to climb to find him? As always, thanks, Nate.
RE: Turning Drums O.K. , here's the deal : There never was much metal in these old brakes drums so each time you cut them (turn) you make it so the get heat fade , faster ~ a _VERY_ bad thing if it happens to you , brake drums need the metal thickness to dissapate heat and once you turn it , the heat has nowhere to go so you get brake fade , this is when the harder you push the pedal , the faster the truck goes downhill... I've been to many many brake clinics over the years , back in the day when the same folks who MADE the brakes , gave classes for mechanics so you could do better quality work . Scored drums are bad yes -but- the new shoes will bed into the scoring in a few hundred miles so then the wear is equalized and not a problem . if the scording is really rough you can smooth it up a bit with 600 grit sandpaper . If it really , _really_ deep it is time to begin looking for new drums . You can only turn a drum once or twice anyway before it goes past the leagal thickness limit nayway and since you're dealing with 50 year old parts it's prolly close to that diameter from normal use anyway . BTW : wire brush the parking brake cables as clean as you can then soak them in altifreeze for a week or so and they'll be lubed for life , the first few times you pull it back & forth to draw in the antifreeze will be a bugger but keep at it . Bob Adler is a world famous old truck guy who's written perhaps the best book on AD restoration , of course I don't have a copy of it.. -Nate
RE: Turning Drums & cable lubing Great info, as usual, Nate. Thanks. Heres what I did before I got your tip on using antifreeze... I took my E-brake cable tubes and soaked them with Penetrating oil on the outside for about 10 minutes. Flexing the tubes a little will speed penetration. While I was waiting, I put some down both entrances for the cables into the tubes. The tubes are really tightly wrapped wire like a spring so the Penetrating Oil will work its way between the windings. Put the cable tube in a vise using only enough pressure to hold the tube still; you don't want to crush or deform it. After the 10 minutes, I carefully began turning the cable itself in the tube. Turn in the direction that tightens the cable twist. Do not turn the other way which will unwrap the brake cable and ruin it. I used a screwdriver in the clevis to get leverage. It will almost immediately begin turning the entire cable in the tube and you can see it turning the whole cable. After making several comlete turns you can start pulling on the long end of the cable and then the short end to get the cable sliding in the tube. Once this was sliding back and forth I liberally kept shooting penetrating oil on the cable, sliding it back and forth and then wiping with paper towels to get all the gunk off. Once the paper towels were coming off pretty clean I soaked the cable tubes with oil by flooding the cable and pulling it in and out of the tubes. Then I wiped off the excess oil. I just used 30 wt engine oil. By the way, the book recommends lubing the cables something like every 1000 miles.
RE: Pbrake cable lubing The deal is : oil will evaporate in a year or less and you'll not be thinking about re-lubing the cables untill they sieze again . -Nate
RE: Pbrake cable lubing That's a good point. I spent all this past weekend rehabbing the rear brakes. The wheel cylinders were all messed up... adjusters were frozen, adjuster - brake shoes bolts were frozen, emergency brake mechanisms were frozen, wheel bearings (both inner and outer) were dry as a bone. It took a day per side to rework and clean everything, replaced cylinder seals, polished the pucks, freed up the seized parts, etc. Did I mention the left cylinder didn't have a drop of fluid in it and the bleeder was locked up so tight I had to heat it with a torch to get it out? I still have to flush out the old fluid in the system, hook up the lines and bleed and then re-install the emergency brake cables and adjust. I bet this baby will stop good when I am done. At least for a while.
RE: Brake Service Notes I'm sure you know to lightly lubricate all the linkages and adjusters etc. , where the brake shoes touch the backing plates and so on with Lubriplate # 107 Lithium based brake grease but never any rubber or hydraulic parts , McKay makes a GREAT brake Assembly Lube that if used to lubricate the rubber cylinder cups before assembly , will greatly increase the life of same . You should flush out the steel lines with alcohol or aerosol brake cleaner before re-connecting them to the wheel cylinders or master cylinder , sharply bend each rubber hoes and if you see even the _tiniest_ crack appear , change them out as they deteriorate from the _inside_ out , if the blakc outer housing isn't shiny , I'd change them out even if no cracks as they're a _SERIOUS_ safety item and when one pops , you're in trouble at the worst possible time , guess how I know this ? . You can get cheap syringes from the drugstore (BIG ones) and use to flush the brale lines with alcohol or clean brake fluid , you must not connect the freshly rebuilt cylinders untill clean fluid runs out the open lines when you're flushing and flush with clean brake fluid after you're all done cleaning them . -Nate
RE: Brake Service Notes I did lube all the linkages in the brake shoes, that was a no-brainer. I intend to flush all the lines with clean brake fluid. I like the idea of using alcohol first. I suspect there is a lot of crud in the lines that has absorbed water vapor over the years. I sure don't want to contaminate the wheel cylinders with old crud after all the work I put in. I haven't even hooked the brake lines back up yet; not until I flush them. On the rear-end all the lines are solid, so I don't have to worry about the rubber thing. That will be part of working on the front brakes... next step.
RE: Rear Brake Flex Hose Ah ; There is _ONE_ flex hose to the rear end ..... You'd be amazed at how this stuff is _not_ a ' no brainer ' to the average DIY'er ~ one guy had unending troubles with his hydraulics untill I asked him if he'd touched the rubber bits with -anything- other than brake fluid ~ he replied , ' why yes ~ I rubbed penetrating oil on all the brake cups before assembly ' ~ God alone knows where he got that idea but he had to completely flush out the entire system with alcohol and replace ALL the rubber in the entire brake system to repair the resulting contamination and problems it caused.... -Nate
RE: Rear Brake Flex Hose I "finished" the brakes on the rear yesterday. You are correct, There is one small piece of rubber at the back but I was referring to the connections to the backing plates versus the flexes on the front wheels. No matter, I checked mine yesterday and it was fine. The problem I found was that the adjusters work poorly. It seems that they are either worn on the nubs or they spin on the bolt. One is missing altogether. Two of them ended up getting a tack weld to solid them up on the bolt. That helped, but I also had to tack some of the nubs that were worn down so they would engage the wheel cylinder cups. Even that didn't fix them 100%. I would like to find a source for the factory parts rather than make a fix myself on the milling machine, but I am just starting that project. I ended up getting most of the wheel adjustments correct on the back, but am not 100% satisfied. I need to tackle the fronts and try adjusting them up. What I am seeing is that I don't quite go all the way to the floor on the first stab of the peddle, but the second stab is very good after about 2" of travel. I suspect I am pushing the shoes out with the first one and then doubling back with more fluid on the second to finish the movement. That seems to say the shoes are not adjusted close enough to the drums. Since I know the backs are OK, the fronts must be the culprit. I did find that both front wheels turn much freer than I would think which seems to support my idea that these shoes need adjusting. Like I said, I haven't done anything to the fronts. I only attacked the backs because the left one locked up. I am still in the mode where I just drive it up and down my driveway (about 200 feet long) not out on the road until I have more faith in the brakes. Any idea on rehabbing tbe rear adjusters? I want to keep it as close to stock as possible, so disks or new systems are not in the running.
RE: Rear Brake Adjusters Can you take the old adjuster to your local brake jobber ? they may be able to match them up with new parts as the Bendix brakes were used into the 1970's..... Lee still makes a LOT of early brake poarts & kits for hardware. Of maybe find someone over on The Stovebolt Page who can help you . -Nate
