I have a squealing sound when I apply the brakes. I'm fairly certain it is coming from the rear because I did the front brakes when I did the bearings a few months ago. This is my first truck and so this is my first time doing the rear brakes. How do I get to the brake shoes? I'm down with remove the wheels... but not sure where to go next. Does the drum come off like the front? Or is it a hub? Do I need to remove the axle to do this job? Any advice is very much appreciated. 5 studs Does this brake lining look like it needs replacing? This is the lowest out of them all from what I can see. Its wet from being washed with the pressure washer, couldn't see anything before that.
If the lining is that thick all the way across the shoe, it doesn't need replacing, and as a matter of fact looks near 90%. You could have a problem where the drum is worn unevenly, and the middle or inside of the shoe is thinner. I generally replace them when the lining is between 1/4 and 1/8" thick (4-6mm, for you metrically thinking fellows). To get the brake drum off, you unscrew the 12 nuts on the axle until they are even w/ the ends of the studs, then whack the center of the axle w/ a 10 pound hammer untill the axle pops out. You can leave the tires on the hub, or take them off, your choice. Behind the axle you will find the wheel bearing nuts, remove the outer bearing and slide the hub off, Then put A NEW SEAL in the hub before reinstalling it. You should also put some gear oil in between the bearings, since it is possible to burn up the bearings before the oil gets from the rear end to the inner bearing. Good Luck, Mitch
Thanks Mitch, So you think the squealing must be coming from somewhere I can't see. Would it be worth me backing of the rear brakes one at a time and driving around a bit to work out which one is the culprit? I rather not pull them all apart if it is only one that is worn unevenly.
Well Nick009, since you're new to trucks, you need some tips. Brake squeal can come from shoes or drums, hard to say just which, I lean more toward drums, but anytime I service either, I'm putting new shoes and drums on, ain't worth doing half way, result is problem solved. Shoes are easy to say "they done, replace them", but drums are equally important, as for the friction surface, heat cracks kill the braking surface, replace the drum. As for knowing when shoe is done, look at the mid point of shoe, you'll see a gap in the shoe, the friction lining will have a vertical gap where bonded to metal part of shoe, then the gap in the friction lining will convert to a "V" shape in friction lining. Here in the US, when that "V" is no longer present in the friction lining, the shoe is done. As for your wheels, those are known as Dayton rims. If you have to remove wheels, loosen nuts, but leave nuts on the studs a few threads, whack the rims with sledge to dislodge clips. If you remove nuts completely and whack rim, clips will fly across shop, something mitch should have told you, and I thank you for the opportunity for me to bust his chops. And if you do have to remove the drums, you have to back off the slack adjusters. If you're working on drive axles, at least one of those axles, if not both, will have dual chambers (spring brakes) on it. To back off slack adjusters you'll have to have system pressure, push parking brake release knob on dash, then back off slack adjusters. You won't be able to back off slack adjusters on axle that has parking brake applied. As you suggested, backing off slack adjusters one wheel at a time may reveal your squealing culprit, as long as you have the truck unloaded, don't see a problem doing that.
Thanks for all the advice willie59, I check out the "V" shape and they all look pretty good. You're totally right there, they wouldn't budge with the park brake on! I backed off one of them and went for a drive, there was no squeal so I went home and tightened it up again and went driving again and there was still no squeal. Would I need the brakes to warm up before the squeal starts of perhaps I have set the slack adjuster too loose? I pulled one of my wheels off because one of the cleats looked like it was too close to the air filler. When I washed down some greasy spots I noticed bubbles coming out of one of my air fittings. There were more bubbles coming out but I flipped the olive upside down and then tightened it and the pictures shows the significantly fewer bubbles after the tightening. Can anyone tell me what this air fitting is called so I can replace it. The australian version would be awesome if possible. Could you also explain the recommended method for installing them. I've done lots of plumbing with copper but no work on air pipes before. When I was putting my wheel back on I noticed something else. My cleats don't match... I saw at least 3 different cleats on the one wheel. And a fourth on another wheel. Which are the correct ones for my truck? Many thanks, Nick
Since you're a relativeley new truckie, do not disassemble the reasr section of a parking brake chamber! The springs are very dangerous.
Thanks Ben, I didn't know that.
No sweat, also, I don't think I've ever seen a truck that the brakes didn't squeak. Our local transit authority has a machine that mates the drums to the shoes before installation so break in isn't required on new shoes, and I think those squeal more than any others! As far as the wedges, pick the ones that let the nut sit squarely on the wedge without the wedge bottoming on the hub. I don't think its really hurting anything the way it is, old trucks get mismatched though by using stuff from the "magic parts bucket" under the bench. Do you have any pictures of the whole truck for us to admire?
Here it is! Any thoughts on that air fitting, what are they called?
I'm not sure brake squeal is necessarily an indication something is wrong. Is it really a squeal or more like a howl? The Ford Louis' were known for the brakes to howl, I drove a bunch of them delivering freight. A trick to pulling the rear drums off is to leave the wheels attached and jack it up enough to slide a smooth greased steel plate under the tires. Lower the truck onto the plate then jack it again just enough to take the weight off that wheel. Undo the axle, remove the spindle nut and you can slide the entire wheel assembly off the truck towards you. Reverse the procedure to reassemble. They also make wheel dollies that have a small hydraulic jack to do a similar thing, they are several hundred dollars. DO NOT disaasemble the parking brake cans unless you are absolutely familiar with them!! They are under extreme spring pressure and you can (will) be seriously injured!
Ok I'm not going anywhere near those brake cans, I think they call them break boosters over here. My truck has 3 or 4 different looking boosters, some have been painted and some have been put on since the last paint job. Because of the differences in appearance I figured they were a throw away and replace part. But I really do appreciate this sort of advice. Its the sort of thing that you need to know but no-one will tell you because they assume you know and don't want to state the obvious. Thank you!! That's pretty tricky Steve. Now that I understand how to replace these shoes and or drums I'm thinking it might not be the sort of thing I can do on my gravel driveway. I did the front brakes when I did the bearings but pulling the axle out seems a lot more...well heavy for a start. From the sounds of things I should be able to tolerate a bit of brake squeal as long as my shoes have the "V" in them. I only went down this road because a bloke mentioned I should "look at my brakes before I wreck the drums" when I was picking up a load of sand. I think I will just keep and eye on them for the time being. I'm not driving it day in day out currently. At most it would be 3 jobs per week. Thanks again for all the help! nick
Most people call them brake boosters around here too. Most manufacturers call them brake chambers. I agree about not taking the clamp rings off of them. I started in the era when we rebuilt them on the truck, and have done a bunch, but now if I find an old one that has a bolt type ring on the spring end, I usually replace it when it starts leaking. I set the back of one up in the vise pointing out the shop door and rigged something to take the cage bolt out remotely. The piston flew about 80' and stuck INTO an oak tree. Those fittings are called compression fittings. They are sized by the outside diameter of the tube. The only difference on using them on nylon airbrake tubing and copper is that there should be an insert that goes into the end of the nylon tubing. Some times it is pressed into the fitting, but if not you can buy them that just slip into the end of the tube. To fix that leak you probably only need the insert and a new ferrule (guess thats what you called an "olive"). If you can take it apart and slip the ferrule off, the fitting wasn't tight enough. About the wheel wedges, like Willie joyfully pointed out, never just unscrew the lugnuts all the way off. Back the nuts off untill they are about flush with the end of the stud, then hit the side of the tire w/ a sledge hammer, or tap each wedge individually with a smaller hammer. You just need them to move a little before you take the nuts off. They don't often do it but they can store a lot of energy. I have heard the noise, and run out in the shop to see the holes in the sheet metal wall where they flew by a helpers knees. About the wedge length, the textbook answer is that any wedge length where you can tighten the nut to 60% of the torque needed before the heel of the wedge hits the hub is acceptable. Mismatched wedges are very common on older trucks. When take a hub off on concrete I sometimes use a piece of roofing tin w/ a little gear oil on it like Steve said, but on gravel I take the tires off and have a helper help me lift the hub by holding one end of a little piece of rope the is between the hub and drum, unless I had an extra bowl of Wheaties that morning. I agree with others, unless the shoes are worn out, I wouldn't worry about some squeal. Good Luck, Mitch
It's not really too bad. Yup... behind every nut, there's a little external collet that removes all free-play between the drum and axle... that's why you whack the center. It's also why you leave the nuts... Mitch knows... A little dust or a tiny rock can cause your brakes to make lots of strange noises, from the pictures at least... your brakes look fine. A few links... ftp://164.106.79.2/Instructors/Rscoville/Bendix/Dual Brake Chamber.pdf http://www.mto.gov.on.ca/english/handbook/airbrake/section4-2-0.shtml The Speedi-Sleeve®... http://www.skf.com/files/344136.pdf And for grandpa... :tong... the reason the word "collet" is blue; it's a click-able link. OCR...
From the look at the pics .... there are no dust shields covering the brakes (on the back side) .... so its very likely that theres a tiny rock or some sort of crap in there too ???
I'd say it would fall out just as fast as it fell in. All of our trucks squeal and really loud from time to time. I say don't worry about it is the most likely course of action. It's the cheapest, too.
What we honestly used to do about dust shields when I had a bunch of dumps was: If we had trouble w/ little rocks getting in the brakes, we looked to see if it had dust shields. If it did, we took them off. If it didn't, we put them on. It sounds stupid, but some trucks or trailers did better w/ them, some did better without them.
Thanks Mitch, maybe I'll try tightening it a bit more then, the leak was definitely less after I flipped the ferrule and tightened it. I'm also going to buy some of those compression fittings so I have some spares Ok that makes sense. On some of them the heel is 5mm (0.2") away from the hub when the nut is fully tightened. So I should probably look at replacing those hey? Cool, hopefully I won't need to in the near future but I guess I'll go for the gravel method given my situation. Great links OCR, thanks for those. I always wondered how to move a truck if the air stopped working. Where do you use the speedi sleeves? Sorry its not obvious to me... No dust shields on this one, I didn't know there was such a thing... So I think I might have damaged one of the boosters with my high pressure washer. It seemed to be leaking a lot of air after I squirted it. I'll take a photo of it in the morning when its light. I'm a bit worried to even look at it after all the warnings! Whats the best way to safely replace it and at a guess what do these units cost?
Is it just leaking at the airline or from the can itself? Spraying them shouldn't hurt anything! Brake cans aren't too awefully expensive. And if the pushrod is in good shape you can usually just put the piggyback on instead of the whole can. The v band clamp closest to the slack adjuster and pushrod can be safely removed and a new diaphram and park brake section installed. There is a small return spring in the front apply section but its not very strong.
Not necessarily a small rock can jam or get stuck on the back side or should I say between the drum and the shoes .... and for some stupid reason they never just "Fall OUT" WE up North Never run without dust shields ..... too much Off Road (non pavement) roads, to take the risk of getting the extra crap into the brake causing premature wear .... If I was just running asphalt I prob wouldn't use them either ..... to each his own ... Jmho
Good luck
Well I fired it up this morning but the leak seems to have gone away. I tried it with and without the park brake on. The other day when it was leaking the park brake was off. So Mitch my next question is how the hell to I work out 60% of the torque with a rattle gun or a 5' pole? My rattle gun has 4 different torque settings, perhaps I could use that somehow. I picked this up for $100 on ebay Ingersold Rand 2135timax