semi-ot: Air brakes on 83 ford F8000 truck

A chap I'm doing work for needs a brake job on the rear end of his 1983 ford f8000. I was going to order the shoes from NAPA tonight, when I realized that they offer them in two sizes: 15x6 and 15x7. Any idea which one I should use? The truck is a single-axle dump truck, with air brakes and dual rear wheels.
I appreciate any help, guys.

It might be a good idea to measure the brake drums.

give them the vin number and the gvw,they should be able to get the right size

Good chance that a 30 year old unit could have the rear axel changed..Just take a ruler and measure the width, the 15 is the drum diam. which is constant on both sets. My bet would be the wider shoe but it could be a light wt 800.
I just hope NAPA has the shoe. Some fords long about then used a real off brand wedge brake set up with shoes linke nothing else..Good luck

i do my own truck brakes, with air brakes, there are more than 2 kinds, take the truck apart and take 1 of each of its shoes into napa with you, also get new drums, on a big truck using old drums with new shoes will result in less than satisfactory brake performance under a load, as the new shoe will not contact the drum all the way across due to the old shoes and drums having developed a wear pattern, do not try to have the drums turned, they will overheat and possibly fracture when they get hot if you do, the usual rules of thumb for cars and light truck brakes do not apply to air brakes on big trucks, been there, done that, luckily im around to tell the story

Start early.... pull the hubs and see what you have in there as it ~could~ be ANYTHING. There's Rockwell, Eaton, Freuhauf and probably a couple more ~styles~ of shoe in a bunch of different sizes... so just investigate and measure. Then get what you need along with new wheel seals. You also want to inspect/repair/replace as needed: the maxi cans, the slack adjusters, the S-cam's AND bushings, the spring sets as well as the cam rollers and the shoe pivot bushings. The bushings are probably seized.... Also measure the drum against spec. You do a brake job on that thing, you want it done right... or it's on your head if he gets in a wreck. If in doubt it's better to replace...

Rod

why would you go to napa??? they are not your run of the mill brakes. the brake shoes on trucks are rated by wt. and some shoes are soft and some are hard. the wrong shoes will get you parked by the DOT if they do not meat the wt.. go to a truck parts shop that knows trucks and air brakes. Road eq. is one place i use all the time

I get a 50% discount at napa. Plus, they like me there.

why the wheel seals? Even if they don't leak?

they will if you pull the hubs but if you can just pull the drum then you can save them

Because if you don't replace them they are guaranteed to leak and you will get to remove the wheels again to replace them.

Always replace a seal if you disturb it. As far as pulling the drum.... I guess you need to figure out what a seal costs VS your time... and if it's your time (free) VS his money, I'd probably opt for him buying 2 new seals. Really, it takes a lot of time to pull wheels and drums. Not so much time to pop the axles and pull the hubs unless they're bud wheels and you have 1" air gun... then you get into the chance of needing to change rusted studs that won't thread out...
If it's got Dayton/spoke wheels... and you remove them, and you're not practiced at setting them up, you get into a lot of time to set them straight.... so it's easiest to just pull the hubs. If you don't have a dolly or pallet forks on something then a greased sheet of plywood works good enough to slide the duals/hubs on intact.
Beyond that, it's just good practice to change an old seal on something like that.

Rod

napa as well as carquest have a large line of heavy truck parts, brakes parts as well as air line stuff and air valves, just ave to have somebody in the store that knows his truck stuff most is not compatible with the young kid at the counter, our napa and carquest keep most major stuff in stock due to the large number of dumps, trash, cement trucks ect,

Take the tires off if you have outboard drums.Release the brakes on that wheel by backing off the slack adjuster.Take the drum and brake shoes off after taking a picture of it on your phone if you can,and take the brake shoes to a store that sells truck parts.
Probably you should call Napa and ask what they want for their shoes.Then call a truck parts place.If brakes for one wheel are over 55 dollars for a boxed brake shoes kit with new springs then you probably are getting ripped off.
I cant ever remember working on a Ford truck that big.Maybe, but long ago.Basically most trucks like KWs ,Peterbuilts,Freightliners have 2 styles.Both quick change but have different size holes and different rollers,springs and stuff.Rockwell and Eaton or there are other names for them,I just dont remember what the names are.

There are 3 different grades too,soft,medium and hard.Soft being the cheapest,hard being the worst on the drums because they have metal in the mixture they are made out of.After thinking about it,that 55 dollars was last year,maybe the year before.Napa or OReillys could be alright,but I would almost bet that they are higher priced than a truck parts place like Inland,or Truck Pro,or others.Evem MHC Kenworth,Freightliner,Peterbuilt,International and other truck companys sell parts.Kenworth has sales all the time and could beat even a truck place.Especially on batteries.That would all be right if Ford doesnt have some wierd kind of brake shoe that only they have.I doubt it,but anything is possible especially with Ford parts.

When they still made Ford big trucks,Ford sold parts for all kinds of trucks.They were reasonably priced too.I bought some stuff from them before,but since they have been taken over by Sterling I dont know if they still sell parts or not.Maybe they do by whoever bought Sterling.Even GM sold truck parts but they were usually high priced compared to the others.All of them are high priced if they have a part you cant get anywhere except from them.

Napa and ORiellys depend a lot on how much truck stuff they keep.Ive been surprised by them before,but usually they didnt have what I needed.A good parts man can get you about anything if you can get him to do it.I have got stuff from a truck place that auto parts claimed they couldnt get.I have no idea why,and it was cheaper than the other place if they had it?I dont think it works the other way.Napa and Oriellys are going to be higher on the truck parts probably.With your discount its usually higher than a truck place still.

I had to have some steer axle brake shoes one time and the truck place was out of them.Oriellys had them but almost 3 times more than the truck place.Napa probably is no different.I get a discount too.

To do the job right you need to get a drum gauge or calipers and measure the drum s for wear and being out of round or grooved badly, they may need to be turned or replaced .Throwaway size on 15" drums is 15.120" .You also want to check S-cams and cam bushings for wear .Plan on replacing spring kits, and wheel seals if you pull the wheels, drums and hubs all together. Best way to get the right shoes is pull drums off and measure - 15" is drum diameter, 6 or 7 is shoe width - maybe take a shoe with you to the parts place. Usually rear drums are 16 1/2" on rears. You may want to get one side apart as there are alot of possibilities for shoes in that age - old Rockwell style with anchor pins to drive out, Q or Q plus quick change shoes - I reccomend going to a truck parts supplier if you are unfamiliar with brakes of this size -not only for price as others mention but to deal with people familiar with heavy truck brake parts. If your NAPA has anyone that knows truck parts they should be OK. Napa around here is trying to get into heavy truck parts more all the time.

Thats actually a real good question.There are reusable seals.A long time ago you had to change the seals every time you pulled the whole hub,but ever since the late 1980s they have had reusable seals.National seals are like that if I remember right.Probably are other brands like that.You might or might not have the reusable kind.Plus most trucks since the 1990s have out board drums which means you dont have to take the hub off,just the tires and release the brakes and one good hit with a sledge usually knocks the drum loose.Pull it off and get to the brake shoes.

Crawl under it with a light and look at the condition of the seals,if they are dry then pull the tires and take off the drums and change them like that if you have outboard drums.If they are wet with oil,pull the whole hub with tires on it and put in a new seal along with brake shoes.While you are doing this,pull the breather out of the axle and clean it out and put it back in.You dont want to ruin your new shoes with oil leaking on them and clean breather in the axle is a good way to keep that from happening.

There is nothing wrong with turning drums.There is a specification of how thick they need to be.If you dont cut them thinner than that specification they will work fine.Ive turned lots of drums on big trucks and never had a lot of trouble with drums fracturing.Usually if you look at pieces of a broken drum,its when they are a lot newer.They fracture because of being hit with a sledge hammer or a flaw when they make them.You dont see them break a lot from being worn out,but they can.If you cut them too thin then you could have trouble.You might be able to turn them 2 or 3 times before you got them close enough to spec to throw away.Some last better than others.

If you put new shoes on old drums,just like if you did your car the same way,it would wear the shoes into the grooves and work a long time.Its best to replace them if they are chewed up bad,but it does reduce the stopping power until you get them worn in.There is nothing wrong with putting new shoes on and using worn drums.Its done all the time by everybody running trucks.If you constantly run steep mountains then you want all the brakes you can get,and they even have mountain brakes.On flat ground mostly, regular brakes will work real good if they are adjusted right,have good pads,and drums not worn out of specs.Overheating is not so much of a problem on flat ground.Its those long downgrades that heat up brakes.but regular brakes adjusted good will work for that too as long as you know what you are doing.

I just remembered that to replace the seals you need a seal driver so you dont mess up a new 20-30 dollar seal.You might have to borrow one from the parts place if you have to.

I also reread that it was a 1983,I missed that the first time.While it still could have outboard drums,the chances are less likely,and thats only if it has Bud wheels.If it has Dayton wheels its probably quicker to take the axles out and take hub,tires and all off and probably replace the seals.

If the truck is used a lot where it would have had brake shoes replaced in the last 10 or 15 years,theres a good chance somebody converted it to quick change brake pads,which is good for you.If not then you have to either cut the pins out with a torch,beat them out with a sledge,or there is a press like tool that might take them out made by OTC just for that job.Maybe you can rent it if you need to,and do the next guy a favor and switch them to quick change shoes if possible.I may be wrong about this,but I think all that are available now are the quick change type anyway.

oh jeez... this job has gone way the heck out of my skill level, hasn't it?

It's not that difficult if you just go about doing it and replace what needs replaced.
Seals and sleeves can easily be driven with an appropriate size piece of pipe.
The shoe pivot bushings can be driven out with the application of some heat to the housing, then drive them with a sledge and socket. Brake jobs are just bull work. Not overly technical work... just bull work.
The stuff is simple. Just make sure it's in good working condition... and MAKE SURE the maxi cans are good. Not leaking. Not rusted through and the springs apply correctly.
I'd much sooner do a brake job on a tandem truck with s-cam brakes than ANY small vehicle with hydraulic drum brakes...

Rod

Its not so much that its past your skill level.Its tools that you need.If you dont have a set of seal drivers for trucks,a pin press for brakes,or even a torch,you might get the job done,but it will maybe be real hard to do!

A truck that doesnt get used much,and if the seals look good enough you might get away with reusing the non reusable type if you are real careful and dont beat them up a lot when you put them back on.If theres a lot of rust and dirt on them and they look bad then you need to replace them,with a seal driver and clean up the mating surface for the seal with emery tape.

Like somebody said on a truck that old there is a chance that its been changed anyway.

(quoted from post at 21:33:36 05/07/10) i do my own truck brakes, with air brakes, there are more than 2 kinds, take the truck apart and take 1 of each of its shoes into napa with you, also get new drums, on a big truck using old drums with new shoes will result in less than satisfactory brake performance under a load, as the new shoe will not contact the drum all the way across due to the old shoes and drums having developed a wear pattern, do not try to have the drums turned, they will overheat and possibly fracture when they get hot if you do, the usual rules of thumb for cars and light truck brakes do not apply to air brakes on big trucks, been there, done that, luckily im around to tell the story

Click to expand...

Brake shoes are available with over size pads to compensate for turning the drums. As long as the drums can be turned and are in serviceable condition, the use of proper shoes when give as good of performance as all new parts.