1972 F250 12"x2.5" Bendix rear drum brake rebuild: advice?

[robroy]

Good evening!

Before taking #50 out for a test drive with its new engine, I'd like to make sure the rear brakes are completely safe. They were rebuilt last by my father Hugh in 1996 and haven't been touched since. I watched him do the rebuild but it went "in one eye and out the other."

The brakes have two symptoms: there's too much pedal travel before they kick in, and over time, they seem to un-adjust themselves.

I'm guessing that the pedal travel is simply a matter of adjustment and/or bleeding the brakes, so I doubt there will be any mysteries there.

I heard from my father years ago that he thinks he installed the auto-adjusting hardware incorrectly, which has caused the adjusters to gradually increase the shoe clearance instead of decreasing it. So I'll be investigating that while I'm in there!

In addition to making the brakes safe, I'd like to get the parking brake working nicely!

Y'all can click on any of these images to view much larger, high definition editions.

Here's how things looked when I began today.



Oddly, I don't have access to a floor jack at the moment, so I decided to try lifting the back of the truck with a "cherry picker."



I removed the trailer hitch "ball" and grabbed the rear bumper. It looked rather strong so I didn't think I'd run in to trouble that way. Unfortunately, I realized after wards that I'd bent the bumper slightly! Oh well.



Here's the driver's side.



Then I got both wheels off.



And here's #50 without rear wheels! Note that all of the weight's resting on the wood blocks. The jack stands and tires are sitting under the bumper as safeties only.



Here are detailed photos of the drums. The driver's side drum's on the left, and the passenger's side drum's on the right. Aren't they charming?



I'm working from the 1972 Ford Truck Shop Manual, page 12-02-2; here are my instructions:



I gather from step #3 that I should be removing the eight bolts closest to the center next!

I'm sure I'll have specific questions as I get deeper in to this adventure.

Can y'all think of any advice that I could benefit from at this stage?

Thanks very much for the fantastic guidance!
Robroy

[m-mman]

To answer you question about the self adjusters YES(!) there are Right and Left star wheel adjusters.

To check a brake installation for proper function pull on the adjuster cable. (pull it toward the shoe linning, it doesnt take much)
It will pull the lever away from the star wheel. Once the cable is released the lever SHOULD contact the star wheel and move it 'one click'. When the star wheel is moved this way (pushing the side of the star wheel closest to you DOWN) it should make the adjuster move the shoes farther appart.
If this action moves the shoes closer together then swap the adjusters Right & Left.

[robroy]

Good evening M-MMan, thanks for your great reply!

To answer you question about the self adjusters YES(!) there are Right and Left star wheel adjusters.

Perfect! Thanks.

To check a brake installation for proper function pull on the adjuster cable. (pull it toward the shoe linning, it doesnt take much) It will pull the lever away from the star wheel. Once the cable is released the lever SHOULD contact the star wheel and move it 'one click'. When the star wheel is moved this way (pushing the side of the star wheel closest to you DOWN) it should make the adjuster move the shoes farther appart.
If this action moves the shoes closer together then swap the adjusters Right & Left.

Okay! Thanks for these great instructions M-MMan! When I get to that stage I'll recall them for sure.

So it didn't take long for me to get lost! I removed all eight bolts from the center area; they came out very easily with the impact wrench.



The thing I immediately noticed after removing the first bolt was a smell! By removing those bolts, did I open up the differential cavity? I'm no judge of the smell of gear oil, but it smelled pretty nasty to me.



Step #3 tells me to, "Remove the rear axle retaining nuts, adapters, axle shaft, and grease seal." Where are these nuts and adapters? Should I try to pry the plate I removed the eight bolts from outwards?

Thanks very much for the superb advice!
Robroy

[FreakysFords]

The flange IS the outer Axle flange. There's much debate on right and wrong, but I normally smack the raised portion in the middle with a 3lb hammer and "bounce" the axle loose, then just pull and remove the axle.

[robroy]

Good evening Frank, thanks for your fast reply!

The flange IS the outer Axle flange.

Okay, I see!

There's much debate on right and wrong, but I normally smack the raised portion in the middle with a 3lb hammer and "bounce" the axle loose, then just pull and remove the axle.

Okay! I take it that smacking it thusly isn't likely to cause any damage?

I also just found this article that I'll use to supplement the Ford manual: http://www.boyandjeep.com/tech-articles ... rear-drums

Thanks again for your fantastic reply Frank!
Robroy

[FreakysFords]

Okay! I take it that smacking it thusly isn't likely to cause any damage?

Not a problem. Once you get it out, removing the rest becomes visibly simple.

Good find on the link.

Frank

[FreakysFords]

That looks like an unusually good article doesn't it?

yup, and given GSequoia's attention to detail and obvious organization, his write ups should be easy for most anybody.

Frank

EDIT:

As to the bolts. I tend to replace them with "shouldered" studs anyway, so I use Perkins parts meant to hold the top of the engine adapter to the block. If you have a good NAPA or general hardware store (not a run of the mill chain) nearby, you should be able to find the bolts. As they do often get stretched from unknown removal and over torquing, it is a good idea to replace them if you're not certain about them. If you do replace them, try to keep the short shoulder that yours have, as well as the "washered" head (not as important, but will make life a touch easier).

If you go with studs (unlikely I'm guessing), then this is a great place for Nords. I use blue locktite on the hub side and Nords or double nuts (on off road rigs where ya might need to pop one in the woods) on the outside. To be honest, I've only recently started switching over to Nords, I had been using drilled nuts and tie wire on all, but Nords are a ton easier and faster.

As always, this is just my way and not exactly a given.

Frank

[FreakysFords]

Nice looking timber by the way!! As a hobbyist Luthier, and wood worker, I couldn't help but notice. What tree did that once belong to?

Frank

[robroy]

Good evening Frank, thanks for replying!

yup, and given GSequoia's attention to detail and obvious organization, his write ups should be easy for most anybody.

Excellent! I didn't realize that GSequoia wrote that; that's outstanding. I'll have to PM him to say thanks.

As to the bolts. I tend to replace them with "shouldered" studs anyway, so I use Perkins parts meant to hold the top of the engine adapter to the block.

That's interesting! I've never heard of Perkins before. Is this the Perkins your referring to? And are engine adapter and block both in the context of these Perkins engines (not anything you'd find on a Bumpside normally)?

If you have a good NAPA or general hardware store (not a run of the mill chain) nearby, you should be able to find the bolts.

Okay, I'll try then! There is a pretty good NAPA in Salinas. As for hardware stores, I've yet to find a classic, old fashioned one in this area.

As they do often get stretched from unknown removal and over torquing, it is a good idea to replace them if you're not certain about them.

Great. Since these are very old and crusty looking, I'll try to replace them then! These also appear to be grade 5 bolts, which surprised me a little bit. Don't these take the full shearing force of the drivetrain at the wheels?

If you do replace them, try to keep the short shoulder that yours have, as well as the "washered" head (not as important, but will make life a touch easier).

Do you happen to know what purpose the shoulder serves on these bolts? I was wondering about that. Also, the washer might appear to be somewhat captive on the bolt in my photo, yet it's not washered per se--it seems to be a regular (albeit unusually thick) lock-washer slipped on to the bolt.

If you go with studs (unlikely I'm guessing), then this is a great place for Nords.

Would studs be beneficial in this situation because they'd make it easier to re-install the axle? Or simply because it's easier than trying to get the first couple of bolts started while holding the axle in place?

Also, would Nord-Locks be more applicable to studs than bolts?

I already checked my Nord-Lock stash and I don't have enough of that size to use them here! I might order some, but it's a little painful to wait for such a small part to arrive (not to mention paying $10 shipping for a $12 part). I have some thick, USA-made, grade 8 lock-washers that might work instead.

I use blue locktite on the hub side and Nords or double nuts (on off road rigs where ya might need to pop one in the woods) on the outside.

Okay! I suppose I'll have a better mental picture of what constitutes the hub side versus the outside as soon as I get it pulled apart more deeply.

To be honest, I've only recently started switching over to Nords, I had been using drilled nuts and tie wire on all, but Nords are a ton easier and faster.

That's excellent! I've never used those drilled nuts before, although I've seen photos of them on McMaster-Carr's Web site. Nord-Locks do seem nice, and I always feel like I'm using some UFO technology on #50 when I break them out.

As always, this is just my way and not exactly a given.

Understood! Thanks very much for taking the time to explain your preferences!

Nice looking timber by the way!! As a hobbyist Luthier, and wood worker, I couldn't help but notice. What tree did that once belong to?

Thanks! Those blocks are #1 Douglas Fir and were cut from a 16' 4x12, a 12' 4x12, and an 8' 2x12. I'm not sure what it means, but I'm looking at my receipt right now and the 4x12 planks are prefixed with, "FOHC," while the 2x12 says, "BTR." I don't know much about wood!

I picked these up from the finest lumber yard I've ever been to, Bruce Bauer Lumber & Supply, on July 30th, 2008. I had them cut specifically to support #50's frame on an uneven gravel surface while I renovated the front suspension, and they're holding up well!

Here's a photo of them from when they were fresh and smelly.



Frank, thanks for your generous and high quality replies!
Robroy

[fordman]

i took my nut off with a screwdriver. it alreay had a nick in it from someone else doing the same thing before. but if yours isnt messed up i would use a screwdriver on it. here is a picture of the bendix hd brakes once you get the drum off. and the diagram fo the bendix brakes. http://www.fordification.com/tech/image ... akes01.jpg dont forget to repack your wheel bearings with axle grease before yo ureinstall them.

[FreakysFords]

That's interesting! I've never heard of Perkins before. Is this the Perkins your referring to? And are engine adapter and block both in the context of these Perkins engines (not anything you'd find on a Bumpside normally)?

Yup! that is be them. I hope to have at least one in a bump in the near future.

Great. Since these are very old and crusty looking, I'll try to replace them then! These also appear to be grade 5 bolts, which surprised me a little bit. Don't these take the full shearing force of the drivetrain at the wheels?

Well sorta. The friction they hold between hub and flange should keep them from ever being in true shear. In an ideal situation (this is per book, not real world) the bolts wouldn't be touching the sides of the hole in the flange.

Do you happen to know what purpose the shoulder serves on these bolts? I was wondering about that. Also, the washer might appear to be somewhat captive on the bolt in my photo, yet it's not washered per se--it seems to be a regular (albeit unusually thick) lock-washer slipped on to the bolt.

The shoulder is harder to twist, stress and can take better shock loading than the threaded portion, but in all honesty, the shock loading part doesn't really apply as much as the rest does, since the threaded portion is still partially exposed. The other thing is that if the shoulder does contact the flange at some point, it will actually protect the exposed threads as it is a minuscule fraction larger in circumference than the threaded portion.

Would studs be beneficial in this situation because they'd make it easier to re-install the axle? Or simply because it's easier than trying to get the first couple of bolts started while holding the axle in place?

They could make it easier to install the axle, but as you'll find when you re-install yours, it's super easy to start with. The primary reason for studs is that you have three friction devices holding the fastener rather than two. In practice, studded axle flanges tend to stay put better than bolted. Again though this is something more given to extreme duty than your average driver.

Also, would Nord-Locks be more applicable to studs than bolts?

Nope, I just tend to think extra precaution which is why I go with studs in the first place (serious overkill for your situation and might not be to your liking in regards to appearance). Nords would be good either way, though again, overkill. The thick washer though is important. (Nord is the only locker I can think of with same characteristics). The washer needs to be thick to displace the load, while not being able to squish and allow the bolt to loosen.

Okay! I suppose I'll have a better mental picture of what constitutes the hub side versus the outside as soon as I get it pulled apart more deeply.

Not important, just me over talking things again. I use blue locktite on the portion that threads into the hub (just as your bolts thread in), but I don't use it on the nuts that thread onto the studs.

That's excellent! I've never used those drilled nuts before, although I've seen photos of them on McMaster-Carr's Web site. Nord-Locks do seem nice, and I always feel like I'm using some UFO technology on #50 when I break them out.

Though simple, they are a thing of wonder aren't they. Hard to believe that the simple design isn't older than it is. I'm "trying" to break with my compulsive (we're talking serious OCD to the point) need to overly secure everything. I can only think of 18 threaded fasteners on the B52 that don't use tie wire or similar (some places get a little higher tech in high heat or high friction areas, but same idea). In the aircraft field, it's second nature and hard as heck to break. How hard? I haven't touched a B52 since 1993 and the only aircraft I work on at all are for family, friends and myself.

Thanks! Those blocks are #1 Douglas Fir and were cut from a 16' 4x12, a 12' 4x12, and an 8' 2x12. I'm not sure what it means, but I'm looking at my receipt right now and the 4x12 planks are prefixed with, "FOHC," while the 2x12 says, "BTR." I don't know much about wood!

I picked these up from the finest lumber yard I've ever been to, Bruce Bauer Lumber & Supply, on July 30th, 2008. I had them cut specifically to support #50's frame on an uneven gravel surface while I renovated the front suspension, and they're holding up well!

Here's a photo of them from when they were fresh and smelly.

[ Image ]

Frank, thanks for your generous and high quality replies!
Robroy

Thank you sir for feeding my abundant curiosity.

Frank

On a side note, if you don't find your bolts, don't let that stop you. Use what you have and replace them one by one when your new ones arrive.

[robroy]

Good day Fordman!

i took my nut off with a screwdriver. it alreay had a nick in it from someone else doing the same thing before.

Oh I see--that's interesting! Although without a socket, I'm not sure how I'd torque it when putting it back together.

but if yours isnt messed up i would use a screwdriver on it.

The nuts look like they're in perfect shape, so I suppose I'll wait until I have the correct socket. Plus, with their smooth surfaces, I'm not sure how a screwdriver could be used to remove them.

Fordman, I took a closer look at IMG_7438x.JPG, and saw that notch you mentioned on my nut as well! I was negligent before to not look at it more closely before responding to your helpful remarks.

I'll give the screwdriver method a try and see what happens. At least that way I can get rolling on it today instead of having to wait until tomorrow to crack it open!

Thanks very much Fordman!
Robroy

[robroy]

Good afternoon!

Thanks to Fordman's advice regarding the bolt notch and screwdriver removal method, and thanks to GSequoia's excellent article, I've made some progress!

Here I'm turning the 2 and 9/16" nut using a chisel-edge punch and hammer in the nut's notch. In retrospect I should have used a screwdriver as Fordman suggested, because I didn't need to hit it very hard to turn it loose, and the punch cut in to the notch somewhat!



I found that in addition to Fordman's great suggestion, I needed to follow GSequoia's advice in his article by smacking the peculiar lock-washer's ears back with the punch to get the 2 and 9/16" nut fully off.



I found the peculiar lock-washer's ears difficult to see in there. When they're bent down over the contours of the huge nut, they prevent it from spinning off easily.



I was then able to remove the outer 2 and 9/16" nut (left) and the peculiar lock-washer (right).



I gave the outer 2 and 9/16" nut and the peculiar lock-washer a quick bath in brake cleaner, just to get a better look at them.



With the outer nut and lock-washer removed, the inner nut unscrewed easily. Here I've unscrewed the inner nut to the end of the threads (left), and removed it entirely (right).



Following GSequoia's article, I pulled the drum out a few inches and pushed it back in. This brought the bearing out to the edge where I could neatly pluck it out.




Then I pulled the drum completely off!



I placed the bearing, inner nut, peculiar lock-washer, and outer nut back on the spindle for safekeeping.



And here's how everything looked!




Here are close-ups of the brake shoe lining (left) and the inside of the drum (right). Perhaps I need to clean the drum before its condition can be judged?



And here are the wheel cylinder and self-adjusting areas.




Based on what y'all see in these photos, is it possible to determine whether or not these brakes are sufficiently worn out and/or crusty to justify a full rebuild? What words of wisdom do y'all have for me? (Remember that clicking on these photos will yield much larger editions, which could come in handy for visual inspection!)

Thanks very much for all the superb guidance!
Robroy

[flyboy2610]

This is just me, but whenever I have brakes apart, unless the linings are almost like new, I replace them. Just so I don't have to get in there anytime soon to do it again.

[robroy]

Good afternoon FlyBoy2610, thanks for replying!

This is just me, but whenever I have brakes apart, unless the linings are almost like new, I replace them. Just so I don't have to get in there anytime soon to do it again.

I know what you mean, and that's probably same direction I'd go in by default. The linings don't look super fresh to me, and everything looks pretty rusty and prehistoric. It hasn't been touched in 14 years so maybe it's time!

Thanks again for your excellent reply FlyBoy2610!
Robroy