55.2-59 Issues with rear brakes

[jeffs56]

Hey guys hope you guys can help. I’m working on my 56 Chevy truck and having issues with squeaking/squealing/grinding sounds when I press the breaks. I took it to the shop today and he said he thinks the drums aren’t true. I have a ford 9” that has been narrowed with brand new axles with 5x4.75 bolt pattern. The guy showed me the inside of the drum and it looks like it is rubbing. The guy that installed all this had to grind some spots on the metal part of the brake shoes which I thought was odd. The guy at the shop is saying maybe he didn’t cut the axles to the correct size causing it to stick out farther and having the brakes hit the inside of the drum. What do you guys think. I’m hoping it’s just a not true drum and be good.
Also would going to disc brakes fix these problems? Thank you

[Tempest67]

well, you raise a lot of questions, and I will try to help,

1. where are the brake shoes rubbing on the drum? ..and did grinding the shoes help? I think grinding the metal on the brake shoes is a very bad idea

2. custom axles - if they are too short, I would think the drums would touch the backing plates before they touch the shoes? and there would be a grinding sound whenever the wheel turns, not just braking.

- if they were too long, the shoes would show between the backing plate and drum. (be visible) and the shoes would not be making full contact with the drum, but there would be no grinding

3. not true? - if the drums were 'out of round' they would create a pulsation when you apply them, but not necessarily a grinding sound.

would disc brakes solve the problem? if the drums are grinding, I would say Yes, but that would be expensive, and I would want to know where the grinding sound is coming from first.


Hopefully this may help, can you post some pics?

[leegreen]

My initial reaction is that you need to take it to a more knowledgeable shop. Rear drums are not that complex and any shop that can't figure out why yours are grinding is not one I'd go back to.

I agree with tempest67's comments.
Pictures would help for sure.

So would knowing how the axle was narrowed: still ford backing plates & bearings? is it still a ford drum redrilled or is there a chev drum on a ford backing plate now? brake shoes & mechanism ford or chevy? Grinding on the shoes is weird and I bet there is some mixing and matching going on.

Converting to rear disk on it's own may not fix the issue if the axles are the wrong length, bent or mismatched with the ford bearing retainers

[jeffs56]

It definitely pulsates at really slow speeds you can fell it. He showed me where it was rubbing on half of the drum, which is why he said the drums aren’t true. It looks like the shoes were hitting the inside lip on the drum. I’ll see if I can pull it back apart and take some pics

[jeffs56]

It’s all Ford parts except the drums are aftermarket with the Chevy bolt pattern

[leegreen]

> He showed me where it was rubbing on half of the drum<
Shoes rubbing on the inside corner of drum or the friction surface?

> pulsates at really slow speeds you can fell it.<
1 check for runout on the axles when you have it apart

2 check the drum fits snug on the hub of the axle, no slop

3 check the drum friction surface runout against that centre hub of the drum.

back in the day when I did brakes for a living and drums were common, jobber market drums were sold rough finished - the inside was machined, but only a rough pass, not to spec. We always re-machined, then arced the shoes to match the drum so the vehicle would leave the shop with perfect shoe contact. it was not uncommon to get drums that were eccentric and the occasional one rejected as so badly out of round it would be oversized if we machined it true.
Buying drums these days they are commonly finish machined and shoes are over-arced so they will break in without destroying themselves. (Always scrub the shoe inside the drum before install and ensure you don't have contact only at leading and trailing edges - that tends to grab hard, burn up the friction surface before it wears in and in some cases tear the friction lining right off the shoe)
so my point is: the aftermarket drums ..... how were they prepared, were they checked?

[jeffs56]

Aftermarket drums were checked and he noticed having issues with rubbing and the squeaking. So he took the drums in and had them true. But the shop I took it to yesterday showed me that they weren’t round. Should I try to send these drums in again and try to have them trued up. The original guy working on it said he can send me a new set of drums. Not sure what route to go

[leegreen]

if the drums are not round they need to be fixed / replaced, so if guy1 is offering a free set that seems like a step in the right direction. But I'm not understanding the bit about guy1 having to grind metal parts on the shoes yet, as you say that is weird so I'd be reluctant to let him off whatever hook you have him on for the price of 2 drums


How did guy2 show they were not round?
Did he show if/where they were rubbing? Rubbing as in metal on metal?

here are 3 common rubbing points for reference:

[jeffs56]

Definitely rubbing on number 1 and 2 on the drum and showed me wear on number 3. He grinder the outside of the shoes because it was hitting the number 1 on the drum

[leegreen]

Ok

3 is hitting backing plate, either wrong drum or axles too short

edge of shoe is hitting inside of drum at 1, and shoe was ground at 1. either shoes too wide or axles too short

on the inside of the drum at 1 is it rubbing all around or just at places?
Just in places then the casting may be imperfect and need truing up perpendicular to the friction surface.

is point 2 I labeled on the shoe rubbing point 2 on drum??
that would be a very worn out shoe or a shoe badly matched to the application and probably the adjuster cranked out to compensate. Does the shoe friction surface show wear over the entire shoe?

What is the evidence the drum is out of round?

[jeffs56]

If I remember correctly he showed me where number 3 was rubbing it was darker
Number 2, I think he showed me number 2 was rubbing because it get hot. I’m going to call him again and write it down this time lol. So if it’s too short of an axle then he needs to replace the axles again right? Or how would you fix this?

[leegreen]

#3, if it was rubbing I'd expect a bright spot unless there was so much friction it heated up and turned the metal at 3 blue/purple?

#2 should get hot, but not so hot the friction surface of the drum starts to get blue or the friction surface of the shoe changes color, looks burnt or cracked (if that is the case the shoes are junk)

the brake pulsing at low speed is the evidence drums or axles are not round and true, is there any visible evidence to show any rotational difference, like rubbing that is only on part of drum circumference?

if the issue is axles are only slightly too short a small machined true on both sides spacer between drum and axle may be sufficient. it wont help if the axles are out of true. Don't use 5 flat washers except as a test, 100% chance you will have a vibration.

Tip: later year 3rd gen camaros had a 1/16 rear wheel spacer from factory for some reason. it will fit between drum and axle. (and it will let you run 3rd gen camaro drums on a 2nd gen s10 - barely and with some rubbing at 3 in hard corners - while you wait for the new s10 drums to be delivered)

It is sounding like guy1 had some tolerance issues he tried to fix with the grinder, if he was paid to deliver a fully working shortened rear end he failed

[leegreen]

was the axle housing shortened by someone that knew their stuff and made sure it was straightened again after they welded it back together and welded spring pads on?

the backing plates may not be square to the axle tubes depending how they shortened it
the axles may be binding if it is warped bad enough

[mr48chev]

Leegreen did one great job of figuring out what might be the issues.

The lip of the drum that is touching the backing plate is easy to trim down in a disk/drum brake lathe if you know what you are doing. If that was the only issue and you had plenty of room for the drum and shoe to clear on the outer edge that is what I would suggest.

Not knowing what width of shoes you have that issue might be solved by going to the next width down of that size of shoes.

Looking up a 64 Galaxie 500 with a 289 it shows 11 x 2.57 # 264 shoes

Then looking up a 68 F100 it shows 11 x2.31 rear shoes # 263

Looking up the 74 F100 rear I have out here it says that it either can have 11x2 or 11 x .231 shoes on the rear.

Ford doesn't make it easy.

After dinking around with looking for other fixes what I am thinking is the solution is to check the width of the shoes, go down one width Or enough width) to get the space on the The inner corner (#1 that Lee marked) and cut the lip of the drum down to clear the backing plate. That probably means taking .050 or so off that edge and the brake guy should have already done that. It is a simple process after you set the brake lathe up to do it to take a few thousandths off at a time.

You might want to check what width of rear brake shoes match the front brakes you have and match the rear brake shoe width with that. Too much brake on the back of a Chevy pickup can cause the brakes to lock up on the rear before the fronts do and send you into a spin. The drum doesn't care how wide the shoe is as far as how much drum surface it contacts it just wears a tad different. That may save adding and adjustable proportioning valve on the rear brake line to dial the rear brakes in too.

That may cost you the price of another set of shoes but is a lot less expensive than other options . A lot faster time wise too.

[jeffs56]

All he told me was the shoes are 11x 2 inches. He’s sending me a new set of drums. So I’m hoping that works. If not then I guess it’s a whole different animal. The original guy doing the work said he will cover everything and fix it, that’s not the issue. I was just trying to see if it was something I can fix myself easy cuz he’s two hours away and would have to be trailered there and left. Once the shop backed off the brakes I don’t recall it squeaking anymore. Would that adjustment fix the issue?

[mr48chev]

A lot of things can make brakes squeak.

One is the really"good" metallic lining that stops best, Years ago when I was doing a lot of brake jobs in a Firestone store in Texas the shoes I had the most noise complaints from were the top of the line metallic and probably harder shoes. On the other hand, the least number of complaints we had were some 3.95 an axle shoes whe got from a discount parts house up the street that didn't even have them in boxes. The had pairs of shoes wired together in big boxes that you dug the shoes out of. We were doing 12.95 an axle brake relines with those good for 10,000 miles.

2 inch shoes being too wide for the drums makes me wanted what the drums started out being for. If the drums were redrilled from the Ford pattern I'd bet that is what they used, early Bronco / F100 drums

Rear shoes for a 70 Bronco are #283 that are 11 x 1.75 They fit the early Broncos and F 100 trucks. https://www.oreillyauto.com/detail/c...d-bronco?pos=2

The Bronco rear brake drum isn't all that wide as far as friction surface goes https://www.oreillyauto.com/detail/c...d-bronco?pos=1

[jeffs56]

They are drums with 5x4.75 from a company online not sure where he ordered them. They are brand new not the redrilled Ford drums

[leegreen]

the concern with going to narrower shoes is the offset of the wheel cylinder, the length of the anchor points and the length of the hold down pins and springs.

You don't want the shoe to sit crooked relative to the backing plate as may happen if the anchor points hold it away from the backing plate,
you don't want the wheel cylinder to bind as the shoe is no longer centered and you don't want the hold downs too long so the shoes rattle.

you can go narrower but it is not just a matter of slapping narrow shoes on, you need to confirm the setup will work properly or replace some parts with those designed for the brake version with narrower shoes.


an aside:
48chev mentioned reducing rear brakes power as one possibly desirable outcome of narrower shoes. Another way to do that is to put on 4 of the front shoes with less lining material or simply sand away some percentage of the surface area of the lining on your existing shoes.
-taking precautions with the dust!-

[jeffs56]

I’m going to try to have another guy I know look at it that builds hot rods. If not the original guy said he will take care of it all for nothing. Just was hoping I could fix it quick so I can keep driving my truck. Would a disc brake conversion kit fix all this. If so which one would you guys recommend?

[mr48chev]

Well you can lead them to water but you dang well can't help them drink.

I don't know how I could have made it any plainer, you need to do two things for it to work, Take the 2 inch shoes off and put 1-3/4 shoes on. That is a 15 minute a wheel task.

When people mix and match pieces and buy this here and that there they don't always get the right mix of parts. Then have someone trim enough off the lip of each drum so that they don't rub the backing plates. That is a pretty common thing when mixing a batch of parts together that may or may not have been designed to work with each other. That is a simple ten minute task per drum if that for someone with a brake lathe preferrable one that does drums and disks. You have to be able to think outside the box.

There is no reason to spend a bunch of money having disk brakes at this time because this didn't work.

It could be that the drums were a bit off but if the new drums don't fix it change the shoes and trim the lip on the drum and go drive the truck.

[jeffs56]

Sorry I don’t know as much as you do. I’m trying to figure it out without taking it 2 hours on a trailer to the original guy. Nothing was pieced together. It was a complete kit from backing plate to the hub.

[dsraven]

if you take it to a shop, or try it yourself, get it on stands and remove the rear wheels and brake drums. use a straight edge across the axle flange where the drum fits on. a piece of angle iron would work well because you can drill holes to bolt it down to the flange or you can use vice grips or a clamp to keep it in place. when you have the straight edge on the flange, so it sticks out the sides parallel to the flange, then use a combination square against the straight edge to determine the dimension from the flange to the near and far edge of the brake shoes. next use that dimension on the brake drum. place the drum upside down like a tea cup and place the straight edge across the top. now take the combination square and measure from there to the flange mounting surface. compare results

[mr48chev]

If the drum he is sending doesn't fix it, Wildwood sells a .090 (Speedways says .094) steel wheel shim/spacer that is normally used to protect the alloy Wildwood hubs from steel wheels but would move the drum out .090 from the backing plate and outer edge of the shoe. https://www.speedwaymotors.com/Wilwo...BoCi5cQAvD_BwE

[hogfarm]

I just had a similar situation. I shortened a ford 9",3" on each side. with drum brakes.I sent my housing and axles to Dutchman's axle to have the work done. I had no problems at all. I'm thinking your problem is in the length of the axles

[jeffs56]

We looked at it again today and the drums have some slop in them. So I think the drums need to be replaced. It has speedway motors axles, but a different brake kit and drum. We measured it and it’s off by a little too much slop. The drum itself isn’t touching the backing plate. The only thing that’s rubbing is the shoes on the inside lip of the drum. That problem should be fixed now. Had to grind the metal around it just a little bit. Squeaking is gone