Front Brake Squeal

[Lieutenant Dan]

Ok so I just got done rebuilding front axle and went over all the brakes. I rebuilt the wheel cylinders and all my shoes I matched and are like brand new. But I have a horrible squeal in the front now under hard braking ever since a guy came up behind me fast then cut me off and then brake checked me. I had to slam on the brakes like 40 miles after rebuild and now the squeal. They only do it at slower speeds and under moderate to hard braking.

Anyone have any ideas what it is and why? Possibly how I can fix it? I'm at a loss right now and it drives me nuts to have a good looking truck that squeals when I stop. Nothing like that then people hear it and think man what a POS that is......

Please Help..... There is nothing in the tm about squeaky brakes...... I checked

 

[porkysplace]

Were the drums turned?

 

[Lieutenant Dan]

No they looked fine and measured even

 

[porkysplace]

Sounds like they are glazed.

 

[Lieutenant Dan]

I guess I'll have to pull them back apart and we what's going on. Will any heavy truck shop be able to turn them?

 

[gimpyrobb]

All squeal? I'd jack each wheel up and find which it is before I pulled them ALL.

 

[Lieutenant Dan]

No gimp it's just the fronts.

 

[Lieutenant Dan]

The right front first then if I brake harder the left front the rears don't do it.

 

[Lieutenant Dan]

I thought maybe it would go away after a bit but I have probably 100 miles on it now since I redid them and it's still doing it if not worse

 

[gimpyrobb]

Maybe something is out of adjustment, I'd also scuff the drums up while they are off. Inspect pads for wear marks, etc.(I'm sure you know this.)

 

[wilfreeman]

Will any heavy truck shop be able to turn them?

I'd like to know this also. Who turns these big ol hunks of iron? I am getting ready to do the brakes and seals on my spare axle before I put it on the truck and want to get the drums turned while I have them torn apart.

 

[rustystud]

Yes the brakes have become glazed (drums and shoes) . One way to fix it (and yes I know it is not factory!) is to throw some sand into the drum and hit the pedal hard. The sand will scuff up the shoes taking away the glaze. The only other way (which is factory) is to take the drums have them turned (all of them) and either install new shoes or scuff up the shoes with a sanding pad. If you do not break-in the shoes properly you will get a glaze on them and they will squeal like a pig
After completing a brake job you will need to make several stops at 20 mph (10 - 12) . Then increase speed to 40 mph and make several more (10 -12) complete stops . The stops must be slow and gentle, NO sudden hard stops. After the brakes are broke-in they should function just fine. One thing that old timers would know about is that all the older cars (70 and older) used to have the shoes turned to the drums. Our busses do to this day. You have almost complete broke-in brakes from the start. The only problem is you use up about 30% of the shoe lining doing this. We do this because of the safety factor (public transit) .

 

[rustystud]

I'd like to know this also. Who turns these big ol hunks of iron? I am getting ready to do the brakes and seals on my spare axle before I put it on the truck and want to get the drums turned while I have them torn apart.

Yes, any truck shop will be able to turn your drums. There are really quite small compared to a modern over the road truck or buss. Our drums weigh-in at 200lbs each . We use a hoist to install them. The complete wheel assembly weighs-in at 900lbs . I actually herniated my L4-L5 disc moving a drum off the hub.

 

[Lieutenant Dan]

Yeah i know they aren't light. ... .I was just wondering since it have the bearing in it if they could be turned..... I think i might take the drums off my spare axle have those turned and then get new pads and swap them out. Then I'll have those drums to do the same thing if the rear starts acting up.

 

[RAYZER]

I had a bad squeal from the front brakes on my deuce, come to find out that most of the rivets holding the lining to the shoes were gone or loose!
I Put on a new pair of shoes to fix it.

 

[Lieutenant Dan]

All my rivets were good like I said the shoes were almost new.....

 

[rosco]

The last thing I would do, is turn those drums. Un-turned drums will have to seat in. Get them hot, like on a long hill, and your noise will go away. If you feel that you have to do something, use the "sand trick" above (like with plaster sand - something fine).

 

[RAYZER]

All my rivets were good like I said the shoes were almost new.....

Ya, mine looked new as well.
Hope you solve the issue, squealing brakes are embarrassing!

 

[Lieutenant Dan]

Yeah it is super embarrassing.

Rosco how are you doing the sand trick? I've never heard of that before. I'm going to try a long hill today hopefully and see what that does.

 

[glassk]

All my rivets were good like I said the shoes were almost new.....

Brake squeal, whether disc or drum, is generally a matter of vibration. That is, the friction pad or shoe, or in a few cases the disc itself, oscillates -- just a fancy way to say vibrates -- at a very high frequency, creating the squealing sound.

Could be the springs if they are not changed with shoes, just an Idea,...