Front wheel brakes/bearings 1967 GMC...

[jabborabbo]

Hello all-

I drove my truck a few days ago and noticed a smell...when I got home I saw wispy smoke coming from the left front tire well. I checked the hub temperature from the inside with a pistol grip remote temp gauge, and it show the hub at 360 degrees F. I’ve removed the wheel and brake drum - the drum came off easily and didn’t show any undo wear on the drum and the shoes have plenty of lining left, so I figured it was the wheel bearings...I removed them and they don’t appear to be bad, and I didn’t hear the typical squealing when bearings go bad...so what happened? I’m attaching a pic that includes showing the brake cylinder which appears to be somewhat cooked. How should I proceed?

P.S. The truck brakes worked fine, and I didn’t notice the truck pulling to the left during the drive home....

[gmc684x4]

How Dry was the grease packed in the bearings ?

[BigBird05]

Did you check the temp of the right front drum. I have no reference temp wise if that temp is normal or not.

[68Gold/white]

It's generally a brake hose that has collapsed. Your case was minor, fortunate the situation wasn't anything like towing or an emergency stop.
It couyld be a master cyl issue, although not nearly as likely as the hose.
IF, IF you don't know if or when the hoses were replaced, just go ahead and replace BOTH front hoses, just to be SAFE. I'd do the rear too. THe hoses are NOT expensive!!!

[jabborabbo]

Originally Posted by gmc684x4

How Dry was the grease packed in the bearings ?

Not dry at all.

[jabborabbo]

Originally Posted by BigBird05

Did you check the temp of the right front drum. I have no reference temp wise if that temp is normal or not.

Right drum temp was around 120 F.

[jabborabbo]

Originally Posted by 68Gold/white

It's generally a brake hose that has collapsed. Your case was minor, fortunate the situation wasn't anything like towing or an emergency stop.
It couyld be a master cyl issue, although not nearly as likely as the hose.
IF, IF you don't know if or when the hoses were replaced, just go ahead and replace BOTH front hoses, just to be SAFE. I'd do the rear too. THe hoses are NOT expensive!!!

I don’t know if the hoses have ever been replaced...sounds like a good place to start!

[Steeveedee]

Originally Posted by 68Gold/white

It's generally a brake hose that has collapsed. Your case was minor, fortunate the situation wasn't anything like towing or an emergency stop.
It couyld be a master cyl issue, although not nearly as likely as the hose.
IF, IF you don't know if or when the hoses were replaced, just go ahead and replace BOTH front hoses, just to be SAFE. I'd do the rear too. THe hoses are NOT expensive!!!

Yup, nailed it, I bet. I'd do all three as well.

[jabborabbo]

Ok, my ignorance is confusing me...if the hose collapses then the shoes will bear against the drum, right? If that happens, then shouldn’t the truck noticeably pull to the left? I’m just trying to educate myself before I start putting money and effort in this thing....

And BTW, thanks to all that have replied!

[68Gold/white]

Originally Posted by jabborabbo

Ok, my ignorance is confusing me...if the hose collapses then the shoes will bear against the drum, right? If that happens, then shouldn’t the truck noticeably pull to the left? I’m just trying to educate myself before I start putting money and effort in this thing....

And BTW, thanks to all that have replied!

The brake hose problem can be subtle, like yours. Yours got a little restriction, and held the brake shoes against the drums a little more than normal. You got a warning sign, and thankfully noticed it.

Sometimes the hose will collapse in a huge way,and lock the shoes against the drums solid, leaving you beside the road, trying to diagnose it on the road This situation DOES pull to one side, the side of the road that you are stranded on!!!

I couldn't blame you if you wanted to try to diagnose it for a "for sure" fix. Put it together, go out and get the brake system warmed up from some normal driving. Then do a few minor panic stops. See how it stops after that. Be DARN careful!!!

I work on vehicles for a living. I claim to be an expert at nothing!!! Try to be helpful here. Many older vehicles had certain "chains of events" that led to a usually fairly accurate diagnosis of a mechanical problem. Yours is one of the "usually" spot on, repairs. I work on school buses. a bunch of the stuff on them is fairly easy....until a computer is needed. screw that!!! I've been working on a 94 ford van E150. Can't get it to run, have thrown a bunch of parts at it. Have run diagnostic procedures, one after, another. Towed it to a local shop, here, have at it!!! Did I mention its a CRAPPY FORD???

[mr48chev]

I'd say that the guys are correct in saying that the left side is either dragging a bit compared to the right.

Make sure the adjusters on both wheels are free and working the way they should and the brakes on both wheels are adjusted correctly. It doesn't hurt to check the back at the same time too.

It might be that the brakes on that wheel are working harder than the other wheel making up for it not working as well. Simply meaning that you need to check the whole system and make sure that you figure out the issue.

I did brake and front end work every day for several years and quite often the problem isn't on the side you think it is when it comes to brakes.

if the hoses look at all suspect I'd change them though and probably change the one at the rear at the same time. They aren't very expensive and do get tired and break down over time.

[gmc684x4]

Yes changing brake hoses is something most guys balk at doing
They are cheap the can collapse inside or have a hole that lets go on a friday evening rush hour and boom no brakes in high traffic

[jabborabbo]

Ok, I’m educated! Again, thanks for all the replies!

Now, can anyone give me a good source for the front and rear brake lines? I’m understandably reluctant buying them from local box store sources....

Thanks again!