Locked Up and Sideways

[bloody hammer]

Since getting my '62 Stepside running again I've only driven it on short trips around the neighborhood. Today was the first time for a longer trip across town to visit a friend. I get maybe 2 miles from my house when this dimwit in a van decides to not only jump into my lane right ahead of me but then he immediately slams on his brakes so he can wait to continue crossing lanes. Of course I had to slam on mine too and I was quickly reminded of not having anti-lock brakes.. haha.

I fishtailed so badly I had to let off the brakes even though the numbskull was still in front of me. So, it was slam, lock, fishtail, let off brakes... then slam, lock, fishtail all over again. Luckily he moved to the far left lane. I barely missed him.

I realize I'm not used to manual brakes but I can't help but think they should not have locked up that quickly. I think I need to do some brake work.

[VonDog]

Wish my brakes worked that good!!! Need drums something fierce. Glad to hear you didn't ball up your ride or give him an enema!!! Lol

[KroAutomotiveInc]

nah that's what they do in these trucks atleast mine act the same lol, you did the right thing ive had 4 incidents like this. one in my 2wd at 45 and 3 in my 4x4 one of them being at 75 mph lets just say i needed a new pair of shorts after that one... although bad adjustment can cause you to fish tail worse i know in my 4x4 that's the problem the passenger side is locking before the driver.

[slepysal]

Wow. I took my truck to work today the guy in the slow lane decided that his text message was more important then driving safe. He drifts into my lane ,and I had to slam on the brakes just missed him. Then he looks at me like I did something wrong!
I guess he realized by the "mad dog" look I gave him he was in the wrong. Close calls like that remind me that I really have to make time to install my disc brakes.
Glad you didn't squash the idiot.

[66Submarine]

Is it pulling hard left or right, or just locking up the rear? Either way, it has nothing to do with the lack of a power booster; that would just lessen the pedal effort needed to do so.

The drum size is critical for good braking performance without pulling to one side. When you turn the drum out and increase it's diameter you reduce shoe contact area and make the brakes less effective for that wheel as a result.

[bloody hammer]

It's definitely pulling to the right. I was already aware of that just cruising around the block these last few weeks but it was subtle enough that it hadn't really bothered me much. Not until yesterday when I had to jam on the brakes real quick. What surprised me was how quickly I started sliding. It was pretty instant and I barely kept it under control.

Pucker-factor 10.

[markeb01]

That's a pretty common characteristic of these trucks. There just isn't any weight over the rear axle to hold it on the ground under severe braking. I've seen a few do a 180 on the freeway when traffic in front stopped, and the rear end didn't. Pulling to the right is a different problem. Fishtailing under extreme braking will always be there unless a lot of weight is added to the bed.

Mine stops straight - now, because it has a bed cover, plywood & aluminum bed floor, spare tire, tools, a shade tent, chairs, and about 300 pounds of fuel/tank behind the rear axle. Not so good for gas mileage, but it sure inspires confidence in braking.

[TJ's Chevy]

Here where I live we have tons of numskulls like that. lol. I had some idiot almost run me over when I was riding my bike cause he wasn't watching where the heck he was going...I didn't know you could lock the tires with manual brakes...musta been pushing hard! lol! Glad you an the truck are ok!

[KroAutomotiveInc]

give it a try tj if your expecting it, it can be quit fun

[66Submarine]

Yeah, you can lock tires all day long with manual drums in good shape.

'65 Chevy C-30 brake check (four wheel manual...

[TopFuel1966]

I've had mine perpendicular to the curb while taking evasive action with disc brakes on all four corners. I'm going to try experimenting with an adjustable proportioning valve.

[gimmy 64]

this is the argument some have between disc and drum brakes.some say i have drum brakes and they work fine. thats if you don't drive freeways and don't have idiots pull in front of you.i live in califoria and where we live you nee to drive on the freeway to get to the next town 5 miles away. disc brakes are the only way to go in my opinion. .

[KroAutomotiveInc]

i agree with you gimmy i was always one of those guys who never had a problem with my drum breaks until my commute turn into 17 miles of freeway each way even paying close attention to traffic i would still end up locking them up sideways ****ting my self... not to monition all the dirty looks you get from the people around you haha...

[66Submarine]

Disk brakes do resist fade better than drums, but pulling hard to one side isn't just something drum brakes do; you have a larger diameter drum or greasy shoes on one side (or some other similar issue).

With drum brakes, turning (or wear) increases the diameter and reduces contact and braking for that wheel; the truck will then pull to one side as a result.

With disk brakes, rotor wear/turning just decreases the thickness of the flat sides of the rotor, so the contact area is still the same; that's why they don't have the tendency to pull to one side that drum brakes do.

Drum brakes are also "self-energizing", which accentuates it.

If your brakes pull hard to one side you need to fix them.

[jbgroby]

Seat need cleaning?

[bloody hammer]

Originally Posted by jbgroby

Seat need cleaning?

Nope... got lucky this time!

[LostMy65]

I don't think disc brakes would have changed the fishtail of the back end. His backs locked up and the back started to slide around. Discs aren't going to change that.
However, the front pulling to one side would be less likely with discs, but so would properly adjusted drums.

[LostMy65]

Originally Posted by markeb01

That's a pretty common characteristic of these trucks. There just isn't any weight over the rear axle to hold it on the ground under severe braking. I've seen a few do a 180 on the freeway when traffic in front stopped, and the rear end didn't. Pulling to the right is a different problem. Fishtailing under extreme braking will always be there unless a lot of weight is added to the bed.

Mine stops straight - now, because it has a bed cover, plywood & aluminum bed floor, spare tire, tools, a shade tent, chairs, and about 300 pounds of fuel/tank behind the rear axle. Not so good for gas mileage, but it sure inspires confidence in braking.

This thread got me to go back and do some googling on a topic I had already figured on my own. Brakes locking on the rear and the rear sliding around is a thing that happens with our light rear trucks whether we have discs or drums. Truck Guys with discs will often install an adjustable proportioning valve to fine tune their braking for when they are loaded or unloaded.
Well I decided to Google to find if any were using an adjustable proportioning valve on a drum/drum system, and I found where guys have done it with even cars. They adjust it until they get it just where the backs stop locking up.
They talk about how they have straighter more controllable stops.
It makes sense to me.

[Mackie]

I had a fishtailing incident driving my `63 home the day I bought it. The dope in front of me decided to slam on the brakes to let a car in from an on ramp.

A Dodge D-50 (forgive me) I had years ago had a switch/valve mounted on the rear axle that changed the braking bias when the load compressed the rear suspension.

[PGSigns]

I have power brakes and 4 wheel drums on my 66 and one of these in the line to the rear. http://www.jegs.com/i/JEGS/555/63020...FSdp7AodcFMAdw We did this all the time on the drag cars to fine tune the bias but put it in the line to the front. Also I have worked the adjustment a couple of times on the front to even them up when on the brakes hard. Seems to stop pretty good when on them hard with no bad habits.
Jimmy

[JGross]

Originally Posted by PGSigns

I have power brakes and 4 wheel drums on my 66 and one of these in the line to the rear. http://www.jegs.com/i/JEGS/555/63020...FSdp7AodcFMAdw We did this all the time on the drag cars to fine tune the bias but put it in the line to the front. Also I have worked the adjustment a couple of times on the front to even them up when on the brakes hard. Seems to stop pretty good when on them hard with no bad habits.
Jimmy

I did the same on my 65, I have power disc up front and drums in the back. After doing a 180 during a hard brake I installed the valve in the line to the rear brakes and it made a big difference. I can still lock up the rear but I really have to stand on the brakes to make it happen.

[MikeN]

Welcome to the wonderful world of drum brakes!!!

It's not only a front vs rear problem. If the shoes aren't adjusted perfectly, the right front can grab harder than the left front, or vice-versa. Once you've driven a modern vehicle, these old drum brake vehicles are an adventure. i don't drive my truck the same way I drive modern vehicles. I never get close behind anyone, and I'm a lot more careful and watchful of other vehicles. My drum brakes function normally...the technology is just not up to modern standards.

[66Submarine]

Originally Posted by MikeN

Welcome to the wonderful world of drum brakes!!!

It's not only a front vs rear problem. If the shoes aren't adjusted perfectly, the right front can grab harder than the left front, or vice-versa. Once you've driven a modern vehicle, these old drum brake vehicles are an adventure. i don't drive my truck the same way I drive modern vehicles. I never get close behind anyone, and I'm a lot more careful and watchful of other vehicles. My drum brakes function normally...the technology is just not up to modern standards.

I disagree; pulling hard to one side is certainly a problem (I explained why in a previous post).

It's a hydraulic system; a loosely adjusted wheel just means you have to displace more fluid before the shoes all make contact and you start building pressure.

My trucks with good shoes and drums stop well and don't pull to one side.

I'm actually planning to do some 60-0 tests one of these days...

[LostMy65]

Originally Posted by 66Submarine

I disagree; pulling hard to one side is certainly a problem (I explained why in a previous post).

It's a hydraulic system; a loosely adjusted wheel just means you have to displace more fluid before the shoes all make contact and you start building pressure.

My trucks with good shoes and drums stop well and don't pull to one side.

Exactly.

[61_FL_Apache]

Good wide tread on the ground helps a lot! I have had some near misses between old skinny tires and my new wider tires.. It made a world of difference.