Slammed on brakes, rear spun around.

[emil77]

Hi guys,

So educate me a little bit on the correct driving practice of our trucks. Today, the light I was approaching turned red, I couldn't make it, so I slammed on the brakes, the whole rear of the truck spun around and I did a 180! So, what did I do wrong? What is the correct way to stop in the event of an emergency?

[NW_Ryker]

My blazer pulls hard to the left when I hit the brakes hard. That's pretty crazy that it spun like that. Have you had your suspension/brakes checked lately?

[Andy4639]

These trucks are very light on the rear end when it comes to quick stops. You didn't do anything wrong it's just the nature of the beast!Have the wheel cyclinders checked and have the whole brake system tested to make sure you don't have any issues.

[Sicklajoie]

^^^True.
When the ass end is light you're going to lock up the rears.

[71swb4x4]

"Slamming" on the brakes is a no-no on non-ABS vehicles, you need to pump the brakes in low-traction conditions or use steady pressure in good traction situations.
If you spun around you may have one caliper grabbing before the other. Does it pull when you push the pedal hard? If so start with the easy stuff, bleed the system first. Then check pads/rotors/calipers and shoes/wheel cylinders/shoes in the rear.

[sjarrett71]

Your rear wheels will lock up first due to the lightness of the rear of a truck and weight transfer. Your truck spun around because the wheels that locked up lost traction with the roadway and were actually travelling faster than the front. Naturally the faster moving end wants to be in front, thus the spinning.

[cdowns]

you can stop faster and safer by learning how to pump the brakes rather than panicing and slamming them and keeping them locked

[Longhorn Man]

this is funny, 2 weeks ago when someone had pretty much the same question, the majority said he had a brake problem... now the majority is saying that's how it is.

Like i said a couple weeks ago... that's how it is.

[swamp rat]

Originally Posted by emil77

Hi guys,

The light I was approaching turned red, I couldn't make it, so I slammed on the brakes,

So, what did I do wrong?

I think what you did wrong was not slowing down to a yellow light until the last second when you realised you would run a red light..

[71gmcburb]

you can try putting waight in the bed see if thats the issue but I don't think it is your front should lock first even tho the rear is light and empty since it does 60% of the braking. You should have power disk brakes up there and they grab much better then drums. I've been driving classic iron for over 20 yrs Ford Chevy GMC and dodge, vans and trucks and I've NEVER had one spin on me. check your proportioning valve under the master and make sure it is flowing properly and if thats working check your front calipers and hoses then bleed the entire system You probably have a little air in the front lines

[scrapmetalart]

Its an old truck. Slow down & pay attention. Give your self more room.

[swamp rat]

Locked up rears even in a car (heavyer rear) will slide faster than the front under braking causing a spin.

[BAGNDRAGIT]

Originally Posted by scrapmetalart

Its an old truck. Slow down & pay attention. Give your self more room.

[emil77]

Thanks for the feedback.

[vectorit]

Driving my 68 burb on the highways and byways, I am reminded as to how fast people drive. Now a days cars/trucks are so insulated from speed, and the newer vehicles are just that much more engineered people take it all for granted. (Thus taking a lot more risks, speeding, hard braking, and tail gating).

I find myself in the "slow lane" doing 65 mph, and slowing down even more to give a ten car length between me and the car ahead of me. Maybe it's just me, but my burb is on four wheel drums. Though my brakes are all gone through and are just as they should be for 1968 technology, they won't stop a K20 Suburban doing 45 mph like a 2011 Suburban can.

At upcoming intersections while I am doing the speed limit, I tend to slow down to anticipate the yellow light so that I can come to a gentle stop. Most people including myself while driving their couple year old car/truck, tend to press the gas peddle when they anticipate a yellow light.

Getting behind the wheel of a 40+ year old car/truck, you need to change your driving habits. Since that old vehicle isn't your Honda commuter car any more.

I'm happy to have read your post with out it saying your truck took out a half dozen cars while doing it's pirouette dressed in tire smoke, and that you drove away with nothing but some white knuckles and a higher blood pressure.

Drive safe.

[hdflstf]

Had a touch of the same today. In the rain.. had to gat over a lane. Only space was behind a bus. No sooner than I change lanes, some idiot cuts the bus off so he hits the brakes hard. Panic stop, rears lock almost immediately (go figure..). Rear slides a bit to the right due to the crown on the road. Off the brakes and back on them, now all 4 wheels are under control.

Just be careful and be aware that these trucks don't stop like the newer stuff out there.

[Andy4639]

There is no substitute for driving correctley in any given sitchuation, as in driving to fast for conditions are tailgating, speeding it's all there. These trucks are know for being light on the rear end no matter what kind of driver you are and when you realize that then you know how to drive in the perticular sitchuation.
Just because your vehicle says it will do 100MPH doesn't mean the driver can!

[5150.4.67]

I like adjustable prop valves. Adjust the rear so it doesn't lock up on panic stops. Up to 80% of breaking power in a hard stop is up front.....
My dad had a 68 Freightliner with no front brakes....... which was common back then. Unloaded, that thing would make your cheeks pucker if you had to stop quickly.

[Spoof]

I've never had my truck spin around like that during hard braking. I've had it do lots of shimmying and sliding etc. I say check the brakes.

[treveiger]

You did nothing wrong except for when it happens next time make it look like you did it on purpose and when the light turns green just get a big smile then put it in reverse and go. Thats how i do it when ive lost control, its funny people think im a amazing driver but in reality im just a dumbass that knows how to take control of the vehical back but i do screw around a lot and pratice losing control and gaining it back just so i know how to get it back so maybe thats why i havent crashed yet.
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[71veronica]

Emil77 I kinda did the same thing doin 80mph. Traffic all stopped at once. but I did it on the freeway I spun twice though . The motor died when i finally stop.lucky I didnt hit anyone . Let's just say I needed to change my pants after .
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[special-K]

I've been driving these trucks since they were new and never experienced this problem with correctly working brakes. Panic stops will bring out the flaws in any brake system in any vehicle. Engineers can only do so much and the rest id up to us with our driving habits and skills. Once the rear starts going to one side you should counter steer and let off the brake,even for a split second,then back on the brake. The truck will right itself. If you had a lot of speed you may need to repeat this sequence several times.

[68Stepbed]

I agree with what most are saying, especially giving yourself more time and room, and just simply driving more carefully.

I will say, however, that you may need to have your brakes checked as well as you axles seals. I once had a 90 Chevy LB truck. The rears would lock up very easy on it. It was fun for a while because I lived in a rural area of NE AR. I learned to do alot of 180's and powerslides on wide gravel roads. Eventually, though, I had it checked. The axle seals were leaking. Somehow, the gear oil actually makes the brakes grab harder. Once I had it fixed, it would barley lock up unless it was just pure hard braking.

Also, make sure you have a good brand of brake shoe. I had brand new pads and shoes put on my ElCamino years ago. I bought the cheap Advanced Auto Brand at the time. Both front and rears would lock up in any loose traction situation. I rearended someone at a stoplight once(low speed, no damage) because it was wet, but later wrecked the car on a curvy road when I didn't see a sharp left turn at the bottom of a hill. I wasn't going fast, but when I saw the curve, I touched the brakes and they immediately locked up, again, because it was wet.

Make sure you buy good pads and shoes from a well known company like Napa or Federated(Raybestos).

[oldgold70c10]

You should definitely check your brakes, and tire pressures/wear. Your truck should have braked nice & straight.

[alsriv2]

I came accross these two web articles on this website and have saved them for my reference in the future. There is excellent information in both of the articles, some of which might be useful for your situation.

But as others have said, there is no better fix than to drive safely and defensively. 40 Year old technology was as good as it gets - for situations and driving habits from 40 years ago.

Here are the links to the articles:

http://www.thebrakeman.com/valvetechi
http://www.thebrakeman.com/valvetechii

AL
'69 GMC 2500
'69 Chevy C10 396