I need some help on this one. I have a 98 F150 4x4 supercab, with 99.5K on it. I have noticed that the truck pulses or shakes for the first few seconds under braking. I'm thinking that I don't have warped rotors, because the shaking/pulsing goes away after the first few seconds of braking. And if I lift off the brake and reapply, there is not shake at all. To add to this, I noticed after greasing my idler arm today, that the shaking/pulsing is almost gone. If I jack the front up, and check for free play in the steering linkage, I don't find any.

What do you guys think this problem is?

Thanks in advance

 

also might check to see if the caliper may not be moving correctly. check to see how they move on the carrier bolts. a simple clean and grease(with high temp. brake grease)will fix it.

 

A very inexpensive 'shotgun' approach is to resurface the rear drums. They can also cause the pulsation by setting up oscillation in the drive axle by torque wind-up. The drum brakes quickly 'settle in' as they warm up during a snub, which is consistent with your observation/complaint.

The second barrel of the shotgun is to resurface the front rotors.

Neither barrels address the cause of the situation, which is likely to be consistent with normal wear-in of brake components.

Tip: Each time you come to a stop, roll forward 6 inches then stop, then roll and stop, then roll, etc. The purpose is to let the rotors cool evenly, without letting the pads sit and soak on one part of the rotor, while the remaining 80% sits in the cool breeze.

It's sorta like putting those little 'deer whistles' on your bumper -- you never know if it works, but it makes you feel like you did something proactive.

 

thanks for the suggestions. Will check them out.

Tip of the day:

Deer whistles - they don't work. I had them on one of my older trucks a few years back. Well, to make a long story short. The deer I hit broke them off. They really don't work...

thanks

 

LOL

Put them back on -- only, call them "Elephant Repellant" -- I doubt any elephants will knock them off.

 

Regarding the pulsing on braking, check to see if your front wheel bearings are tight. When mine were loose on an old Ranger, I would get a front end shimmy sometimes when braking.

 

Hey Y2K 7700:

what's so funny about hitting a deer? Try it and trust me you wont laugh. Plus your 7700 wont hold up worth a dam....

Lata

 

ROFL

Nothing's funny about hitting a deer -- what IS funny is people who think two little pieces of plastic with holes in them will prevent hitting a deer.

If you'd have called those whistles "Elephant Whistles" you wouldn't be whining about how they didn't work -- cuz you probably wouldn't have hit an elephant by now.

Sorry you're so touchy -- thanks for the laughs!

 

Hey y2k 7700

After hitting deer number one. I figured ANYTHING was worth a shot. Must say they do appear to get the deer's attention. I always would see the deer heads pop up in the fields. Sadly, I had more close enounters this way. Most deer, for what ever reason, actually would run. In the direction of the road.

Yup, people will buy the damdest things. Deer whistles, 7700 pounders...... no difference here.... Except my little plastic parts were cheaper :-) Just kidding around


Thanks for the laughs!!!!

 

One of my lunch buddies drives a nice Caddy. I saw it one day with an obvious deer bump. He sent it to the bump shop -- came back perfect. Drove it the very next day -- and ran into ANOTHER deer !!!

The shop fixed it very quickly the second time, as they still had the parts info on record.

Funniest thing is how he hit the deer. Seems he was running down a two-lane one night -- and was going to pass an 18-wheeler, but decided that it was better to have the 18-wheeler in front of him blocking deer -- only the deer jumped out after the 18-wheeler passed -- and he nailed the deer.

Buddy was most pissed about having followed the slow-moving 18-wheeler - and then suffering the indignity of the deer to boot!

 

The shaking/vibrating is a classic sign of warped rotors, especially if it's coming up thru the steering wheel. Thats where i'd start. It doesn't take much to warp one.

 

I believe that warped rotors would give you more of a pulsating effect through the brake pedal,
as the rotor spins it applies different pressure at the point of warpage with each rotation, thus giving back pressure through the piston/fluid/line/brake pedal.

I'm having the same prob, front rotors, pads, and hubs have been replaced and the prob still exists.

I believe the drive train is the culprit, maybe the rear brakes have a prob that acts on the shaft....

Note: the hubs were replaced because the front bearing (pass) was giving me hell. This I felt through the brake pedal, i.e. kicking back at me while making even the slightest turn. Took the wheel off and the whole assembly was rocking, now it's solid.

Sorry so winded, if anyone knows why the truck feels like it's falling apart while braking, please offer help. (There are no sensations in the pedal or steering wheel.)

Thanks,
Jerry
1997 F150 XCab DoorCrack NewMotor DoorAjarChime
Cap Rancho 5000s Heculiner....

 

Killer deer story. Reminds me of some of the one's I've seen others hit. Including some real close calls with tractor trailers and their attempts at avoiding a collision with a deer, but almost driving me off the road....

Love them deer....

FYI. Problem turned out to be warped rotors.... Replaced with MAJOR hassles of getting the dam rusted things off the hubs. Thank god for my 4 pound sledge...... Hard to believe that I didn't break anything in the removal process.....

Thanks guys

Hey Y2K 7700 keep them deer stories going. They are too funny..... I thought I was bad after hitting 2 deer in less than 3 weeks.......

 

Being a Goldwing rider I look, with keen interest, at the motorcycle-deer collisions each year -- and even remember one or two guys becoming impaled upon antlered deer.

No close calls for me, yet -- but then I try to avoid riding at dawn/dusk or after dark (cuz all the F150 4x4 drivers insist on running with the worthless fog lamps -- which cause way too much glare in my classes/helmit shield and windscreen).

I'd much rather read about deer collisions than report about them.

Happy Holiday!