Pulsing Brakes

[MakeItADouble]

Hey all. This is my first post.

First off, I'd like to to thank you guys. I've saved more then a few Benjermans because of the forums here.

Drive a 98 Jimmy 4x4 (You Blazer folk have more info.). Had a clicking noise coming from the front wheels. Also had pulsing brakes at high speeds. Thought it would be the bearing assembly and bad rotors. While working on replacing the bearing hub assembly I found A LOT of play in the wheels of both sides by putting a hand one the tires at 6 and 12 oclock and pushing back and forth. Again I thought it was the bearings.

I replaced the bearing hub assemblies (according to the HOW TO on this site ), put on new rotors, and pads.

I found that the old brake pads were almost new looking at the top ends but severely worn out on the bottoms especially the inside. The driver side bearing was completely shot the passenger side seemed okay, but I replaced it anyway.

I'm still getting the play in the tires when pushing back and forth on the tire at 6 and 12 oclock. My brakes still pulsate when applied (more so at higher speeds) and I've got a slight vibration in steering wheel at higher speeds.

Where do you guys think I should look next? Ball Joint? I didn't check them because I know nothing about auto mechanics only what I research online.

[BlazerLT]

movement at 6 and 12 o'clock usually means ball joint wear.

This could be causing an alignment problem which can cause the pulsing.

Also don't rule out a bad rotor right from the store.

[DINO55]

MakeItADouble.

Hopefully before you installed your new rotors and pads, You cleaned and greased the shit out of your caliper slide pins?

[muddog321]

Yep, could be lower ball joints, tie rod ends, pitman arm etc.
As for the brakes, did you do the rears too cause they are often the source of the pulsing and unless you disassemble the rears off the brackets and look at both sides of the rotors and pull the slide pins out of the bracket and grease them (if they are not frozen) then you aren't done yet. If this has 80-100k replace those rear calipers too cause they do not like having the single oiston pushed back in (usually jam or freeze as soon as you do a hard stop - been there before) so for rears buy "loaded" calipers with the pads, caliper, bracket, and pins - saves you alot of pain and $$ - really.

[MakeItADouble]

Thank you folks.

The truck is approaching 115,000 miles.

I'll be replacing the ball joints when I get back from Florida next week. I'm getting married. There was play in the wheel with the old rotors as well. I'm going to get an alignment done too.

I didn't grease a damn thing except the ball joints. But I will get on that.

I replaced the rear brakes last summer. Again I didn't grease a thing. I didn't know I had too. I check and grease them ASAP.

I'll look into how to check the other items you guy mentioned as well. Thanks again for your help. It helps me out a lot and saves me cash.

Knowing is Good!

[2000blazerls]

Can you grease the pins AFTER you put new pads on? I of course would have done it while I was putting them on but a..a friend! Yes! A friend of mine may have put new pads on and not greased the pins. Yes, my friend is asking this question, not me. I am not even here now really.......

[DINO55]

Originally Posted by 2000blazerls

Can you grease the pins AFTER you put new pads on? I of course would have done it while I was putting them on but a..a friend! Yes! A friend of mine may have put new pads on and not greased the pins. Yes, my friend is asking this question, not me. I am not even here now really.......

YES, It's never too late to grease the slide pins, make sure they are clean before you re-grease and install them. if they are dirty or rusty like mine were, wire wheel them first

[BlazerLT]

Originally Posted by muddog321

Yep, could be lower ball joints, tie rod ends, pitman arm etc.
As for the brakes, did you do the rears too cause they are often the source of the pulsing and unless you disassemble the rears off the brackets and look at both sides of the rotors and pull the slide pins out of the bracket and grease them (if they are not frozen) then you aren't done yet. If this has 80-100k replace those rear calipers too cause they do not like having the single oiston pushed back in (usually jam or freeze as soon as you do a hard stop - been there before) so for rears buy "loaded" calipers with the pads, caliper, bracket, and pins - saves you alot of pain and $$ - really.

For testing the tie rod wear, the play is usually at the 3 and 9 o'click position.

[MakeItADouble]

Hey folks. I've got some feedback for everyone.

I got married.... Came back and replaced all four front ball joints last weekend. This took all the 6 and 12 oclock movement out the wheel. The job took almost 12 hours... because I stink as a grease monkey.

I used the Ball Joint replacement in the "how to" on this site. It was invaluable to me. As I stated before, I'm no mechanic. I don't play one on TV.

The only diviation from his instructions was that I removed the spindle on the driver side as well. It was only one more nut.

I greased that crap out of the brake caliper pins as suggested as well and checked for loosness in the other suspension. I didn't find any.

The ball joints themselves were IMO totally shot. The bottom joint bolts were so loose I question whether they were ever torqued properly. The boots on three of four were popped but still held grease.

To recap everything I recently replaced on the front end; The rotors, pads, Hub assemblies, and all the ball joints. The truck drives like a dream and has shown a good increase in fuel efficiency. I got a very, very slight pulse in the brake pedal when braking. I'm going to check the rear brakes maybe this weekend to see if they might be contributing to that. A set of new tires and an alignment and I think I'll be golden.

Thanks again guys. This site saved me a bundle!

[DINO55]

I'll bet your rear rotors are warped because the caliper slide pins are frozen (rusted) and the constant contact with the inside rear pad on the rotor caused one side to warp... Wire wheel the old pins if they aren't to bad and grease the shit out of them. Otherwise get a new set. Post back with the final results please

[BlazerLT]

Originally Posted by MakeItADouble

Hey folks. I've got some feedback for everyone.

I got married.... Came back and replaced all four front ball joints last weekend. This took all the 6 and 12 oclock movement out the wheel. The job took almost 12 hours... because I stink as a grease monkey.

I used the Ball Joint replacement in the "how to" on this site. It was invaluable to me. As I stated before, I'm no mechanic. I don't play one on TV.

The only diviation from his instructions was that I removed the spindle on the driver side as well. It was only one more nut.

I greased that crap out of the brake caliper pins as suggested as well and checked for loosness in the other suspension. I didn't find any.

The ball joints themselves were IMO totally shot. The bottom joint bolts were so loose I question whether they were ever torqued properly. The boots on three of four were popped but still held grease.

To recap everything I recently replaced on the front end; The rotors, pads, Hub assemblies, and all the ball joints. The truck drives like a dream and has shown a good increase in fuel efficiency. I got a very, very slight pulse in the brake pedal when braking. I'm going to check the rear brakes maybe this weekend to see if they might be contributing to that. A set of new tires and an alignment and I think I'll be golden.

Thanks again guys. This site saved me a bundle!

Make sure you take the weight off your front wheels and grease the crap out of the new ball joints every 5000miles or they will be toast in a year.

[JustRainMan]

Yeah I'm Going To Say Your Lower Ball Joints. Most Definately If You Have Movement/excessive Play At 6" & 12" O-clock 9 Times Out Of 10 It's Your Ball-joints.

[MakeItADouble]

Originally Posted by DINO55

I'll bet your rear rotors are warped because the caliper slide pins are frozen (rusted) and the constant contact with the inside rear pad on the rotor caused one side to warp... Wire wheel the old pins if they aren't to bad and grease the shit out of them. Otherwise get a new set. Post back with the final results please

Alright. Finally finnished everything...

Took apart the rear brakes, etc.
The rear slides pins were in fair condition with the exception of one. It was completely frozen/rusted in. I disassembled them and wire wheeled the crap out of em. Greased them until they were shitted. Bought new pads and rotors. The rotors were in pretty bad shape on the inside. Big chunks taken out, etc.

Now my GMC is now smooth as glass.

Thanks guys. I really appreciate your advise.

[DINO55]

Glad it worked all out for ya... "Smooth as Glass"