brake issue?

[vthokie]

Hey guys, here is my issue.

For a while now I have noticed that when applying the brakes I feel a pulse/shake in the steering wheel. A few months ago I replaced the rotors and pads because the original rotors had warped, so I though that this may be the case again, but it has only been a few months. I am living in an area with some steep inclines/declines, and whenever I am going down one I experience more intense shaking. During regular around town driving when it is flat the shaking is much less noticeable.

Because of all the hills around me I tend to use the brakes much more and press much harder on the pedal, so they get much hotter. I have smelled some burning before, but assumed it was coming from both sides. When I got home today I decided to smell both sides, and I noticed that only one side smelled like it was burning. The driver side is the one that is causing problems. I also noticed that the shaking tends towards the drivers side. It slightly pulls to the driver side, but mostly shakes towards it.

Now as I look back to replacing the rotors/whenever I take off the driver side wheel or have it jacked up that it is hard to spin in certain places. As I spin the wheel it feels like it catches and gets harder to turn, then it will return to being easy.

So I'd like to solve this problem. I don't think that just one rotor is warped, I think it might have something to do with the caliper. If the caliper is the problem, would it make sense that it is only hard to spin in one place, or would it be uniformly difficult?

 

[NOT ME OR SOMEBODY]

If it is hard to spin in only one place and it is a brake problem then it would seem that the rotor is warped (again). and therefore you feel a shaking in the truck when the brakes are applied.

Try to isolate what is causing the resistance. First pull the wheel off again and secure the vehicle with a solid jack stand or something that you know will positively hold the weight of the 4runner.

Push the brake pads back against the caliper enough to cause the piston in the caliper to move and enough that there is a air gap between your pads and rotor. While doing this watch the pistons and make sure they all move and none are stuck.

Try to spin the rotor now and see if there resistance is gone. Yes = rotor is warped (again). Now the question is why ?

The Burning smell makes me suspect a stuck piston in the caliper.

If the resistance is still there then you have to do other things to locate the cause. It's all about isolating possible causes and narrowing down to the root cause.

Caution: when you let the truck back down be sure to pump the brakes and be sure they are in fact working before you take off driving. Its likely that after pushing the piston back in the rotors that the brakes will not apply right on the first push of the pedal.


Another little tip: if you find yourself in a situation where you had to brake hard to stop or to slow down on a long steep hill, ect.. When you do stop do not sit in one spot with your foot on the brake, roll forward a bit and roll forward a bit again. This will help spread the heat from the brake pads. Staying in one position will put all that heat in one area of the rotor and promote wapage of the rotor.

GO HOKIES!!!

 

[vthokie]

alright cool, sounds like a plan. I'll be getting to it this weekend if I cant take a look at it tomorrow. If a piston in the caliper is sticking would it not be safe to drive? I mean I have had this issue for a few months and its been fine besides the shaking. On another note I have rotors with a lifetime warranty, so if it is warped it will be free!

 

[vthokie]

Ok so I just took it for a drive and noticed a few things. From a cold start the brakes are smooth and operate like normal. Once they are heated the shaking begins. If I was to let them cool buy not using them they would return to normal, but if they are hot and kept hot, the shaking gets pretty bad. After I parked it I noticed that the drivers side produced a lot more heat. I didn't measure the temperature or anything I just put my face up to both wheels and there was a pretty noticeable difference. Would a caliper being stuck cause these changes? or would it be a constant drag? It seems like it could be a combination of the two( bad caliper and rotor), or the caliper may be dragging constantly, but it doesn't affect the ride until it is heated.

 

[Jon]

That's got stuck caliper piston written all over it.

Remove the calipers, and piston boots, apply grease and pull all the pistons full in with a c-clamp. If any feel stuck then install them back on the truck. Get a friend to help by holding a pry bar between the piston and rotor. Apply brakes till the piston is extended then pry it back in, repeat a few times adding grease. Fixed mine and I didn't even need new rotors. When your done bleed from the furthest from the master cylinder in. Good luck

 

[vthokie]

Alright awesome, Thanks for the help guys i'll be giving this a try this weekend.

 

[NOT ME OR SOMEBODY]

Let us know how it goes. I feel a bit of obligation to assist a Hokie In need.

I am not from that area and did not go to VT, But my inlaws both graduated from there in the mid 50's. So being a VT Football fan is mandatory. We've been to Lane Stadium several times over the years to see games, and sometimes stayed at the Inn, it was always great.

I'm thinkin the rotor is warped also but you'll have to figure that one out.

Maybe after checking the calipers and re-assembling and IF the pulsing or vibration is still present I might put some small lines on the rotor with a marker or something in different spots, and then rotate the rotor and see if the marks get wiped off un-evenly.... Yes = rotor is no good.

Not sure what Jon is saying, ("When your done bleed from the furthest from the master cylinder in. Good luck") but unless you open a brake line and let air in the system you should not have to do any bleeding of the brakes unlees the pedal just doesn't feel right when you apply the brakes.

Be safe
and
Good Luck.

 

[vthokie]

Alright well i did replace the caliper on saturday. There was a frozen pistion. Most of the vibration is gone, but i do believe the rotors are slightly warped from the excessive heat caused by that stuck piston. I have a lifetime warranty on my rotors, so i will be able to get new ones and replace them within the next few weeks. Thanks for the help guys.

 

[NOT ME OR SOMEBODY]

Great!!!! too bad you couldn't change the rotor when you had it apart. But the more you work on it the you'll get to know it. If you do the rotors be sure to look around in there for other things while its apart. Axle boots leaking steering and suspension parts that have looseness. It should all be tight and no abnormal movement.

Good luck.

Hokie Fan too.

 

[vthokie]

Well I took it for another drive along a back road in the mountains and it still shakes when braking. It isn't as bad, but it is still noticeable. There is still a noticeable difference in the temperature of the driver side and passenger side brakes. (driver is hotter). The odd thing is that the driver side has a new caliper. Could a warped rotor on one side cause this difference in temperature? It is hot right now, but hopefully later today when the brakes cool down I can go take a look and see if there is anything noticeably wrong. I did notice that when I apply the brakes and hold it in one position, the pedal seems to push back and pulse sort of. I dont think there would be an issue with the abs. If the abs was involved how would I know what to check?

On another note, how did you like the Inn at Virginia Tech, NOT ME OR SOMEBODY? I've been inside for banquets, but I've never stayed there.

 

[vthokie]

Well i took your advice NOT ME OR SOMEBODY and tried that line test on the rotors.
Driver

Passenger

all i had was a blue highligher, but you can still see the "tail" which shows it is rubbing.

 

[NOT ME OR SOMEBODY]

Yes I see the pics but I can't tell much, it looks like it is pretty evenly distibuted.

Can you tell more in person?

I would expect to see places where the marks were rubbed off in an area and then it would be untouched or at least lighter in another if the rotors were in fact warped.

You have to realize this is a very crude shade tree mechanic way of checking, and the proper way would be to use solidly mounted a dail indicator or something that could closely measure the run out /deflection/warpage or whatever you like to refer to it as.

anyways no harm done in trying.

Best wishes from a HOKIE FAN

 

[vthokie]

Yeah i know what you mean, It is definitely easier to turn in some places, and some of the lines in those areas were untouched. I just made the areas where it rubbed bigger to show how it was rubbing. I appreciate the help man. I'll be replacing the rotors over the 4th of July weekend, so hopefully everything works out.

 

[achen]

Hey Guys,

It seems like I have the same problem. My problem is when I apply the brakes at high speeds around 40mph and above, the steering wheel vibrates and shakes greatly. Is this due to a frozen caliper? if so which side?
I changed all 4 rotors and pads last summer. The mechanics told me it's my rotors and theya re warped in the front. I got those drilled slotted rotors, cost about $90 a piece. expensive rotors. Another mechanic said its my calipers, rotors and pads. I feel nobody is being honest. Now I am thinking it is caliper but dont know which one. I really need your help. i cant trust any mechanis out there.