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Shaky Steering Upon Breaking
http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=5&t=82126		 Page 1 of 1
Author:  Srytrucker [ Thu May 14, 2015 1:00 am ]
Post subject:  Shaky Steering Upon Breaking
i think my rotors are wrapped and causing a slight shake while breaking. I had new installed a new set of rotors and EBC green stuff brake pad last year. Now should i replace just the rotors or a complete set with pads as well. My break pads have significant thickness, so are they good to be reused or a new set should be ordered ?
Author:  DOC4444 [ Thu May 14, 2015 7:35 am ]
Post subject:  Re: Shaky Steering Upon Breaking
Do a search for "pad imprinting". Not sure about EBC pads, but many have this problem. I use Porterfield R4S, which do NOT cause this. If rotors clean up with a tiny cut, this is your problem. Use Porterfield and you will be fine.

DOC
Author:  flash7210 [ Thu May 14, 2015 9:29 am ]
Post subject:  Re: Shaky Steering Upon Breaking
A good article about brakes.
http://www.mossmotors.com/SiteGraphics/Pages/brake_discs.html

I'm a firm believer in "seating-the-pads" or as the above article calls it "bedding-in" the brakes.

You probably just need the rotors turned and resurfaced. Your pads will be fine. But given a fresh surface you will still need seat-the-pads to allow the pads to conform to the rotor surface.
Author:  tjkj2002 [ Thu May 14, 2015 11:49 am ]
Post subject:  Re: Shaky Steering Upon Breaking
flash7210 wrote:
A good article about brakes.
http://www.mossmotors.com/SiteGraphics/Pages/brake_discs.html

I'm a firm believer in "seating-the-pads" or as the above article calls it "bedding-in" the brakes.

You probably just need the rotors turned and resurfaced. Your pads will be fine. But given a fresh surface you will still need seat-the-pads to allow the pads to conform to the rotor surface.

While a great article and all true it does not tell of the #1 reason for excessive runout........................

Corrosion.

http://www.undercardigest.com/

Go to "online digital editions" and click april '15 issue and scroll to page 32/33.
Author:  papaindigo [ Thu May 14, 2015 2:49 pm ]
Post subject:  Re: Shaky Steering Upon Breaking
In my experience warped rotors typically result in "pulsing" of the brake pedal especially under light braking; sort of feels like the pedal is bouncing up and down just a tiny bit. Immediately goes away when brake pedal is released and generally is not felt when the pedal is pressed hard unless warping is really bad.

On the other hand noticeable to violent steering wheel shake after braking can result from a stuck piston in one or more disc brake calipers. Not at all uncommon after replacing rotors and pads but not calipers especially with phenolic caliper pistons, which can absorb brake fluid over time hence they swell up just enough to stick in the piston bore, as opposed to stainless steel pistons. A sticky piston won't let the pad retract from the rotor and even the slightest warp in a rotor can result in the brake grabbing and releasing hence steering wheel shake. I had an episode of this in my 1993 D250 Cummins that, until diagnosed and fixed, would intermittently cause rather violent front wheel hop and steering wheel shake. In fact I've seen this often enough on a variety of vehicles that I try to avoid doing brakes without installing new calipers unless I am positive the vehicle has calipers with stainless steel pistons.
Author:  tjkj2002 [ Thu May 14, 2015 4:30 pm ]
Post subject:  Re: Shaky Steering Upon Breaking
papaindigo wrote:
In my experience warped rotors typically result in "pulsing" of the brake pedal especially under light braking; sort of feels like the pedal is bouncing up and down just a tiny bit. Immediately goes away when brake pedal is released and generally is not felt when the pedal is pressed hard unless warping is really bad.

On the other hand noticeable to violent steering wheel shake after braking can result from a stuck piston in one or more disc brake calipers. Not at all uncommon after replacing rotors and pads but not calipers especially with phenolic caliper pistons, which can absorb brake fluid over time hence they swell up just enough to stick in the piston bore, as opposed to stainless steel pistons. A sticky piston won't let the pad retract from the rotor and even the slightest warp in a rotor can result in the brake grabbing and releasing hence steering wheel shake. I had an episode of this in my 1993 D250 Cummins that, until diagnosed and fixed, would intermittently cause rather violent front wheel hop and steering wheel shake. In fact I've seen this often enough on a variety of vehicles that I try to avoid doing brakes without installing new calipers unless I am positive the vehicle has calipers with stainless steel pistons.

Feelth e shake in the steering wheel it's the fronts,feel it in the pedal it's the rears.

Sticking pistons don't cause steering wheel shake,never seen it and I've been turning wrenches professionally for almost 19 years now.You will get a pull but not a shake,you had something else causing the issue leading upto a mild case of death wobble.
Author:  papaindigo [ Thu May 14, 2015 4:48 pm ]
Post subject:  Re: Shaky Steering Upon Breaking
Whatever. All I can say from a factual perspective is the 1993 D250 suffered several episodes of what I can best describe as violent front wheel hop and steering wheel shake, as I recall all at relatively low speed, that could be temporarily "cured" by slamming on the brakes which I would speculate "unstuck" the piston. After truing front rotors that had significant lateral run out (if that's the right term for warping), replacing pads, and installing new calipers the problem totally disappeared never to return in the next 35,000 miles of driving before my son sold the Dodge and got his CRD. No front end work of any other type was done at that time.

Draw whatever conclusions you want and I'll stick with mine.
Author:  tjkj2002 [ Thu May 14, 2015 4:59 pm ]
Post subject:  Re: Shaky Steering Upon Breaking
papaindigo wrote:
Whatever. All I can say from a factual perspective is the 1993 D250 suffered several episodes of what I can best describe as violent front wheel hop and steering wheel shake, as I recall all at relatively low speed, that could be temporarily "cured" by slamming on the brakes which I would speculate "unstuck" the piston. After truing front rotors that had significant lateral run out (if that's the right term for warping), replacing pads, and installing new calipers the problem totally disappeared never to return in the next 35,000 miles of driving before my son sold the Dodge and got his CRD. No front end work of any other type was done at that time.

Draw whatever conclusions you want and I'll stick with mine.

Excessive lateral runout was the cause and simply replacing the rotors would have helped.Granted other parts where worn also and the runout pushed it over the edge to near death wobble state which happens on solid front axle vehicles(and yes 2wds can still have SFA).You can't say that the calipers was the issue since you replaced other parts.
Author:  papaindigo [ Thu May 14, 2015 8:29 pm ]
Post subject:  Re: Shaky Steering Upon Breaking
I could be wrong but as far as I recall the front suspension of a 1993 Dodge D250 Cummins 2-wheel drive is fully independent; no solid front axle. I do agree lateral run out was the underlying cause but seriously aggravated by stuck caliper piston(s).

To be a bit more specific to the best of my memory as it's been a bunch of years:
1. the brake pedal pulsed a noticeable amount under light pressure which in hind sight should have triggered me to suspect badly warped front rotors;
2. I went cheap and just replaced pads, stupid in hind sight but;
3. experienced that intermittent bad front wheel "hop" and steering wheel shake. As nearly as I can tell the caliper piston(s) occasionally stuck causing the pads to essentially drag all the time hence heating the rotor hence causing the run out to be worsened to the point that the front brakes would grab every time the bad spot(s) in the rotor came around hence the violent front wheel hop.
4. solution was to BOTH true rotor(s) AND replace calipers.

FYI I have had stuck phenolic caliper pistons on other vehicles, including my Dad's Mercedes, but this is the Dodge was the only one with the front wheel hop and steering issue. On the others it was both front calipers and equal side brake overheating to the point of smoking; had it been only one side then you are right about pull to one side.

Point to the OP is that it's worth checking brake condition given the symptoms.
Author:  Srytrucker [ Fri May 15, 2015 12:12 am ]
Post subject:  Re: Shaky Steering Upon Breaking
Pads have enough thickness and brakes are working adequately but mild shakes are being felt in steering.
Author:  Sonorous [ Fri May 15, 2015 2:22 am ]
Post subject:  Re: Shaky Steering Upon Breaking
If you're doing this yourself I'd just pull the rotors and give everything a good clean (including the hub). It might take nothing more than a wire brush, a little elbow grease and some brakleen.

I had the same problem, but my rotors/pads were over 4+ years old at the time so I simply replaced them. I had replaced the hubs the year before and probably wasn't as careful about cleaning up the inside of the rotors as I should have been, which probably played a role. The pulsation was very faint at first but got pretty bad within a couple months. I should have addressed it sooner: front brakes quickly became rear brakes, which became fixing the stupid rivets holding the e-brake assembly together, which entailed removing the rear axles, replacing the axle seals... (you see where this is going :roll:).

I also see you're in Canada - I ended up getting the "premium" ATE rotors at Canadian tire (on sale at buy one get one free). They've worked well and have been very resistant to corrosion. If I lived in Arizona I don't think I'd bother, but I'm sold on spending the extra few bucks on rotors with better corrosion resistance going forward. I'm not saying they perform any better than anything else, but figured I' mention it.
Author:  thermorex [ Fri May 15, 2015 9:17 am ]
Post subject:  Re: Shaky Steering Upon Breaking
Srytrucker wrote:
Pads have enough thickness and brakes are working adequately but mild shakes are being felt in steering.

Guarantee you need your rotors fixed/replaced. I have had the same issue, right after getting my crd in 2010, I replaced front and rear Brakes (pads plus rotors), I got 4 cryo treated rotors and in less than 10k I started to have the wheel shake when braking. I knew the calipers are OK and I assumed the rotors were bad quality. Got some cheap advance auto rotors and in abut 3k same symptoms. Then, base on forum knowledge, I went and removed the rubber boot that is on one of each font caliper pin, this is known to swollen up and create a slight drag. Ever since, I haven't had a single rotor issue plus I gained few mpg. Apparently the brakes were dragging, but not to the point of seeing smoke coming out of the wheel or to be very obvious. And regarding Brakes, do not use ceramics, the composite/metalic ones are way more efficient, even if they make bit of noise and dust.
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