dragging front brakes

[OB_WAN]

I recently rebuilt my front calipers and bought new pads and rotors. I'm now experiencing some issues with the calipers dragging(when lifting the wheel, and turning it, I can feel the front pads grabbing the rotor allowing it to spin only 1/4 turn).

I noticed a few odd things during the rebuild/install. 1. the caliper pistons were corroded at the base and up the sidewall 1/4 way, pitted. 2. when installing the pads, I had to compress the pistons ALL THE WAY, some significant compression had to be done to fit the pads over the rotors.

I've got stinky brakes(dragging) and just removed one of the wheel hubs and noticed burnt bearing grease after 1month of running. wasn't there before. on a side note, I didn't have the appropriate hub nut socket so hadn't properly torqued the bearings so that could have been part of the prob(spinning bearings) but I'm guessing a lot of the burnt grease was caused by hot hubs due to the dragging rotors.

parts used for replacement were the best I could get from Napa/Reibees.

I'm guessing something is wrong with the calipers or pads causing the dragging but wanted to get your input. also guessing rebuilt calipers from the local autozone will be sufficient for replacement?

Thanks

 

[Agnem]

.... when installing the pads, I had to compress the pistons ALL THE WAY, some significant compression had to be done to fit the pads over the rotors. ...

Never never never EVER allow this when doing a brake job. You were doomed from the start right here. Disc brake assemblies must go together with zero resistance. It doesn't sound like the pistons retracted fully, and/or you got the wrong parts. At this point, you may as well throw all that stuff out and start fresh including a full repack of the bearings and replacement of seals. If you heated up your rotors that bad there is a good chance they are shot too. Sorry!

 

[OB_WAN]

the pistons were retracted fully and I mean FULLY. Once retracted, there was zero resistance on the rotor. The resistance is occurring after driving around the block to set the pads on the rotors(or simply pumping the brakes hard). Jacking up the wheel and trying to spin it. It's acting like a stuck piston or master cylinder. I haven't jacked up the passenger side yet to see if it's similarly stuck but I think it's primarily the driver's side.


I was curious about the rotor thickness and pad thickness since different D60s have thinner/thicker rotors and corresponding pads to compensate. I got the rotors/pads together at Napa but the parts guy could have screwed up on the order.

 

[Ironman03R]

Change your brake hoses. They can breakdown inside and hold pressure in the calipers.

 

[86.9]

Second the brake hose replacement. Mine were bad on both sides and caused problems intermittently. I had some stainless steel ones made which I really like by a place out in California. They used some of the stuff from the stock lines and did a real nice job. Not too expensive either.

Jeff

 

[OB_WAN]

thanks for the tips on the brake lines. they do look really cracked on the outside so guessing the inside isn't too healthy either.

86.9, what was the name of the place that made your lines? I've swapped steel braided lines in the past and they've made a world of difference for getting rid of the "squishy" response.

 

[86.9]

The place is Baker Precision Products. 562-427-2375

 

[OB_WAN]

update: I cooked my wheel bearings well enough that I am now changing them out. In addition, I thought perhaps the brake lines were deteriorating so got some new brake lines. And because I was worried about the corrosion on the caliper pistons, I got new calipers.

Here's the problem now:
with the pads in the new calipers, I can no longer fit the brakes over the rotor. The rotor measures 1.25 which is in spec for this vehicle. The ID at the brake pads measures 1.15. New calipers should be fully compressed(and they seem to be) so the problem seems to be with pad thickness.

The pads measure ~.660 right now. I called Napa and they pulled 3 brands off the shelf that measured the following:
wagner thermal quiet - .666
raybestos professional grade - .676
raybestos service grade - .653

My pads compared to the min thickness pads only gives me .014 difference. Looks like I need .100

I'm going to call Autozone and see what kind of pads/thickness they come up with.

Has anyone else run in to a similar issue? I'm even considering calling Ford and getting some factory pads from them or asking if they'd be willing to measure them for me.

 

[jwalterus]

when I did my brakes last month, I used these pads: http://www.oreillyauto.com/site/c/detail/OBR0/MKD120.oap?keyword=mkd120

also these rotors: http://www.oreillyauto.com/site/c/detail/BBR0/8160394.oap?keyword=81-60394

and these calipers:
http://www.oreillyauto.com/site/c/detail/A1C4/184229.oap?keyword=18-4229
http://www.oreillyauto.com/site/c/detail/A1C4/184230.oap?keyword=18-4230


my brakes are wonderful now

almost forgot, you need to retain the bolts holding the brake line to the caliper since the new ones come with the washers and all other hardware but not the bolt

 

[Agnem]

Are these pads new too? Don't try and use the ones you had in your last overheating scenario. You have the right idea now. They should definitely all go together without any force or friction.

 

[OB_WAN]

all pads I checked are the same thickness as the ones that are on there now. I was able to compress the caliper pistons down a little further to get them to slide freely over the rotors. After bleeding the brakes, there's still some drag on the rotors but I'm guessing that drag is from the new piston boots they use on these calipers. They protrude quite a bit past the piston and due cause the piston to want to sit against the rotor. Odd.

But I'm "thinking" that something was up with the old pistons/lines causing some significant drag and unbalanced braking(when I'd brake, it would sometimes pull to the passenger side but the driver's side was consistently overheating more frequently which tells me there was a sticky piston/boot/line that restricted pressure in both directions on the driver's side)

 

[Agnem]

Are you a politician? You managed to give a complete response without answering the question.

 

[OB_WAN]

I side-stepped the question because you wouldn't like the answer

the pads are "new" but not brand new. because I couldn't afford another pair of $80 pads I used the cooked pads. the driver's side rotor is lightly warped now and the pads match up to the rotors so I put them back on. they're severe duty pads so guessing they're adhered to the backing pad significantly better than a pair of duralast or similar.

The brakes are still dragging (tire will spin but I can feel resistance and can only get one turn before it stops) so I dug in to alldata and here's the problem list:
* Pinched or internally collapsed brake hose. Hydraulic pressure from the master-cylinder forces brake fluid through the hose, but residual pressure is then trapped behind the restriction in the hose causing the brakes to drag.
* A blocked compensating port in the master-cylinder. The compensating port allows pressure to quickly equalize upon the release of the brake pedal.
* Lack of clearance between brake master-cylinder and push rod. Lack of clearance will prevent the master-cylinder piston from fully retracting in its bore. This can block the compensating port, and maintain hydraulic pressure in the brake system.
* Oil contamination of the brake fluid. Oil (or any other type of petroleum product) that has contaminated the brake fluid will cause the rubber seals in the master-cylinder and the calipers to swell. This swelling causes the caliper pistons to bind and stick.

might be an issue with the compensating port. If my brake pedal return spring is worn, it might not be completely releasing the master cylinder which is where the compensating port would allow the fluid to return. Or perhaps the compensating port is gummed up a little or the piston is worn not allowing full retraction. the only thing is, it's not forcefully holding the brakes, they're just dragging enough to heat up.

Part of me is still looking at those thick caliper piston boots. why would they protrude from the piston so far? on the old calipers, the boots were clearly pressed around the pad and due to the heat, the backing plates on the pads were stuck to the boots.

 

[MIDNIGHT RIDER]

This probably ain't got anything to do with your situation, but did you wire-wheel-brush and grease all the caliper run-ways ??

Grit and rust in the ways can cause binding and dragging, especially when an internally collapsed hose is thrown into the mix.





You guys ought to work in a public tire-shop for a while; it is plumb scary what I see behind people's wheels on a daily basis.

 

[THECACKLER]

I troubleshoot a problem like this by jacking up the wheel that is dragging and spin it while I crack loose the bleeder. Doing that will relieve any residual pressure in the hydraulic portion of the system and rule out or in the hydraulics as the source of the problem.