Puzzling Brake Problem HELP!

Just bought a 2002 VTEC and I think I got burned. The brakes drag HARD on the calipers, mostly on the front but sometimes in the rear as well. I have done everything I know how to do to fix the problem, including...
torn down and inspected all three master cylinders
torn down and inspected calipers/seals/pistons
bled and rebled the system
greased the slider pins and aligned the front end...

still the system is dragging. The only part I have not fully inspected is the PCV valving system, which I know very little about. I did remove the valve and squirt some compressed air through it, seems to flow more readily one direction than the other. Could the valve be bad and be preventing the pistons from retracting? What the hell is going on with this bike!?!?!:unsure:

 

Wow, not the only one with brake problems tonight!

I came here to post a similar question, you beat me to it, at least I'm not the only one with brake problems tonight...

My symptoms are a little different. Only my front are the problem. Perhaps if I say what I've done to troubleshoot it, that might help someone help us both?

I bought my '98 as a neglected beast that sat outside way too long, have been "restoring" it since June. When I got it, the front brakes were dragging the rotors bad enough that it took a little force to spin the wheel. The brake pads needed replacing, and the pistons had some areas with rust, that would have to be pushed back into the caliper with the new pads. As much as I hated to I didn't see a choice but to carefully remove the rust with 1000 then 1500 wet/dry paper, then polished the crap out of them with a buffing wheel on a dremel and metal polish. This removed some of the gold coating, but the things are as smooth as glass and just as shiny, I *think* they're ok. I didn't pull the pistons from the caliper, which might have been a mistake.

I put it all back together and they still drag the same. It seems to me that if it was a problem with the master cylinder, or a brake line collapsing, or anything else "above" the calipers, that letting fluid out of the bleeders would release the pressure and therefore the pads from the rotors. I've done that, a little fluid comes out, but they still rub the same on both sides.

So, would the next step be to pull the pistons out and clean everything to perfection? Should the seals shown here as 1,2, and 3 be replaced or should I try cleaning first? Any other suggestions?

 

i would check the return port in the master cylinder resivoir, especially if the fluid was dirty. Beyond that, it is a good idea to go ahead and remove and replace the seals, but if the pistons move in and out easily, that probably isn't the problem. Seems like I've been learning a lot about brakes here lately!!

 

if opening the bleeders does not release the pistons then it cannot be a problem with the master cylinders. The problem is in the calipers. The seals are what acts as a spring to retract the piston on the calipers: they are asymmetrical and they cant slightly in the cylinder to put retracting pressure on the piston , so having set for a long time the seals may be gummed up and not retracting the pistons. Try replacing the seals and cleaning the pistons and bores, then lube them with brake fluid before reinstallation. and be shure to get the new seals in the correct orientation.

 

As one who works in the brake manufacturing industry .. (check the brakes on any Corvette .. made in Australia) I can tell you this ...

The seals do act as the retraction device for the piston, but they are symmetrical (square or rectangular in setion) .. the groove they seat in has a taper in the bottom to exhurt pressure to the front or disc side of the seal. The seal "grabs" slightly on the surface of the piston and pulls it back by the mechanics of wanting to return to its "normal" state.

The surface finish of the piston is a critcal factor in retraction ... so dont go polishing to a mirror finish.

I'd pop the pistons and make sure everything is clean inside look for scoring etc in the bores...

I think you'll also find that each bore is of a slighly different diameter depending if it is the leading or trailing bore. (hence the three different numbers for the seals on the microfiche)

 

New master cylinder and braided hoses are your best friends

 

Thanks for all the replies, I'm going to order the seals for both sides and hopefully that will fix it...perhaps thats both of our problems, hycide...

Any of yall thats done this before care to share any tips on getting the old seals out and putting the new in, the service manual is pretty vague (remove old, install new...)..its my first timechanging these seals...I haven't got it apart yet to see if its just that simple or not.

In looking at the microfisch, again, here it looks like for the left caliper the "top" seal set is 2, the middle is 3, and the bottom is 2....and for the right its 1 for the top, and 3 for the middle and bottom...am I reading this right? Just want to make sure I order all the right stuff to begin with..and know which goes where once I get the stuff...

 

here's the funny part, according to the mechanic at the local shop, the seals are fine. Look fine to me as well.

Barring that, my question is whether the valves under the seat, PCV or whatever, can cause a dragging situation if one or both goes bad.

The reason that I ask this is that it seems a little odd that seals on teh front and rear calipers would go bad altogether and at the same time...

 

If you haven't, I'd try cracking the bleeders and see if the dragging gets better after releasing any pressure, if not I think that would rule out anything "above" the calipers and the problem would be what I'm pretty sure mine is, the seals and/or pistons.

As far as troubleshooting this mostly annoying LBS if its something else...wish I could help there....

 

:unsure:OK....I give up. To date, I have
- torn down and inspected each MC on the bike
- replaced both Proportioning Valves
- Replaced seals in the front calipers
- messed with the wheel alignment again and again and again
- swapped the front lines for a set of braided ones laying around at the shop ( too long but work for troubleshooting)

Still the front brakes drag....less than before (they don't lock up) but they drag, and especially when the bike is test ridden and stuff gets warm.

Any Friggin clue what's going on, the local mechanic certainly has no idea...?

 

Missing a washer in the axle assembly? Thereby forcing the rotor against one of the calipers?

 

Last month I took my 2004 VFR to the shop for a new front tire. I was enjoying my new Pilot Power but after a bit of riding I noticed a shudder when I applied the front brake. Immediately I pulled over and touched the front rotors. One was HOT! The technician had improperly installed the right rotor (reversed the spacers) and I had been dragging a pad. The rotor was warped and I got a new brake job out of the deal.

This is a longshot, but could the same thing have happened to your VFR?

 

Solved!

Hycide..
I JUST finished doing part of what you did this afternoon, rebuilt the master cylinder and put new seals in the calipers...got it all together, bled, and *&%$!! Same bad dragging...I read somewhere on some board recently about fork alignment causing similar dragging on someones bike...I loosened all 4 bolts that hold the tubes, gave everything a few good jerks back and forth, and the wheel spins like it should now!!!! :smile::smile::smile: Almost a full rotation with a modest spin..Guess I learned a lot about brakes in the process...$60 lighter in the wallet for the parts I probably didnt need, but on the bright side, my system is practically new now. I hope thats your problem as well. Keep me posted, curious if that is your problem too. Might not hurt to loosen the big bolt too, wasn't necessary on mine though...

Hope this helps someone else down the road who has the same problem too....