View Full Version : Well this is neat. Puzzle question to everyone
Hi everyone,.. So I started my MK III today for the first time since winter, and well I'm getting that the rear tires are stuck. There is no free play in them at all. The car can barely move they are so locked.
Now before i lift it and take a look, any ideas what might be causing this?
AJ Roadster NJ
03-10-2011, 02:16 PM
Was it parked over the winter with the emergency brake locked tight? What is your rear axle and brake setup (discs, drums)? Does this happen with the transmission in neutral, or do you just have the clutch disengaged?
Thanks for asking.. I have disc rear brakes, and no the e brakes were not applied and yes tranny is in neutral. I lifted the car and finding that my break pads are totally locked onto the disc brakes. I can't even remove the caliper it is so tight. suggestions
Mr Goodwrench
03-10-2011, 04:58 PM
Are your front wheels locked also?
FFR2166
03-10-2011, 04:59 PM
Youre gonna need a bigger hammer....... no seriously, maybe a prybar to separate the pad from the rotor. You could try a C-Clamp if you have one large enough to try to push the piston back in, you would actually be pushing the caliper towards the outside of the car to get some clearance. You could crack the bleeder screw as well to relieve some of the pressure. Good Luck freeing things up and maybe next year take it out a time or two in the winter to keep things from rusting.
Mike
so it's just a matter of muscle to separate the pad from rotor. Is this because I put the pads in wrong, or because I didn't touch the car at all the whole winter? I will try to loosen the bleeder screw as well. hopefully that will work.
Thanks Mike
Are your front wheels locked also?
No just the rear,...
AJ Roadster NJ
03-11-2011, 07:09 AM
I don't understand what would've caused this to happen.
Renegadezx
03-11-2011, 07:54 AM
I see this all the time in vehicles that sit over the winter. Just be careful, if you get too crazy you can damage the shoe. You shouldn't need to open the bleeder, just gently pry the shoes away from the rotor.
Rootbeer Roadster
03-11-2011, 08:02 AM
The morning after a rain storm or washing the car my Miata does the same thing. the rear pads rust to the rotors. My guess on the cause is the amount of metal in the pads. I'm able to power it loose in reverse. I get a loud clunk when it breaks free. Your situation may be more severe than mine.
Mustang Man
03-11-2011, 08:12 AM
First off, they are PADS, not SHOES. Shoes are for drum brakes. Just getting the right wording out there.
Secondly, DO NOT USE A C-CLAMP! the rear calipers use a threaded parking brake/piston adjuster. If you push on the piston with a c-clamp you will damage the caliper. Unfortunately, the only way to get the piston to retract is to get to the face of the piston and thread it back into the caliper with a caliper tool.
Your best bet is to remove the two caliper bolts and then whack the caliper with a plastic faced deadblow hammer and/or pry the caliper UP and away from the rotor hub.
Usually if it is just stuck pads the engine power will break them free (put it in gear and dump the clutch). Make TRIPLE sure it is NOT your clutch disc stuck to the flywheel. Put the trans in gear, have someone push the clutch pedal in, and then turn the engine over with a breaker bar. If the car moves, with the pedal in, your clutch disc is stuck...
HTH...
Mark
rich grsc
03-11-2011, 09:44 AM
What Mark said! Put the tranny in 1st or reverse, it should break free, it not you need a bigger engine. ;)
thanks everyone for your comments. wanted to give you an update. opening the bleeder did the trick (thanks Mike). There was simply no other way. That thing was stuck on there like you wouldn't believe. But once I opened the bleeder it came loose. Apparently it was only on one rear wheel and not both. Which leads me to wonder how/why this happened. I will admit that I did not push in the piston when I put on the pads and it was a tight fit over the disk, (but nothing like this).
Mark, i will use the piston adjuster (good call. Thanks).
Speculations as to why this happened is welcomed as i do not want to repeat the mistake.
Thanks
btw,.. putting the engine in gear and moving it didn't really work. It moved the wheel but very very tightly and as soon as I stopped it would stay locked. It didn't "break" it ffree.
Renegadezx
03-11-2011, 11:21 AM
I wonder what type of "pads" you are using? I've seen some swell and with the parking brake mechanism, it could be similar to having the parking brake set. What worries me is the bleed screw releasing it. If I see this on front brakes, I suspect the hose running to the caliper, but on the rear, don't these both run through one hose? Is it possible you have a kinked brake line to that caliper?
AC Bill
03-11-2011, 02:12 PM
It is odd that there would still be hydraulic pressure holding the pads tight against the rotors. They should have backed off the rotors the last time you released the brake pedal..
Issue with the master cylinder perhaps?
Not sure. All I know is that I removed the caliper, used and piston adjuster to push the piston back in, replaced the pads, put back the caliper, then bleed the brakes, and it seems to be fine. There is play in my wheel when brake isn't on and it stops pretty well when brakes are pressed.
BTW,,, I took her out for a drive around the neighborhood FOR THE FIRST TIME EVER<<< and BOY WAS IT AWESOME!!!!!!!!!!!!!
Pierre B
03-11-2011, 03:30 PM
You may only need to tap the edges of the steel discs slightly with a steel hammer, to get a harmonic vibration going. That might be sufficient to break the pad to disc rust bond. This would be sort of like ringing a bell and it just might do the trick. Just don't whallop the discs since you don't want to chip the edges!
CRZN 427
03-11-2011, 09:14 PM
When you relieved the pressure on one bleed valve, you also releived the pressure on the other rear pads.
Both rear calipers have their own bleed valve to get air out of the system, but once the air is out of the system, both pads are pushed against the discs with the same pressure head.
The front brakes have individual lines, the rears are on the same supply line from the master cylinder.
Regards, Rick.
beeman
03-11-2011, 09:40 PM
Had the same thing happen with the rear brakes of a 2001 Ford escape with the parking brake. it was FWD, I could drive back and forth, but no luck, just left a skid mark from the rears. Tried penetrating oil, etc. Couple of hard taps on each caliper with a metal hammer broke the rust free and i was all good.
for sure it wasn't a rust sticking issue. It was the fact that the pads were squeezing the disk tightly. I had moved the car slightly before removing the caliper so the disk did move. It was just very tight. Like moving a car with e brakes engaged. so no tapping or anything would have done anything. I needed to remove the caliper all together.
When you relieved the pressure on one bleed valve, you also releived the pressure on the other rear pads.
Both rear calipers have their own bleed valve to get air out of the system, but once the air is out of the system, both pads are pushed against the discs with the same pressure head.
The front brakes have individual lines, the rears are on the same supply line from the master cylinder.
Regards, Rick.
Uhmm,.. question, how can I make sure the brakes were bled properly? what am I looking for in brakes with air in the line? (soft brakes?) Also, anyone know the specific torque ratio on the caliper bolts?
dv/dt
03-12-2011, 09:35 AM
I would check and make sure that the master cylinder is releasing COMPLETELY. What master cylinder are you using? When the brake pedal is released and the M/C fully releases it becomes an open system allowing fluid to return to/from the M/C reservior. It cannot hold pressure! For some reason yours is holding pressure in the rear circuit, regardless of the fact that you now have them released and drove it around the block it will likely come back the first time you warm up the fluid. Pics of the M/C set-up would help. Others have had the same issue in the past and where to look depends on you set-up.
Cheers, Rod
Well Thank you Rod, because guess what??? It happened again.!!! tried to take her out today and same issue.
was about to lose my mind until I read you post.
does this help?
http://i105.photobucket.com/albums/m207/rome_011/IMG_2104.jpg
Jeff Kleiner
03-12-2011, 04:40 PM
Your balance bar is misadjusted and not allowing the rear master cylinder to fully release.
Jeff
oh thank you. It sounds like a fixable problem. but,.. please explain that in greater detail. Most importantly what do i do exactly.http://i105.photobucket.com/albums/m207/rome_011/IMG_2104-2-1.jpg
If X is the balance bar do I adjust A or D or E. in which direction? What exactly am I trying to achieve? a straight line. How far out. etc etc. I'm trying to get exactly what I need to do that way I won't have to do it again.
Also, will I have to open the bleed valve to release the pressure all over again?
as always, Thank you for your responses.
BTW, While I'm at it. My brake pedal is NOT,, (edit, I meant to write NOT very well adjusted). very well adusted. The brake lights come on (without me in the car) because the brake pedal doesn't spring back far enough to push the brake sensor. What is the best way to fix this? by adjusting A and D until it does?
dv/dt
03-12-2011, 07:09 PM
From Wilwoods site:
http://www.wilwood.com/PDF/DataSheets/ds252.pdf
Sorry, I don't have that system so I can't add much more. But it would appear that from their drawing the two nuts, A and D, should be tightened against the pivot blocks on the balance bar to keep the pushrods locked in place once they are adjusted. IF the rod that nut D is on goes to the rear M/C cylinder then it may need to be screwed further into it's pivot block so allow that piston to retract further.
Are your remote reservoirs higher than the master cylinders?
Cheers, Rod
Renegadezx
03-12-2011, 07:45 PM
I think you are on the right track, but I'm now bothered by the brake light comment. Sounds like the pedal is not returning far enough to let pressure return from the rear calipers? Do you have a return spring?
I think you are on the right track, but I'm now bothered by the brake light comment. Sounds like the pedal is not returning far enough to let pressure return from the rear calipers? Do you have a return spring?
I will have to take a look at it again as I actually don't recall exactly if it has a return spring. I don't think so. Will let you know. The difference is very slight though. pedal only requires a small nudge.
From Wilwoods site:
http://www.wilwood.com/PDF/DataSheets/ds252.pdf
Sorry, I don't have that system so I can't add much more. But it would appear that from their drawing the two nuts, A and D, should be tightened against the pivot blocks on the balance bar to keep the pushrods locked in place once they are adjusted. IF the rod that nut D is on goes to the rear M/C cylinder then it may need to be screwed further into it's pivot block so allow that piston to retract further.
Are your remote reservoirs higher than the master cylinders?
Cheers, Rod
Thank you so much again Rod. this will be very helpful. However, if anyone is familiar with this system please advise. I always prefer the personal explanation to the technical one.
As to your question about the reservoirs being higher, I would have to say,.. yeah,,.. but slightly. could that be the problem?
OK,.. I THINK I may have solved this. kind of.
SO after reading that excellent link by Rod... Thanks again,.. I understood that the master cylinder piston needed to "fully retract". I went outside and took a quick look. I immediately noticed how tight the rear MC piston was compared to the front ones. The rear wouldn't budge. It was stiff. I saw that the balance bar bolt, (exactly where the E is pointing) was wedged against some kind of nut on the pedal assembly. I used a screw driver to pop it off, and it came free. The brakes immediately released and the car was able to roll.
Now i have to figure out how to make sure this doesn't happen again...
Uhmmm on second thought,... I am not sure if the bolt was the issue. Looking at it again, in its relaxed state the balance bar nut doesn't really reach thar bolt on the pedal assembly. Something was sticking it. Something which came loose once I popped up the balance bar. Not sure what though.
Any ideas????
Rscocca
03-13-2011, 07:00 AM
Is it the same caliper that is locking up each time or both rear? If both rears do you have one or two flex lines?
If it is the same side each time check you flex lines if they are individual., If you let the caliper hang it may have torn the inside of the line and the rubber creates a flapper valve that when pressure is applied it will allow flow, when the pedal is released pressure cannot get back to master.
I have seen this manny many times and it will drive you crazy.
HTH
Bob S.
Is it the same caliper that is locking up each time or both rear? If both rears do you have one or two flex lines?
If it is the same side each time check you flex lines if they are individual., If you let the caliper hang it may have torn the inside of the line and the rubber creates a flapper valve that when pressure is applied it will allow flow, when the pedal is released pressure cannot get back to master.
I have seen this manny many times and it will drive you crazy.
HTH
Bob S.
G
Uhmm good suggestion. Not sure this is it though. tell you why. Once I popped up the balance bar of the master cylinder (rear) the problem completely went away. So the problem seems to be at the MC part of the car. Something, not sure what, was preventing the MC piston from coming back. May have been that bolt on the pedal assembly not sure. What is interesting is the point you just brought up. Why is it that only ONE rear brake was locking up? the passenger rear. as opposed to both.
In either case, I took her out today and the problem didn't come back. YET.....
Renegadezx
03-13-2011, 12:51 PM
How about a close up picture of this bolt and surrounding area?
oldguy668
03-13-2011, 12:56 PM
Check the pedal arm and see if it is hitting the 3/4" frame member. If it is, shorten both pushrods by screwing them into the pivot blocks a little. Then set the balance bar in the center.