rear brakes on a 78 - frozen pistons
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seabeelt
- Patron 2019
- Posts: 1614
- Joined: Tue Feb 19, 2008 4:22 pm
- Your car is a: Fiat Spider - 1971 BS1
- Location: Tiverton, RI
Re: rear brakes on a 78 - frozen pistons
There should be no dragging
Michael and Deborah Williamson
1971 Spider -Tropie’ - w screaming IDFs
1971 Spider - Vesper -scrapped
1979 Spider - Seraphina - our son's car now sold
1972 Spider - Tortellini- our son's current
1971 Spider -Tropie’ - w screaming IDFs
1971 Spider - Vesper -scrapped
1979 Spider - Seraphina - our son's car now sold
1972 Spider - Tortellini- our son's current
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DieselSpider
- Posts: 2130
- Joined: Wed Dec 24, 2014 10:21 pm
- Your car is a: 1978 124 Spider with Isuzu Turbo Diesel
Re: rear brakes on a 78 - frozen pistons
While there should be no dragging there may be exceptions as some pads may be a little over spec on their thickness. If you did not disassemble the calipers and clean out the bores there may be some corrosion preventing the parking brake actuator from retracting all the way. After a few heavy brake applications they may rub but should not drag.
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timspider
Re: rear brakes on a 78 - frozen pistons
starting over again on the rear brakes. they ran a little hot and then seemed to settle in after a few test drives, but both back brakes have run intermittently hot for the last couple thousand miles.
Last week started to hear/feel something metallic that didn't sit right. Have not heard that squeal clip from the rears and didnt' even consider that these pads could already be an issue.
Checked the rear brakes just to get a look and the pads on both sides are worn to the metal. One side the new rotor is scored from the metal backing of the pad- so swapped an old, but good condition rotor back on that side and ordered a new set of pads from O'Reilly's which are due in tomorrow morning.
So I'm back to screwing these pistons back in already and while I've gotten both sides to turn fairly freely (slowly-but freely), they do not appear to be retracting.
I've read through the thread again- reminded me of some good stuff
Perhaps cracking a bleeder might help?
If I could find the bleeder screw on the rear caliper. It's not where my trusty manual says it should be.
I don't see it anywhere on the housing of the caliper. Spent enough hours staring at this.
Bleed them to assist in retracting a piston?
If so, how?
thank you
Last week started to hear/feel something metallic that didn't sit right. Have not heard that squeal clip from the rears and didnt' even consider that these pads could already be an issue.
Checked the rear brakes just to get a look and the pads on both sides are worn to the metal. One side the new rotor is scored from the metal backing of the pad- so swapped an old, but good condition rotor back on that side and ordered a new set of pads from O'Reilly's which are due in tomorrow morning.
So I'm back to screwing these pistons back in already and while I've gotten both sides to turn fairly freely (slowly-but freely), they do not appear to be retracting.
I've read through the thread again- reminded me of some good stuff
Perhaps cracking a bleeder might help?
If I could find the bleeder screw on the rear caliper. It's not where my trusty manual says it should be.
I don't see it anywhere on the housing of the caliper. Spent enough hours staring at this.
Bleed them to assist in retracting a piston?
If so, how?
thank you
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timspider
Re: rear brakes on a 78 - frozen pistons
oh, and important to add that I had both pistons screwed in with the small scored area pointing down- not up like the manual says.
I was so busy making sure the groove was sideways to accept the notch in the pad, I didn't check to the top and bottom orientation. That's the best excuse I got.
I'm hoping that is what was screwed up with these- that and the fact that they feel like they need to be cleaned and lubricated better.
Really hoping to save these and not replace them
I was so busy making sure the groove was sideways to accept the notch in the pad, I didn't check to the top and bottom orientation. That's the best excuse I got.
I'm hoping that is what was screwed up with these- that and the fact that they feel like they need to be cleaned and lubricated better.
Really hoping to save these and not replace them
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wizard124
- Posts: 752
- Joined: Mon Oct 29, 2012 9:27 pm
- Your car is a: 1980 124 spider FI
- Location: Sheridan, WY exSan Rafael, CA
Re: rear brakes on a 78 - frozen pistons
I found all 4 brakes to be tight and drag abit after installing new pads. Mine seemed to wear in. Some squealing from the fronts when I back out if the driveway.
Mine brake better after some miles and use.
Mine brake better after some miles and use.
'80 spider FI, SnugTop hardtop
http://s940.photobucket.com/user/a7ewiz ... t=3&page=1
http://s940.photobucket.com/user/a7ewiz ... t=3&page=1
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timspider
Re: rear brakes on a 78 - frozen pistons
update: cracked open a little bolt head that ended up being the bleeder and that allowed me to get the pistons screwed in, so both sides are ready for the new pads, which of course, did not come this morning as promised. Now it's Wednesday morning.
I get why many of us build up a personal inventory of regular use items now. Totally get it.
Front and rear pads will be added to normal stock now.
I get why many of us build up a personal inventory of regular use items now. Totally get it.
Front and rear pads will be added to normal stock now.
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timspider
Re: rear brakes on a 78 - frozen pistons
Another update as I have not cleared this issue yet. Lots of other issues sorted out and car is running very well, but back brakes are both running hot.
The first ride literally had the left rear wheel smoking when I stopped. Then the other side would get hot and they both threw off black pad dust that would coat the wheels each time out.
Took them apart again- found and replaced a couple suspect pad springs and got those little slide pieces sanded down to bare metal and very clean before greasing for re installation.
Then the over heating was intermittent. I would drive 20 miles and both sides just a little warm- normal dust, then the next day, one side or the other would run hot- they never ran smokey hot again- but hot to the touch and sometimes excessive dust again.
So my question.
It seems as though fluid will not push back- only way I found to retract pistons was to crack the bleeder open- they would not budge before I did that. I could screw them but they would not go down.
The top was off the reservoir, so it seems something upline from that is providing back pressure- like a check valve kind of thing- maybe the compensator is blocking back flow?
I'm grasping at straws I know. Just throwing thoughts out there as this is my first run through the brake system.
Any ideas are appreciated
The first ride literally had the left rear wheel smoking when I stopped. Then the other side would get hot and they both threw off black pad dust that would coat the wheels each time out.
Took them apart again- found and replaced a couple suspect pad springs and got those little slide pieces sanded down to bare metal and very clean before greasing for re installation.
Then the over heating was intermittent. I would drive 20 miles and both sides just a little warm- normal dust, then the next day, one side or the other would run hot- they never ran smokey hot again- but hot to the touch and sometimes excessive dust again.
So my question.
It seems as though fluid will not push back- only way I found to retract pistons was to crack the bleeder open- they would not budge before I did that. I could screw them but they would not go down.
The top was off the reservoir, so it seems something upline from that is providing back pressure- like a check valve kind of thing- maybe the compensator is blocking back flow?
I'm grasping at straws I know. Just throwing thoughts out there as this is my first run through the brake system.
Any ideas are appreciated