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Rear caliper hand brake holder jammed
Posted: Thu Nov 21, 2013 8:07 am
by rjkoop
I'm rebuilding the rear calipers. Everything's cleaned up and ready for rebuild kit and reassembly. One thing I noticed is that the holder that the parking brake cable attaches to on one side spins freely but the other one is jammed/really stuck.
Here's a link to similar calipers (I couldn't find my camera to take a picture) with the piece circled.
I can turn it with a screwdriver inserted into it but it doesn't turn freely like the other caliper. Can this piece be removed? I tried WD-40 / liquid wrench but doesn't seem to loosen it much.
Re: Rear caliper hand brake holder jammed
Posted: Thu Nov 21, 2013 11:27 am
by Meistro
Mine were a little tight, so I placed the main body in a vice and used some break free juice from WD-40 and a screwdriver. It took a little while of wiggling back and forth but it eventually worked loose.
Gene
Re: Rear caliper hand brake holder jammed
Posted: Sun Dec 01, 2013 9:06 pm
by rjkoop
Meistro wrote:Mine were a little tight, so I placed the main body in a vice and used some break free juice from WD-40 and a screwdriver. It took a little while of wiggling back and forth but it eventually worked loose.
Gene
It's amazing what time and a little oil / WD-40 will do...
Holder now moves fine.
I'm having a little trouble getting the piston to go back in. I cleaned out the seal groove with a brass dremel bit, cleaned the piston with with scotch bright pad, put the seal back in and lubed everything up with brake fluid and was thinking the piston should be able to be pushed back in if I put it in straight. I don't have the plunger side in yet so I don't have to screw the piston into it yet. But the piston seems to get stuck on the seal and won't go any further even with gentle encouragement with a clamp. Is there a trick or should I take the seal out again, clean the groove better and retry?
Re: Rear caliper hand brake holder jammed
Posted: Sun Dec 01, 2013 10:22 pm
by BEEK
install the handbrake side first, then screw the piston in
Re: Rear caliper hand brake holder jammed
Posted: Mon Dec 02, 2013 7:47 am
by rjkoop
BEEK wrote:install the handbrake side first, then screw the piston in
Sounds good. I just wanted to be sure that the seal wouldn't bind when the piston is pushed/screwed into the caliper. I guess as long as the seal seat is clean and it's lubed up with brake fluid it should be ok. I guess the screwing the piston in would help work it in easier as well.
Re: Rear caliper hand brake holder jammed
Posted: Mon Dec 02, 2013 3:13 pm
by azruss
The piston doesn't retract to flush with the casting. It will only retract to flush with the dust seal
Re: Rear caliper hand brake holder jammed
Posted: Mon Dec 02, 2013 4:59 pm
by rjkoop
azruss wrote:The piston doesn't retract to flush with the casting. It will only retract to flush with the dust seal
K. Thanks. Good information. And wedge for the hand brake mechanism... does the fat part of the wedge go down towards the plunger / caliper body? I should have taken more pictures but who knows if it was rebuild before and possibly not done correctly. I even noticed that the clip was missing off one of the ends of the hand brake mechanism.
I think when I get it back together 100% I'm ensure the mechanism works well and doesn't bind. Also going to have to trim the edges off my clamp to allow it to fit on the end of the plunger to push it in to install the hand brake wedge. Does the clamp sit on the longest edge of the end of the plunger and still allow room to slide in the lever and wedge piece?
Re: Rear caliper hand brake holder jammed
Posted: Wed Dec 04, 2013 7:59 pm
by rjkoop
So one of the rear caliper rebuilds went perfectly. Action on the hand brake lever and plunger is perfect and springs back fine. On the other one it wouldn't rebound without a bit of help and it looks like one of the sleeves that the hand brake lever slides into broke when I reinserted the lever. Any idea where I could get 1 of these?
I think it's something like this.
http://www.fiatplus.com/rear-caliper-br ... 06686.html
Re: Rear caliper hand brake holder jammed
Posted: Fri Dec 06, 2013 8:00 am
by rjkoop
Finally got 1 of the rear calipers back together. I hope I never have to do this job again. Biggest thing was ensuring area under the piston bore seal was clean. Otherwise when you try to insert / screw-in the piston it won't go far enough to catch the thread on the plunger. I'm going to take a few pictures and maybe do a write up for the benefit of others. But a few tips.
- take pictures as you disassemble - I didn't and you kind of have to figure out the mechanism when reassembling
- you must compress the plunger to allow the insertion of the hand brake lever
- you must cut a C clamp to allow it to sit on the top of the plunger to compress it.
- the end of the C clamp should sit on the longer piece on the plunger to allow you to slide in the wedge and the lever
- you'll be able to slide in the wedge and the lever a bit, remove the C clamp and then continue to push it in
- the wedge sits fat side towards the plunger and skinny side towards the lever
- really clean out the piston bore under where the seal will be inserted - otherwise the piston won't go back in (use a small dremel brass wheel for this)
- use a long file to screw in the piston - once it catches it goes it fairly easily (at least for me)
- coat seals and everything in the piston bore in brake fluid
The other caliper I'm having trouble screwing in the piston. But it's definitely the seal issue because when I take the seal out (just to try it) it screws in fine. More work with the dremel brass wire wheel in the groove should fix the issue.
Re: Rear caliper hand brake holder jammed
Posted: Fri Dec 06, 2013 9:30 am
by 4uall
Nice job, looking forward to the pics
Re: Rear caliper hand brake holder jammed
Posted: Sun Dec 29, 2013 1:18 pm
by rjkoop
Not had much time to work on these lately but now they are finally done. I decided to go with red caliper paint.
Phew! Next time I'll just buy the rebuilt ones.
And painted these while I was in the area... I find it really tough to leave stuff alone when everything is apart!
Might have to sand down the contact points though...
Re: Rear caliper hand brake holder jammed
Posted: Sun Dec 29, 2013 9:06 pm
by redcars
Yes please sand down the contract areas! We do not want to hear about you loosing a rear wheel.
Re: Rear caliper hand brake holder jammed
Posted: Mon Dec 30, 2013 6:46 am
by rjkoop
redcars wrote:Yes please sand down the contract areas! We do not want to hear about you loosing a rear wheel.
And for contact points is this essentially where any surface touches another? I POR-15ed the brake shields and then painted everything else including the wheel spacers, caliper mounting brackets and caliper brackets. The only thing I didn't paint was the sliding surfaces of the caliper brackets. Hopefully I don't have to sand 90% of what I just painted.
And to sand the paint off should I use sanding paper or just a quick pass with a grinder?
Re: Rear caliper hand brake holder jammed
Posted: Mon Dec 30, 2013 11:34 am
by redcars
I would only really worry about where the wheel bolts on.