[mstrjon32]

Thanks for the explanation. I should have tested the service brake while I had the car on the machine, it would have been interesting to see if the pressure imbalance was evident for both the service brake and parking brake, but I guess it must be!

I will take the car back in on Tuesday, compress the pistons, and see how it goes.

 

[TomatoSoup]

I don't fully understand how this will fix the parking brake. Can someone maybe explain what compressing the piston and reassembling everything will do?

Thanks for the clarity.

Read this - both pages. This is about a Bronco, but using GM rear discs and matches exactly how our brakes work: Classic Broncos .com - Tech: Rear Disc Brakes using Cadillac/GM Calipers - 66-77 Early Ford Bronco

 

[chickenwire]

Ditto - do both sides. Can't hurt - can only help. (And you'll notice better braking on the road!)

 

[mstrjon32]

Thanks for the support, guys, and for the link TomatoSoup, very interesting.

I took the car to the shop today and compressed the pistons on both sides. Then I pumped the footbrake 8-10 times, then the handbrake. The e-brake was holding well and the car had no problems when I took it for another inspection. In addition, the footbrake seems to be much firmer and braking feels better overall. The brake was so tight after this service that I had to loosen up the nut on the handbrake under the console.

I used a tool that connected to compressed air to help with compressing the pistons. It has a piston of it's own, connected to a handle, and you can place it inside the caliper and use the compressed air to compress the piston as you turn it with the handle. It made short work of the job.

 

[mstrjon32]

For reference, the tool I used was similar to this one:

 

[TomatoSoup]

Wow! Haven't seen that one before. I use a similar thing but as you screw it it pushes and turns. Not quite so fancy as yours

Similar to:

 

[strong05]

This worked great for me! Just used needle noise pliers (in lieu of the fancy tool). Also made my brakes work a lot better as I suspect the rear brakes were either inop or close to it. Mods please make this a sticky!

 

[Canuck Sol]

My parking brake started slipping last fall. This spring I tried the back and forth trick to get drum brakes to snug. but it did not work. I went to the Poconos for NASSM this summer and after three hard runs my parking brake is now holding again.

From what I see, if your parking brake does not hold, you are not having enough fun :jester:.

 

[TomatoSoup]

My parking brake started slipping last fall. This spring I tried the back and forth trick to get drum brakes to snug. [...]

Ain't no drum brakes in our cars!

I probably posted this link earlier in this thread, but just in case, our rear brakes are just like these: Classic Broncos .com - Tech: Rear Disc Brakes using Cadillac/GM Calipers - 66-77 Early Ford Bronco

 

[Canuck Sol]

Ain't no drum brakes in our cars!

Oh, so that's why I see calipers and rotors all around, duh.

 

[TomatoSoup]

Oh, so that's why I see calipers and rotors all around, duh.

I assumed you were talking about drums for the handbrake. Some cars with rear discs have inner drums that are just for the E-brake. But not ours.

 

[Canuck Sol]

I assumed you were talking about drums for the handbrake. Some cars with rear discs have inner drums that are just for the E-brake. But not ours.

I just mentioned I tried a trick that works for drum brakes and it did not work, I didn't say ours had them. Your link states using the ebrake adjusts them but mine still got out of adjustment even though I use it every single time I park.

What I did find is that after three days of aggressive driving the ebrake now holds again on significant slopes.

I would suggest if you have this problem, you just go out on some back roads and do some hard braking.

Or you could try the other labour intensive options provided.

 

[Orange one]

Thanks for the spot on instructions! Worked great.
BTW, the needle nose plyers can be substituted for the special caliper piston tool.

 

[MAKsys]

My parking brake hasn't worked in YEARS (at least 5 years, maybe more). Here in Michigan (at least in my part) a few degrees of grade in a driveway is about all I see). Anyways, with 108k miles on the rears without any service, I assumed it must be time for new pads. Pulled off both wheels, and the pads have almost no wear. I decided not to fool around with trying to compress and turn these calipers by hand, so I opted for the $40 kit at Harbor Freight - it literally took more time to jack up the car and pull the wheels, than it did to pull the calipers, use the tool to run the cylinders all the way in, and put it all back together.

If you think you have this problem, do yourself a huge favor, spend the 40 bucks and get the right tool for the job. Piece of cake.

 

[chickenwire]

MAK - did you notice an increase in braking? I did immediately after I made this adjustment. It surprised me because obviously most of (or ALL of in your case!) the braking is done by the fronts.

 

[MAKsys]

MAK - did you notice an increase in braking?

Definitely - and using a lot less pedal.

 

[NoBrakes]

Background: Haven't had a parking brake since the GMC dealer replaced the differential. I've taken the car to three different shops and had the calipers replaced twice and still don't have a working parking brake. It just won't hold on any type of incline. Looks like I'm going to have to fix it myself.

I read through everyone's comments here and thank you for your advice I'm going to try this repair this weekend. When the battery shorts out the electronics and a piece of road debris cuts the hydraulic lines I want something mechanical that I can rely to stop the wheels from turning and I just don't have that now.

True story - I was in my '65 VW Beetle approaching the railroad tracks, stepped on the brakes and nothing; the lines had rusted through. I grabbed the E-brake handle like my life depended on it. The car came to screeching, sideways halt just as the train went by.