Replacing calipers...how long should it take?
 

I have my new calipers in my garage for my 78. I will be replacing all 4 very soon at the Auto Hobby shop on base. I will NOT replace the soft hoses as I did that last month. I am pretty good with a wrench but have not done this type of job before. Can I do it in a day? Four hours? The reason I am asking is that they will not allow me to leave my car overnight and I do not want to start a job at noon that I can not complete in 5 hours. Thanks for any help.
Bob

If you are just doing calipers and not messing with wheel bearings on front etc...you should be able to do each wheel in 15 minutes or so once the wheel is off. Two bolts hold them on and you unhook the lines and swap them out. Bleeding is what it is..sometimes fast..sometimes slow..so I'd allow extra time...but for sure it's a nice job that can be done in an easy day.


JIM

You can probably replace the calipers in four hours; as you probably already know most if not all military auto hobby shops have a sort of roving on-site assistant to help you with any questions or issues, and rolling in there with a C3 Vette will only serve to attract their attention even more. The big issue when doing almost anything related to the brakes on these cars is the diabolical process of getting all the air out of them...if your particular hobby shop has a pressure bleeder available by all means use it. Attempting to bleed the air out of four new calipers could become a long, frustrating exercise otherwise.

If you have the right tools, floor jack (or lift), it should be about a 3-4 hours job to replace the calipers if nothing goes wrong. You will likely need a good sized breaker bar for the main caliper bolts. Also, I'm thinking those bolts are cap screws which take a large Allen wrench or Torx head. Just make sure you determine what socket is needed to remove them and that the shop has the one you need...or pick it up yourself before you go. Other than that, your job shouldn't be too tough.

P.S. I'm assuming that you are installing new pads at the same time. Don't forget the packets of "anti-squeak" goo that get put on the back of the pads. All the auto parts stores sell them.

You also will need to bleed the brake system. You'll need a quart of brake fluid (same type as you already have), a glass pop/beer bottle, and a length of plastic tubing. If you don't have experience in bleeding the brake system, do some internet reading on the 'how to's' so you can be prepared. Work from the wheel nearest the master cylinder to the one farthest away (LF, RF, LR, RR); the rear calipers have 2 bleeders on them. You might need to drive it around the base a bit after you do the bleeding. If it feels spongy after the ride, do it again. Driving the car can free up some trapped air in the system. The brake bleeding process can take from a couple hours (normal with no problems) to several days if trouble is encountered. Have the bleeding "plan" clearly established and it will go quicker. :flag:

The bolts holding calipers on are just normal stuff. No biggee.

JIM

Since your replacing all four calipers, I suggest you gravity bleed them first when your done with each. To do this, make sure the master cylinder is full, open the bleeders (2 on each caliper) and wait untill you get brake fluid coming out of them. As you see fluid coming out of each bleeder, close it. It's important to make sure the master cylinder stays full, otherwise you'll be pulling air back into the system. Once you've gotten brake fluid out of and closed each bleeder of all four calipers, you can use a pressure bleeder or the "pump and hold" method to finish it off. Start with the inside bleeder on the rear right, then the outside bleeder, then the left rear, right front and left front caliper.

How things have changed since my days at the Naval Air Station's Hobby Shop. In the late 60's, they charged $1 a day storage if you needed to take up a bay overnight.

Replacing 4 calipers in 5 hours is quite do-able. And you don't need to have the brakes bled perfectly, just enough to stop on the way home or back to the barracks, whatever your case may be. You can always finish the next day.

Or, if you have problems with rusted bolts/fittings concentrate on either the fronts only or the rears only--you have a dual master cylinder, so each end really acts as a separate system.

The big variable here would be whether the hard-line to the front rubber lines are able to be removed easily, or if the steel lines are rusty and would break off. Since you've replaced them already up front, you should have no problem. I found it tricky to get the pads in; a stiff broad (~4" wide) spackle-blade worked for me. Put the blade down against the pistons, push the pad against the steel to push in the pistons, and then the pad can be slid down into place.

There are no Allen or Torx bolts on C3 Corvette calipers. You will need a thin wall 5/8 deep well socket, and hopefully they will have an air wrench handy.

Forget the goop on the back of the pads. That is death for these calipers. It causes the piston to crank sideways every time the brakes are applied especially going forward and back, and it stresses the pistons and seals. They will leak prematurely.

Thanks guys....I have the new brake pads as well and each box contains the "goo". How/when is the best time to apply the "goo"?
Thanks

Don't.

I never used the goo, but last week I "cured" a squeak in the right rear brake with an aftermarket little plastic tube.

As far as getting the job done in a day, as someone already pointed out, it really depends on what, if anything, goes wrong. When I did the rear rotors/calipers/pads on my old car in an apartment garage with no power or light, the bolts were rusty, crusty, old and heat-soaked on so bad, it took me a few days with liquid wrench to get one of them off. Now that I have my own garage, with electrical power, an air compressor, and impact tools, when I took the rear calipers off last year, the bolts popped right off with a regular socket drive. :willy:

my recommendation is first check if the MWR hobby shop has a 3/8" line wrench so you can prevent rounding off your hard lines.. if they don't just pick one up at sears... if you do junk a hard line you may have to wait a few days to get a new one.. I did this when I was in Hawaii (I was working in my home garage on base rather than the hobby shop) and when I rounded off the hard lines in the rear it took me a week to get a replacement...

Its real easy if you have the right tools and a little time.. I've done this on 2 C3's my first (sold to a buddy) and my current.. the first time took me about a week (parts) really only about 6 hours of work time.. and the second took about 4 hours.

If you're not sure of your capabilities why not PLAN on doing just the front, start to finish including bleeding?

If all goes well move on to the rear.

Bleeding the rears won't affect the front bleeding.

:iagree: Ask me how I know....... Good news was that I replaced my calipers and brake pads in my home garage so when I broke one of the hard lines I was able to get in my other car and drive to the parts store to buy another line.:ack: Good Luck w/your job. It was pretty easy all things considered.....

SHOULD not take long, however factor in frozen brake line nuts, the hassle of bleeding the brakes and you can spend a lot more time than planned .

I was a dependent in the 70s and used the auto hobby shop a lot. I clearly remember the following line spoken over the shop PA every bloody night "Clean up time, Clean up time, turn in your tools, let's go home.... this means you too John ! ! "

The idea of the helpful roving auto hobby shop "helper" is an interesting one. That occasionally happened, but I was more used to :

"Hey guys, come look at the mess John made with THIS ...." followed by insults about my mental capacity, my mechanical skills , my ancestors, the length of my hair.....

You get the idea...

It was a fun place, I learned a lot.

John

One tip on replacing the calipers... find a 1/2" drive socket that is as long as the width of the rotor., plus a hair. I think my C'man 5/8" socket is a perfect fit +1/16". Wedge the socket in between the pads. Now fit the caliper assy over the rotor...as you lower it around the rotor, it'll push out the socket and you're good to go.

John

FWIW, I always tackle brake caliper/pad type work in axle sets when working on a vehicle that's in service. That way if it takes longer than expected or duty calls you have a good stopping point built into the middle of the project. More than once has this strategy paid off. My $.02

He's not just changing pads (requiring the piston to be pushed back). He's replacing the calipers too. The piston will be in the full-in position already. Easy to stick new pads in there when its an unused caliper.

I highly suggest PB Blaster to the caliper bolts for a few days with reapplications prior to doing the brake job. I live in a dry climate but it took me days to get mine loosened up to where I could do the work. Once bolts were loose it seemed to go pretty quickly.