I've got a set of 914-6 calipers that I'd like to rebuild, problem is that the pistons are frozen. They don't look too bad, but apparently they are bad enough to stick. I've tried pumping in 120psi compressed air into the bleader inlet, but it obviously did not work. Any suggestions would be very helpful.

Thanks!

got a grease gun? or can you hook up the caliper to the car and push the pedal?

soak em in PB blaster or some penetrating oil for a few days (heck, even simple green might work. youre rebuilding em anyway... so if it eats the seals... OH WELL)

then try the air again, if that fails, resort to hydraulic pressure. grease gun or brake line.... it will come out....

Are these front or rear???

Cause there is a differant technique for the rear that might work...

Twystd1

I almost always do it hydraulically using a bench pedal cluster and master cylinder. I only use air pressure on front calipers and only when they are known to move freely. Using high pressure air can cause a disaster. I have a few other techniques for the rears.

If they are in that bad shape, dare I suggest using Eric Shea's service. They will come back perfect ready for another thirty years. I can do the same in Canada, but do not have plating available, just paint. My /6 calipers will be going to Eric when I get a chance to cross the border.

I will need help removing the front and rear pistons. The whole set that I have has been sitting out of the car for about 15 years. What's the problem with pumping air through them? My next step was going to be to soak them in a bucket of simple green...

air compresses, fluid doesnt.....

i *think* what im trying to say is you have more mechanical advantage with fluid.....


if the air HASNT worked... try fluid.

The solution is just to send them to Eric Shea.

Then you can get other work done while waiting for your sexy calipers to be shipped back to you!!!

Dave's never short on good advice. I'd say for the fronts use fluid. I find that a bench devise is not the easiest thing to fabricate for a one time build.

I like the ease of a grease gun. You'll need air but it sounds like you've got that. A cheap Harbor gun is the ticket. Unscrew the nozzle and the threaded portion fits into your caliper. Put a clamp on the outside piston and push the inside one out.

Cover the hole with a large rubber washer (Lowe's) and a steel plate cut to fit into the opening and extend past the ears. Get a rubber washer that is the appropriate size to cover the piston opening. They have them. Have the steel plate extend into your vise to clamp the bottom with the mounting ears and use two smaller c-clamps on the top. Now push out the second one.

Now clean up the grease... sucks but, for calipers that have been sitting, that or a fluid bench machine is about the only way to get them out. Air compresses. Fluid doesn't.

For the rears it's completely different. You might be able to 'aid' the extraction with a fluid but you'll need to use the adjusters and PRAY. I've only seen a couple pistons that I couldn't get out but... you don't want your -6 calipers to be listed amongst that crowd.

The nice thing about 914 rears is the pistons screw out. I'd take that any day over grease... I have a couple of tricks gleaned from the 100-plus shitty rear calipers I've torn apart. If they don't come right away, send them in a Priority Mail Flat Rate box and we'll see what we can do.

One final simple one... if it's a nose cone piston, you can remove the clip and lock nut and insert a 4mm hex key and tap or press the piston out along with the adjuster. For the inner pistons it will be a little more challenging.

You've got my number if you run into any problems give me a buzz.

How much does Eric Shea charge for front caliper rebuild?

he asked for my left nut...


nah - its well worth the money.

Check the link just above you post. All you ever need to know.

Thanks Eric!!! I'll try your advice this weekend, if that doesn't work I'll send them to you.

Dan