[r-mm]

I just pulled the calipers of my project GTV and found the driver side stamped ATE 250 and the passenger stamped ATE 254. Which is correct!? Does it matter that they're mismatched?

Also, the pistons/seals are looking pretty rough. What's my best bet? I'm not afraid of rebuilding them myself but wanna be a bit cautious since, well, they're the brakes. Local rebuild shop? Does it matter if they know Alfa/ATE? Reconditioned from IAP or similar?

 

[aralfa8589]

The front calipers from my 73 GTV have completely different numbers, and the numbers from my 89 Spider are different yet. The calipers are identical though. Centerline lists the same part for 69-74 and Spiders through 94, so I bet the numbers reflect different manufacturings of the same part.

 

[Peter]

Yeah, I've seen many different numbers too, so i wouldn't worry about it. Rebuilding is pretty simple, just get the pistons out and check for corrosion in the bores and on the pistons....very likely that you're OK. Don't split the calipers. The usual suppliers have rebuild kits, I think I got mine at Welcome to International Auto Parts last time. They are simply new seals and dust boots, easy to install. Don't toss the metal rings holding the dust boots, they don't come with the rebuild kits. Notice the orientation of the cutout in the piston when taking the pistons out/reassembling. Good luck!

 

[r-mm]

Thanks all...

I got one piston halfway out with the grease gun method. Man it takes a lot of grease! Need to go buy more. One thing thats not covered on the BB is how to get all the grease OUT of the caliper!?

What did you all do to clean up the exterior of the caliper?

 

[lotuseleven]

I popped the pistons out of my calipers using compressed air. you will get opinions that it's dangerous, but here's how i did it. I bought a threaded schraeder (tire inflation) valve and a metric adapter at the local Parker Store that fit perfectly in the caliper housing (maybe $4). it had an o-ring for good seal. leaving the caliper assembled, put a wrench between the pistons (where the pads usually go) so they don't push out too far. I used my bicycle pump, which is good to 140 psi and pumped up the caliper. get both pistons to pop (and they will "pop") keep your fingers out of the way. remember, the pistons are still loaded with compressed air until you bleed it off with the schraeder valve. you may need to push one side back in and hold it with a c-clamp to get the other side to pop loose, but eventually both sides will free up and then you can work both pistons out to re-build. best part is no mess (grease). I got rebuild kits from the guy who did the nice caliper rebuild thread (sorry I don't recall his company name), as he includes o-rings for joining the two halves. I figured not replacing them while rebuilding everything else in the braking system was asking for trouble.
my personal "Doh!" moment occured in bleeding the system. I put the calipers on the wrong sides, so the bleeders were on the bottom of the calipers. 3 days of pumping and I finally figured it out. swapped the calipers to the other sides and had the system bled in 30 minutes.
Stan

 

[Alfajay]

I just pulled the calipers of my project GTV and found the driver side stamped ATE 250 and the passenger stamped ATE 254. Which is correct!? Does it matter that they're mismatched?

You sure they're different? Your photo shows the outside face of one, and the inside of the other. Maybe the "250" and "254" numbers just indicate left and right.

One of the calipers in your picture looks like its outside surface has been ground flat. Probably a PO did this to provide clearance for an aftermarket wheel. That modification would concern me if the grinding extends very deep.

If you do have a generic rebuilder tackle the calipers, the fact that they came off an Alfa shouldn't be an issue. The ATE calipers used on Alfas are very similar to ones used on a variety of European cars.

 

[60sRacer]

it's a bit messy, but clean-up is easier if you fill your grease gun with brake fluid. Pistons come right out. Use one of those plastic oil pans to catch the fluid.

Robert

 

[r-mm]

60's racer - good call I'm going to try it tonight. Hope my lousy grease gun seals well enough to pump a liquid.

Alfajay - There is a distinct possibility you are right, I'm going to check (and be ashamed if you are right) tonight.

 

[r-mm]

Well, my grease gun will not hold a fluid (not made for bulk grease) so I just went with it grease.

On one caliper I got one piston out and the other is still frozen. Getting the frozen one free is a pita. Even when I clamp the free piston in place it seems to move (and stretch the clamp) before the frozen one budges. What to do?

On the other caliper I got one piston started, then clamped it and got the other started. Now they're both 3/4 way out but I don't know how to finish the job.

Any tricks? I presume the problem is the same with air.

What's the trick to removing/replacing the o-ring in the bore? From the parts diagram it looks like the bores are not removable.

Lotuseleven - what is the 'metric adaptor' you used? I was looking for something similar at home depot. You gave me the idea to use my mountain bike shock pump (good to 300psi) but I couldn't get the right adaptors.

 

[jantar]

Hi All, thanks for the thread its very timely as I'm about to do it

Well, my grease gun will not hold a fluid (not made for bulk grease) so I just went with it grease.

If you go the grease route what is the best way to clean up the calliper afterwards?

Lotuseleven - what is the 'metric adaptor' you used? I was looking for something similar at home depot. You gave me the idea to use my mountain bike shock pump (good to 300psi) but I couldn't get the right adaptors.

Lotuseleven - This sounds like a great idea, I'd be keen on finding out about this too.

Thanks

Chris

 

[PSk]

I just used my grease gun until the pistons actually fell out.

So how did I do the other half of the caliper?

Well I reinstalled the one piston that came out first and reassembled the caliper so the grease would be sealed in, and then used scraps of metal to hold the free piston in and then pushed with the grease gun and out came the other piston, or atleast so close to the end that it would fall out once the caliper was split again. Took a few reassemblies with grease everywhere ... but got there.
Pete