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[GregSC]

Hey guys, I recently purchased a couple of remanufactured brake calipers for my '77 (solid rotors in the front and drums in the back). I had to order calipers from two different companies because I couldn't find a company that had both available (the passenger side is really hard to find).

Anyway, when I got the calipers out of their boxes, I noticed that though the mounting frames, caliper frames, and caliper bodies were the same size as the ones from my car and identical to each other (I measured just to be sure), one of the pistons in the caliper didn't look quite right.

Come to find out, even though the piston bore is the same size as the other calipers, the piston surface that touches the brake pad is wider on one of the units that I just purchased. The original pistons (and one of the pistons that I just purchased) have about a 44mm surface that touches the brake pad and then enlarges to 48mm inside the bore. But this one caliper has a 48mm piston all the way through.

My question is this, will I be able to use these two remanufactured calipers even though the contact surface of one piston is 44mm (passenger's side) and the other is 48mm (driver's side) and will this cause any problems in braking effectiveness or brake balance? I would think since both calipers have the same bore, caliper body, and frame size I will be okay, but this is my first time working on the brakes on this car and I need a little reassurance.

Thanks for the help.
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1981 931

[musicalannette]

hi,

If i understand you corretly, the piston diameter is the same, and on one piston the size reduces where it touhes the pad. They do this to try and stop heat transfer into the piston and thus the fluid.

If the bit the brake fluid pushes on is the same diameter (and thus has the same area) then they will both be balanced. Problems occur when you don't have the same area.

If your doind this and the pipes are all ok, I would consider replacing the two rear wheel cylinders while you at it (they cost next to nothing) and filling the system with automec fluid, then you will have new brakes and wont have to touch the brakes again for fluid changes! I think if you look at beetle '67 on Indipendent Rear Suspension (I.R.S.) brakes and wheel bearings, uprights at the front and torsion bar suspension at the rear, they should be the same if you need to order any bits. Usually cheaper too! Beetle bits are very easy to come by.

Hope this helps.
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I KNEW white wall tyres were invented by Americans .....just not at Boeing.... to be fitted on the 737.....

[Fifty50Plus]

Ahhh...9XXGirl is back
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1979 924 NA race car H-Prod SCCA
1982 924 NA race car - Sold
1981 924 Turbo sold
1982 924 Turbo sold
1972 911 E race car - traded for Cayenne Diesel
1975 914 1.8 Building for H-Prod SCCA