Caliper Confusion
 

A couple of my calipers need kits but am having some difficulty determining what I have.
The fronts are aluminum, 1 piece. 3.5" bolt spacing
http://forums.pelicanparts.com/uploa...1547138138.jpg

Rears, two piece, ferrous metal, 3" bolt spacing;
http://forums.pelicanparts.com/uploa...1547138307.jpg

Muchos gracias!

Front are "S" and I believe the rear is an "M". Send them to PMB

+1 for PMB, excellent work.

Brake Calipers

Same calipers on my '74. I rebuilt the rear "M" calipers with no issues. The front "S" pistons were in bad shape so off to PMB they went. They did a great job and they came back looking like new.

I've noticed a considerable amount of drag trying to rotate the front rims and what seems like an unusual amount of pedal pressure to get the thing stopped.

And looks like a P.O. added the "S" calipers to my "T".

Thanks for the input!

The aluminum calipers may have corroded to the point where the steel pistons are sticking.

Fixing that S caliper probably needs a professional.

I've ordered kits, will try it myself first. I've rebuilt many calipers over the years. If the corrosion is extensive after I tear them down the calipers will go to the rebuilders.

Read on the PMB site to "hyperextend" the pistons, then compress them back to allow fluid to lube the seals. Going to try this first.

Check Hoses too
 

The hoses can have internal restriction after decades of use. If hoses are cracked, it may be time. Hoses were replaced and my dragging went away. IMHO: Get the good ATE fluid proper for your brake system model here at Pelican. There are several different ATE fluids so chose carefully and check the ATE web site.

PMB should be able get you going. I got my 3" Brembos from PMB years ago. :)

you can likely swap out the 20mm rotors to a 24mm set by getting a pair of 84-88 Carrera fronts. they bolt right up with the thicker rotor and require little to no master cylinder upgrade. when I did the "upgrade" the money I sold the S's for paid for the needing a rebuild caliper set, the wider rotors AND some new steel, open end lug nuts!


so you know, the pads are the same for the late S's you have, the SC & carrera front brake calipers that as I recall are called A calipers? or am I reporting fake news again. ?

I believe It was possible that your car came with S calipers as it was an option to order a T with S upgrades minus drive train

Could be. My COA lists options as Koni shocks instead of Boge, front spoiler and F&R sway bars.

When i changed the fluid I had the bleeder open and caliper was still really tight so I ruled out the hoses.

if the pistons are stuck that can give a hard pedal, like when the brakes fade.
replace the rubber lines while you are at it.

if you are doing them yourself I cant stress how well the power brake bleeder works from motive.
I just did the bakes on my 930 and the pedal is better than it has ever been, but I also put steel brake lines on.

I use motul 600/660 brake fluid.

Stuck
 

Outboard piston was stuck.
Was able to force the piston out using a homemade tool consisting of an old brake fitting and a grease fitting, pushed the piston out with the pressure of my grease gun.
Not too terribly corroded in the seal area, most of the corrosion was in the dust seal bore.
Ordered kits from Pelican yesterday, received them today. Great service!

http://forums.pelicanparts.com/uploa...1547243218.jpg

(Someone tell me how to index photos properly)

The upgrade to Koni would require the additional upgrade to S calipers as part of the package.