911tracker85

Dang... initially posted this to the end of my other thread.


in the process of trying to rebuild a rear caliper for a 76 2.0 for a friend.

one from the car was badly corroded/rusted and frozen. the guy got a used one pictured below that appears decent, along with a rebuild kit.

got a couple 914 books, but not the WSMs. when starting to work on the used caliper found this little widget in a recess on the side where the emergency brake actuator is. no bolt holding it in, just came out using a small pic. looking down inside I see a small opening on the side where the emergency brake actuator is connected. tried pulling on the lever and it moved but could not see anything acting inside the hole/resess.

the old one from the car does not have a bolt or anything in the recess.

started reading about these brakes, and did find when turning the bolt on the other side of the caliper the piston moves in and out as described for adjusting clearance. need to read more, but.

anyone know what this is? is it just missing a bolt or something?

thanks for the advice.

Matt Romanowski

The other side we can't see should be a 4 (?) mm hex. It just sits in that bore and is what you use to adjust the venting clearance on the rear pistons. There should be a cap for that bore. The original was a female hex that would strip real easy. Most have been replaced with a plug that has a ~8mm male hex on it.

Matt Romanowski

http://www.pelicanparts.com/914/Part...ke_cal_big.htm

What you have is #20. You need to buy 19. Here it is http://www.automotion.com/brake-cali...1970-1976.html

If you buy rebuild kits, make sure they have all the peices for the adjusters. Get them from Paragon and ask Jason - he'll know what you need.

911tracker85

thanks for the reply. I have rebuilt calipers on older 911s and motorcycles.

clearly these on the 914 are more complicated. I suspected so when I saw all the little parts in the rebuild kit.

skl

I tried to rebuild the rears on my '73 and after getting rather frustrated, bought rebuilt ones that look better than new from PMB (Eric Shea) for not an unreasonable price.
You might try that too... I might even get "new" front ones to save the frustration there as well...

911tracker85

and everybody kept saying 914s are less complicated than carreras and 928S.

it may be the used caliper works, need to check before I pursue a rebuilt. I have been convinced to drop the idea of rebuilding. I have a lot more valuable ways to spend my time.

Matt Romanowski

If someone else can rebuild them you can too. PM me if you want some more info on rebuilt units.

911tracker85

have been reading about these rear brakes on the pelican tech.

on the used caliper that is off the car, there is just a gaping hole on the inside/emergency brake side after removing the 'resetting shaft'. as Matt noted, it is missing the 'closing screw'. see my pic at beginning of this thread.

in the tech article explaining replacing pads and adjusting these rear calipers, are they referring to turning the 'resetting shaft' to adjust the inside piston? the article makes it sound like there is a similar hex screw in that hole that you turn to also set that clearance. no mention of that little 'resetting shaft' I see in the link from Matt showing the caliper cutaway view in the article.

I am beginning to reconsider rebuilding. a bit of a PITA compared to other calipers, but interesting.

note to self, you really need to stop using the banging head emoticon. remember ... you love wrenching on Porsches ...

Matt Romanowski

The little star shaft you pulled out should have a hex on one end. Stick it in the hole and then turn it with the hex to move the piston in. The outside one is easier as you can see it when you remove the cover.

911tracker85

thanks, what I suspected. going to give it a try this weekend.

911tracker85

I have started rebuilding a used caliper the guy got as the original is in pretty bad shape. had put air pressure to the caliper and could see leaking from between the caliper halves.

good articles on Pelican about rebuilding, but no pics. and I think I will not bother pulling the ebrake arm. that part is outside the brake fluid area and sounds like more of a PITA than necessary. drilling holes in a plug on the side opposite the ebrake arm, and then find a 25mm freeze plug to hammer back in.

so here are pics of the inside/ebrake side of the caliper apart. the outside was easy, the screw pushed the piston all the way out.

not sure why but the adjuster screw would not push the inside piston out. pulled the ebrake lever and it moved the piston out some. so I had to pull out the piston and it came off the 'COLLET' (what the pelican article calls the part that pressed inside the piston for the screw to act on.) so my pics show that out of the piston and partially disassembled.

will have to press the collet back into the piston before reassembly.

now that I have it apart and can see/understand how this works, not too complicated. but as with rebuilding most calipers, the dust boots had torn and the outer rim of the piston hole had enough corrosion that you have to work at getting the pistons out.