Brake questions

#1

Swapped out my front pads today. Is really a pain in the ass compared to a Porsche. Ended up with some questions for my community of mentors.

  1. What are the little springs for on the pad? It was hard to tell if they were supposed to poke thru the hole in the pad carrier assembly (a phrase I just made up) of if they were supposed to be compressed flat inside the pad carrier assembly.

  2. What is the trick to compressing the piston back into it’s cylinder? That was a pain in the ass.

  3. One of my piston dust covers is damaged. My E30 book recommended buying a new caliper because it assumed that a damaged dust cover meant a damaged piston/cylinder. You agree that I need a new caliper assembly? I can’t just go buy another piston dust cover?

Thanks guys, -S

#2

Trust me, it gets easier. The springs on the top of the pads are supposed to compress against the inside of the caliper. If they poke through the openings then they need to be repositioned. This can be a PITA sometimes. I believe they are intended to keep the pads tight within the calipers.

The easiest way that I have found to compress the piston into the caliper is to remove the brake reservoir cap and use a large (6 inch) C-clamp to work it back in.

If you do not know if or when your calipers were rebuilt last its probably a good idea to do it now. This does not mean that you need to buy new calipers but you can buy a rebuild kit and do it yourself. They include the dust seal and inner seal for the piston. They run about $25 for the fronts. Again, the first time you do this its a pain but it gets easier.

#3

C clamp works OK but the 10.00 tool from autozone works pretty good too for the piston.

Rebuild kits for the calipers are available.

#4

Thanks for the tips on compressing the piston.

I looked up caliper rebuild kits at Pelican. They want to know if I have ATE or Girling calipers. How do I tell?

#5

The calipers should be marked, in my experience. ATE has their logo cast into it, Girling usually has a stylizied ‘G’. If I had to guess (and I do), I’d say the ATE are the most common.

You don’t need a fancy tool to compress the piston. Get yourself a super-size pair of Channelock pliers. I mean, really big ones. If they can fit around the cam pulley, you got the right size. You can squeeze the piston back in with the leverage they give you very easily. Just make sure you have the tool squarely on the piston so you’re not forcing it at an angle. You may have to reposition a bit as it goes in, depending on how far out it was. This is a tool I use for innumerable things and pays for itself manyfold.

#6

Ate’s require a 7mm allen to remove, Girlings require a 14mm and a 15 open end wrench/sockets (if my memory serves me right). I personally prefer the Ate’s after having and maintaining both. The Ate’s also can use the brass guide bushings, which are SpecE30 illegal but can save you cash before you start racing. On that note, replace the guide bushings with OE rubber ones as well as the rebuild kit (inner seal and dust boot).

Regarding the tool, I bought the $10 tool and then modded it…

It just helps push that tired old intolerant piston back into place squarely. I used to be a channel lock guy…

I believe you can buy a tool similar to how I modded the cheap one. This winter’s project will involve welding a handle on since the plastic one strips.

#7

Craig, I’ve got that same tool (unmodified) and have never been able to get it to work. I guess that’s why you modified yours.

#8

7mm eh? That tells me that I have the ATE, thx.

Re. the tool. Bought it this morning on the Internet. Sadly, I didn’t think to look to see if they were selling the Geiger modified version that actually works.

#9

I have used channel locks and the c-clamp, but the little autozone tool is def the easiest for me. To get the piston to go in square I just use a worn out brake pad - the steel backing plate fits perfectly.

#10

Ken Neuhoff wrote:

[quote]Craig, I’ve got that same tool (unmodified) and have never been able to get it to work. I guess that’s why you modified yours.[/quote]What didn’t work, Ken…Mine works great???

#11

AJ Goldsmith wrote:

[quote]I have used channel locks and the c-clamp, but the little autozone tool is def the easiest for me. To get the piston to go in square I just use a worn out brake pad - the steel backing plate fits perfectly.[/quote]you have to put the end of the threaded shaft inside the piston, not on the rim that touches the pad.

#12

It must have been me. I couldn’t fit the tool into the caliper. As I recall the metal plate was hitting the caliper and wouldn’t go in. I’ll try it again if I can find the thing.

#13

AJ Goldsmith wrote:

Well played!