 |
|
Hey guys, is there a good trick for getting the front caliper dust boot on? I got the rears done no sweat but have been wrestling with the front calipers for a while now. If I start out with the boot on the piston then I can’t get the seating ring in the caliper, and if I start with the boot seated in the caliper then I can’t seem to get the piston to slide through the opening in the seal. I tried numerous searchs, Pelican, DIY, etc. Appreciate any tips.
Thx…AJ
It can be a real pain but if I recall, you slide the dust cover down to the bottom of the piston with the bottom flang hanging off just enough to start it in the groove cut in the caliper. Once in place you just slide the piston down into the caliper and the dust cover slides right into place After you have done it once the second one will take about 1 minute to do. Good luck!
^^^ like he said, but…
I cheat. I put the piston in the freezer for a couple hours, and the caliper in the oven with the door open at warm (like 120 degrees - warm, not hot to the touch). The minute difference in clearance this causes helps. I also use a bit of caliper grease…
Thanks guys - I have tried Ken’s method, but I have been using a small amount of brake fluid as lube on the piston and the boot easily slides off the piston while lining it up. I think this will work better with the piston dry and once seated in the caliper then apply lube and slide it down. If there are other techniques, please ring in.
Hi Aj,
you have to put boot on the piston turning it inside out and then put the piston in.
I took step by step pics from when I did it last time - if the above explanation doesn’t make sense (and it probably doesn’t) let me know and I’ll email you pics if you want.
Igor
Hi Igor, I think I understand but yes photos would be great - pls send to ajgoldsmith at yahoo dot com. I’ll take all the help I can get. Now I’ll owe you TWO rounds of brews. How’s your car coming?
thx…AJ
I was looking for the one I originally used years ago but I found this with pictures:
http://www.e30tech.com/forum/showthread.php?t=39965
My E36M3 would push out the dust boot if you wore out a set of track pads, so I got real good at doing this. First one will take you 40 minutes to get that stupid seal in, from then on 5-10 minutes. I can’t see trying to do it dry, use brake fluid or the paste type ATE lube. The E36 fronts are like the Girling’s and I found it easier to put the dust seat on the piston as opposed to into the caliper first. Like described here (http://www.bmw-m.net/TechProc/caliper.htm) in step 17.
Thanks everyone, I have come up with a way of doing this which worked for me, maybe for others. I kept the piston dry, slipped the new seal on over the “outside” lip and slid it down past the grove to the the “inside” end. Keeping it dry helps keep the seal on the piston instead of slipping off. With the seal’s caliper lip hanging over the edge I seated the seal in the caliper. Then use a little brake fluid to lubricate the piston and slide it down into the caliper. Finally, I used my brake caliper compressor tool to seat the piston down into the caliper.
The whole brake rebuild project was pretty inexpensive and easy and I am expecting good results in brake feel. The dust seals on my brakes were pretty torn up and there was a fair bit of gunk down in the caliper behind the piston. The most expensive part is the brass guide pin bushings (I have ATE calipers), but also replaced the seals and the bleed screws while at it. I also used Simple Green and a wire brush on a air grinder to clean up the calipers a bit while off of the car. The whole thing can be done in a day.
I found the old instructions I was looking for. I had a printout in my old M3 stack of papers. I checked the address listed and the guy’s website is no longer online. I’ll try to remember to take it to work so I can scan in that picture for everyone’s future reference.