e36 Front Caliper: Assembly Issue

[Earl]

I am having an issue with one of my front calipers that I am rebuilding.

 

I cannot get the piston to slide into the bore. I can get it to slide in when I dry fit the parts, install just the seal (no dust boot), or install just the dust boot (no seal). If I install the seal and the dust boot, the piston will not slide into the bore. It seems to be getting hung up on something.

 

I took the piston off again this morning to see nothing that would cause it to hang up (I have done this more times than I would like to think). There is light corrosion in the rear half of the bore but it doesn't cause any hang-ups during dry fitting.

 

I am thinking that I should still remove that using 600 grit emery cloth.

 

My other front caliper went together very easily and so did both of my rears. I am confused as to what is causing the hold-up. Any ideas? 

 

 

 

[jc43089]

What are you using to lubricate the seals?

[Earl]

Caliper assembly lube. It worked excellent on the other three calipers=) I even used a shit ton to see if it would help and that didn't work at all either. 

 

Edit: I just tried fitting the piston with just the inner seal again. Now that isn't working. It seems like the o-ring won't allow it to pass through. I took it out and set it around the piston to see if it was super tight or what the issue was. The o-ring actually seems to be a good bit larger than the piston (approximately 1/32 gap between the two). Could this be a defective o-ring or could it be swelling from the caliper assembly lube? I am not sure why it may have worked with just the seal before but now it doesn't. I can order another rebuild kit but want to make sure that this o-ring isn't supposed to be like this=)

[merl]

I had one that was difficult to assemble as well ... It just took time and influence and it did finally go together. 

[jc43089]

I would recommend brute force at this point.

[Earl]

I tried multiple brute force methods and it seemed to lodge the piston without driving it in. haha Anyone want to give a hand at assembling this one? I have been trying not to ruin the powder coat as well. 

[Earl]

So I took scotchbrite and cleaned up the inner bore. I then lubricated everything again and tried to reassemble the caliper. It is still a no go. Now to try the piston in the freezer

[Earl]

Still SOL=/

[Earl]

Would anyone be interested in looking at this at the e30 picnic this weekend? It would be nice to be done with the calipers

[Earl]

?

[jc43089]

Just bring it with, I'm sure somebody can look at it.

[Earl]

Lol Was planning on it=P

[industrialsized]

if no one takes car of you txt me and ill get it worked out for you

[Earl]

Thanks Dustin =P I am just confused as to why only one of the four is being a pain lol