FFR rear brake kit and shims needed

[ehansen007]

Hello FFR'ers,

Posting this up as variances in this may affect us all differently. With the FFR 11.65" rear brake kit there are the brackets and the shims. Upon install I noticed that there would be caliper interference and rubbing right away, however the shims provided aren't enough to offset the caliper. Anyone else seeing this? With no shims I'm right on the metal to metal and probably need at least 1/8" clearance. I spoke to Jim at FFR and he said it shouldn't be a problem. Also it's looking like Moser put some axles that are just a bit short!

https://hosting.photobucket.com/677797bc-aff0-46e3-b9f1-28ba6220f625/9a9833d5-69d5-4188-9ec2-19d69d07a2a5.png

Also, when installing the rear brake pads, you'll want to superglue the shim/sliders into the brake caliper before trying to insert them into the slots. They just fall out otherwise.

https://hosting.photobucket.com/677797bc-aff0-46e3-b9f1-28ba6220f625/b1ecca68-18de-413b-b1b8-87824ecb26ff.png

[ehansen007]

Sorry photobucket is having issues sharing images now. Hope to add some soon. Or ditch them all together.

[Grubester]

Well, I've been dealing with several things -- partially as a matter of course in achieving what I suspect the design intent was:
I'm using the 11.65" rears with IRS on my Mk 4 289 build.

1) I noticed the powder-coated flat bracket that mounts the caliper to the cast aluminum housing (which is basically the spindle) isn't sufficiently parallel to the plane of the disc. So when mounting the caliper, that means the puck that will push on the pads, won't be pushing evenly. I've added other shims to very slightly adjust what should be a parallel relationship.

2) The disc itself has lateral runout of about 0.003" to 0.004", rather than 0.002" max (or what's called 'total indicator reading'). I'm using a 1" travel indicator on a mag base to assess this. I've tried different positions of the disc as mounted on the hub, but same reading (probably means the hub surface is just fine, and doesn't have lateral runout problem itself).

3) When trying to insert the pads into the calipers with those pesky clips installed -- it wasn't going to happen. I measured the I.D. of the milled portion of the caliper that should receive the pads AND measured the material thickness of the clips (X2) and the dimensions show "it's impossible". I carefully ground material off the two ears on each pad (probably a good 0.008" or 0.010") and they could then fit per the intended design.

4) TRICK: to hold the pair of clips in place once you've cleaned up the dimensional needs, use a 1/2" piece of blue painters tape to hold them in place while you get the first pad in. I thought I'd need 'extra hands' but the tape trick works fine and can be stripped off easily once both pads are in place.

-Steve, Junction City, OR (yeah, trains blow through here, but they're far enough away, so it's more quaint than an irritant.)

[Grubester]

BTW, I've discovered that shims are a reality in these builds. I found I had to smarten-up the control arm assemblies for the right amount of 'crush' (a goldilocks situation) on the polyurethane bushings. I bought special die-button washers/shims (5/8" ID x 7/8" OD) in two thicknesses: 0.005" & 0.015" to use with the inner steel sleeves that come with the polyurethane assemblies. Further, the ends of the provided steel sleeves are cut with probably a cutoff saw and have rough faces, preventing a sufficiently tight contact to either the control arm's frame-welded mounting flanges -- or against the suggested washers provided by FFR to accommodate the suspension options. I suspect the grease that leaks out on the bolt head side or the nut side of the large mounting bolts are because of bad contact with the sleeve face. Grease should only ooze along the length of the sleeve and up the face of the polyurethane.
I also had to grind special thickness washers to take up the ~0.100" space for the two front mounting bolts for the pumpkin. I do not want extra clearance in the mounting of something that has ~400hp winding through it!

-Steve Grube

[ehansen007]

I tried the painters tape but it wouldn't stick and hold. That's why I glued them. They are so tight. I should have taken down the ears just a bit. Now I'm going to just think about them hanging up in there.

[ehansen007]

I tried the painters tape but it wouldn't stick and hold. That's why I glued them. They are so tight. I should have taken down the ears just a bit. Now I'm going to just think about them hanging up in there. As it turned out with the shims/washers for the brake bracket I used two 5/16" washers per bold on the left and only needed one on the right. Nice work Moser! LOL

[Grubester]

When using the painters tape, I wound it around and attached it to itself (I'd send a picture, but the Forum's pic scheme is weird). You're saying "they are so tight". Are you referring to the sheet metal shims, because if so, they should be shaped (trimmed) further so they fit fully conformally into their recesses. THEN the pads can be inserted. The ears may need slight grinding to fit into the caliper. It's a trick to manage all the holding and insertion.

[Grubester]

Okay, I'm going to try to attach a photo of the tape holding the shims in place on the caliper (duct tape, no painter's tape) (not sure if pic will be attached....)
205494

[rkl20678]

Thanks for this. I thought I had gone lame in my thinking and ability. I will make the grinding adjustments necessary. Not a good system design.

[rponfick]

I am starting on my Mk5 standard FFR rear brake install and was frustrated by no instructions whatsoever in the manual, but after some searching found reference in old post to FFR website instructions.
Also, I see in this thread comments about keeping the pad clips/shims in place. My supplied components for the rear brakes do not include any of the clips (which the front brakes did), so I wonder if something has changed recently, and instructions on FFR website instructions don't show or mention them. ??????
Any ideas?
Ralph

[tnt_motorsports]

My rear brake kit did not include any shims or clips either. I bought a kit of Amazon for mine. I'm guessing you only need the 8 pieces that go on the pad ears, but I couldn't find just those.

https://www.amazon.com/dp/B001PYR24C?ref=ppx_yo2ov_dt_b_fed_asin_title

[rponfick]

That brings up a good question, are they really needed, or do we have a problem if we follow FFR directions? Something is not right.

[rkl20678]

In the end I had to epoxy the clips in place and then grind down the pad ears to fit. A miserably designed caliper. I just hope they are reasonable brakes for stopping the car. It was also kitted improperly with SAE bolts for metric threads with a bolt that interferes with the e-brake cable. I have been very happy with FFR fit, finish and quality but on occasion they cut corners. It is on the builders to see those cut corners and make the improvements needed to get the outcome one wants.

[rkl20678]

I want to add that there are so many variables when builders select their rear end selection that FFR cannot cover them all. Just go with what you get and adjust based on your selected set up.

[rich grsc]

Install the clips in the round file. ....But if you think you absolutely need them, then just grind a small amount off the ends of the pads. It's really just that simple, how do so many not see the easy solution? :confused:

[PMD24]

Like several have said, grind the ears on the pads to fit the slots in the caliper before you do anything else.

The painted bracket does in fact not sit flat on the spindle because it hits a high spot. That positions it so it is not parallel with the rotor. Also the hub openings in the rotors are likely out of round and catch on the hub resulting in the rotor not sitting flat on the machined surface of the hub. You will likely need to file them a bit to get them to seat properly on the hub. All these things need to be corrected. And then... you will find that the caliper doesn't sit parallel to the rotor. That's where the shims come in.

I detailed all of this in my build thread starting at post 65. E-brake info at post 86. Hopefully it will be of some help.

Pat

[rponfick]

My rear brake kit did not include any shims or clips either. I bought a kit of Amazon for mine. I'm guessing you only need the 8 pieces that go on the pad ears, but I couldn't find just those.

https://www.amazon.com/dp/B001PYR24C?ref=ppx_yo2ov_dt_b_fed_asin_title

I ordered this referenced Dorman HW5618 and it does not seem to be the same larger clips shown in photos here. Not sure how these 8 small clips would fit. I may just take rich grsc suggestion and forget the whole subject.

[tnt_motorsports]

They go on the ears of the pads. Keep in mind these are to aid in the pad moving back and forth in the caliper slides and to reduce the wear of the more expensive parts. I installed mine with no grinding or modification at all.