Odd front brake problem with the new/used Civic

Richard Casto · **Posted:** Fri Aug 01, 2008 2:40 pm

We recently bought a used Civic (same one that had the power door lock issue that I have since solved).

As part of doing some regular maintenance, I noticed that under heavy braking it will lock up the right front wheel first and not lock the left. In my other Civic (same exact model year, etc.) which I have had for years, doesn't do this and both fronts lock up pretty much at the same time. While changing fluid and pads, I noticed that the piston on the left front caliper was very stiff and didn't want to compress as easily. So I was guessing that the left may been applying less pressure which resulted in the right working better and causing the lockup.

So last weekend, I rebuilt both calipers. Both pistons looked good (no pitting or rust) and after being cleaned, new seals and lubricated with the provided grease, both pistons slid right into the calipers just fine. At this time I also put on new rotors and bled the fronts.

And it is still locking up the right front like before. Any ideas?

BriceJohnson · **Joined:** Thu Apr 13, 2006 7:33 am **Posts:** 2230

one brake line is older and has more give to it than the other?

Arthur McDonald · **Joined:** Fri Aug 29, 2003 1:54 am **Posts:** 2052

Your Civic is actually a 5-liter Fox-body Mustang in disguise. It's perfectly normal

Seriously, perhaps a problem with the brake line to the left front - does the flex line balloon up under pressure? Perhaps a pinch in the hard line?
Wild guess - the LF-RR diagonal weight is much greater than the RF-LR (very likely if it is indeed a Mustang). Maybe a bad spring on the RF-LR, or a newer-than-the-rest gas shock on the LF-RR?

BretLuter · **Posted:** Fri Aug 01, 2008 5:40 pm

could be the rubber brake line has collapsed inside- if they're not too expensive, I'd just replace both of them

Richard Casto · **Posted:** Fri Aug 01, 2008 7:51 pm

I will check the hard and flex lines.

I like Art's corner weight idea as well. But under hard braking I would think it would transfer enough weight to the front that it shouldn't matter unless it is seriously out of wack??

MikeWhitney · **Joined:** Wed Aug 20, 2003 9:15 pm **Posts:** 4724

Richard Casto wrote:

I will check the hard and flex lines.

I like Art's corner weight idea as well. But under hard braking I would think it would transfer enough weight to the front that it shouldn't matter unless it is seriously out of wack??

Two crazy ideas off the top of my head:

1. Go do a bunch of hard straight stops then jump out and check the rotor temp with an IR pyrometer. This should (could?) tell you if the RF is getting more brake force all the time or if something else is weird (like weights).

2. Put the front end on jackstands and wedge something in between the seat and the brake pedal to put a small force on the pedal. Put a torque wrench on one lug on each wheel (handle at a tangent to the bolt circle to get a real reading) and find a torque value. This would tell you if there is a bias/sticking issue at small brake pedal displacements.

DickRasmussen · **Posted:** Sat Aug 02, 2008 8:47 am

Mike's ideas are NOT crazy (are they ever?). I have found problems with differential pad heating by doing what he says and/or what I suggest below. The cause can be a stuck caliper piston, etc. (just because the pistons moved fine after the rebuild doesn't mean there isn't some problem such as the piston cocking in the bore) or loose wheel bearings on one side. This would require relatively temp sensitive pads.

Also, did you notice the problem before changing pads? If not, check to be SURE that a pad on one side isn't a little big where it slides in the caliper. (Been there, seen that). This can be fixed with a file.

Do the torque measurements with the brakes COLD first.

Before doing the hard stops do a test drive starting with COLD brakes and do as little braking as possible (use the hand brake) before checking relative L/R temps by feeling the hubs/wheels if you don't have a pyrometer, etc.

If the pads on one side are dragging you should be able to feel the difference with your hand . . . be careful since wheels/hubs get HOT fast with a dragging pad and after heavy braking.

Dick

Richard Casto · **Posted:** Sat Aug 02, 2008 3:28 pm

Speaking of piston cocking in the bore...

On the left side when I rebuilt the caliper, I think I could see some evidence that maybe this was happening. This presented itself as a bit of worn/polished area of the bore. However the piston didn't seem to have any evidence of wear.

I didn't hone the bores. I just used a scotch bright pad to clean them up.

Chuck Branscomb · **Posted:** Sat Aug 02, 2008 3:57 pm

It looks like Cardone reman calipers are ~$47 each at Advance Auto...just a thought.

Richard Casto · **Posted:** Sat Aug 02, 2008 8:56 pm

Chuck Branscomb wrote:

It looks like Cardone reman calipers are ~$47 each at Advance Auto...just a thought.

I hate to admit defeat, but I may do that. I had considered swapping out a caliper from my other civic, but at that price I might as well just buy a reman and see if it works. I just hate the "swap parts until it works" approach.

I did some quick looks and I don't see any problems with the hard or flex lines. It does look like there is some type of distribution manifold right after the master cylinder (one line in and four out). I guess something could be wrong with this, but it is unlikely.

Richard

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Odd front brake problem with the new/used Civic

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