I have what I think might be a brake issue, and was hoping for some help diagnosing.

When traveling at higher speeds, say 50+, and lightly getting on the brakes, I get an initial tug towards the left for at most a second. Then the car brakes straight. I know normally a constant tug or dive one way under braking is generally a caliper issue. However, it seems odd to me that it is only an initial second that this happens. Also under hard braking, it stops straight, and in the past when I have had a bad caliper, hard braking tended to make the car pull to the side much more.

Not sure if this is related or not, but I have another symptom of some dead pedal travel. I don't think this is really new, but the brake pedal definitely has a bit of travel before I get any bite. Once I start getting bite, I get normal brake activity, linear increase in braking with pedal effort. No spongy or soft feeling, etc.

Front brakes are fairly new, with a couple thousand miles on them. The rears have a decent number of miles, but probably have 50% or more of pad life remaining.

Any ideas what this initial, momentary pull might be caused by? Maybe a sticking caliper? Or a brake line problem? (Clog, leak, etc)? Something else?

[This message has been edited by Fformula88 (edited 04-11-2009).]

Bleed the the front brakes ,,check for equal squirt pressure from each bleed valve .. make sure the driver side has the same pressure as the passenger ,,put some clean white paper under the master cylinder,, this is to check for leak from the forward port.it is normally a very slow,,small leak..
You are looking for a leak at the caliper ..OR the proportioning valve is not passing fluid properly..
you want to make sure the proportioning(combination valve ) is sending pressurized fluid to the caliper normally if the proportioning valve,, it will be the driver side this is the forward line .it comes out the front..
Up to 70% of the fiero brake power is from the front wheels
you can fill the driver side line with fluid this seems to help the valve ,,when a fiero sits for a long period,, 2 years or longer, this metering valve gets lazy.. it sits right beside the master cylinder on the fender side ,,2 lines run fron the master to the proportioning valve called the combination valve in the manuals
check the calipers and rotors for fluids of course..A leaking caliper will deposit brake fluid on the inner pad and back side of the rotor

I'd say it a collapsing front flex hose, probably the right since it pulls to the left initially. My theory is that when you hit the brakes the left comes on more than the right initially, hence the pull. Eventually the fluid makes it through the hose and evens things up.

I had a sticking rear caliper on my 85 and it was the hose. hard to believe how much difference an unblocked hose cane make.

Try bleeding the fronts. If the right puts up a fight when pressing on the pedal then replace the hose.

Cannot comment on the dead brake travel.

------------------
Dave

www.ltlfrari.com

Thanks for the info. I'll run some of the tests tomorrow.

I know the lines, calipers, pads appear free of fluid, including back of rotors. They all look dry to me. Would a leak before the rubberized lines cause an issue similar to a leak at the caliper? I do have some kind of fluid leak at the left rear of the car that I do not think is directly out of the engine (my engine leaks oil from a few spots too) and therefore could be a non oil leak. I have been thinking it is tranny fluid, but maybe it is brake out of a hard line? I thought I had traced it to the tranny coolant line, but maybe it is brake?

Well, as I said, I'll run your suggested tests tomorrow since it is getting late, see if I cannot find out more.

Thanks a bunch!!

Also, if the caliper sliders (in this case the right front) are beginning to stick it could cause a momentary pull to the left under light braking. When the brakes are applied the piston pushes the inside pad toward the rotor which then slides the caliper so the outside pad contacts the rotor and pinches it between the two pads. If the sliders are binding, you wont have full contact on one side until the brakes are applied hard enough to force the caliper to slide, however, this usually leads to calipers hanging up in the applied position.

This should be pretty easy to check. Take the wheel off and grab the caliper (make sure its not hot first!) and try to rock it back and forth on the sliders. Compare each side, if one is harder to slide than the other, take the caliper off and lube the slider pins and where the calipers contact the brackets.

If they are sliding fine, then start checking the physical looks of the lines. If any of them seem like they are in particularly bad condition, start there.

-Joe