I just completed replacing the front and rear brake pads and rotors on my 1985 GSL. The rear pads were heavily worn (worn out), but the fronts showed very little wear. This seems pretty unusual. Thoughts?

 

Welcome to the board.

On it's face, it does sound unusual. However, first it might be better to share how long you've had the car and if you know whether or not the pads (all 4) were changed at the same time whenever the brakes were last done.

 

Its a one owner vehicle, purchased in 1985. Stored every winter. Mileage is 26K. This is the first time the brakes have been touched. The rears were done first, after they started making the usual wear noises. There were never any significant issues noted (pulling, etc.), but in hindsight the braking has felt soft for the last couple of driving seasons. When I drove the car after both sets of brakes were redone, I noted that I could not get the brakes to lock up when going forward, but could get the brakes to lock up driving backwards

Thanks for you comments.

 

Not intimately familiar with that generation, but thinking out loud...

*Check to make sure the e-brake is releasing completely and not sticking.

*Wheel cylinders rusted/sticking, calipers needing rebuild. The car is 35 yrs old. If it sits a lot and the brakes “have never been touched” a rebuild is probably needed...with a complete brake fluid flush.

*Check, or simply replace the soft brake lines. I had one on an antique car of mine go bad. I speculate that the inner wall of the line separated and acted like a one-way valve...not letting the wheel cylinder completely return.
Old brake lines might also explain some of the “soft” feeling you described.

* Check or replace the proportioning valve.

 

I suppose I'm going to reiterate what Sgtblue posted, but I think he's right. You probably need to start with rebuilding the calipers and replacing all the lines. The e-brake could be the culprit. My MR2 Turbo cables would act funny and not release sometimes - bad enough to cause smoking - but that's neither here nor there right now. If this is the first time the brakes have been touched, then I would tend to think hydraulic - like maybe the pistons are not moving freely. A good flush may do the trick, but after all this time, a rebuild may be the safer, more prudent choice. You should definitely look into the proportioning valve as well.

 

Often times rust forms on the caliper bracket's bridges and this forces pressure on the pads and causes them to stock in the caliper bracket. Once the pads are sticking, they will wear much faster due to not being able to slide away from the rotor when the brakes are not being applied. This is why it's very important to clean the bridges and the fitting kit when replacing the pads and rotors.