brakes too sensitive

[ald872000]

Hey Fellas,

My '90 Vic has been running pretty good for the last couple of months an now I have this Brake Pedal problem.

The problem is that when i press on the brake pedal it feels like its too sensitive.
the gradual slow an stop is much more abrupt..

I had the master cylinder, the calipers an pads replaced about 2 years ago.
The fluid level appears to be at normal level when engine is off an on

Any thoughts of what might be causing this problem

[pantera77]

Hey Fellas,

My '90 Vic has been running pretty good for the last couple of months an now I have this Brake Pedal problem.

The problem is that when i press on the brake pedal it feels like its too sensitive.
the gradual slow an stop is much more abrupt..

I had the master cylinder, the calipers an pads replaced about 2 years ago.
The fluid level appears to be at normal level when engine is off an on

Any thoughts of what might be causing this problem

Welcome to the wonderful world of box panthers.
I've yet to drive one that wasn't like this.

[gadget73]

make sure the rear brakes are right. A half stuck wheel cylinder will contribute to this, but the stock brakes are extremely grabby compared to a lot of other vehicles.

[ald872000]

Hey Fellas,

For an old car like this I would think the brake pedal would effect the brakes pretty well half way or 3/4 way down an have a ease at 1/4 to 1/2 the way down..

I press the pedal at 1/4 it feels like I pressed it 1/2 way

an When I press it 1/2 it feels like I pressed it at 3/4

The Measurements aren't accurate but a mental image of what I mean

I've heard that the proportion valve (the mechanism inside the master cylinder) might contribute to this problem?

[FordMan77]

I've helped my Dad troubleshoot this exact issue on his 89 forever. When he had the 84 that I inherited, the brakes were way more balanced. Heck, I got in his just to move the thing out of the driveway and back in and damn near put my head through the windshield when I stopped, lol... I was like WTF??!

Turns out that after a really close inspection of the rear shoes that they were digging into the backing plate for the drums and had created a groove. They would get stuck in this groove and then when they finally popped over the lip- bang! abrupt braking at its finest. You may have to remove the shoes to get a good look at the plate. If you see a shiny spot or groove worn in the plate, then that's a good indication your's is the same way.

Grabbed the good pair of plates of my 89 parts car and swapped them out. Also installed all new hardware in the drums (springs, cables, mounting pins, etc..). After all that was done they seem to do much better and are much more balanced. Also a good time to check over all your brake lines as we had to replace one of his due to rust.

Jay

[ald872000]

I guess I got some Prying to do =)

Thanks for the help fellas

[1980c10]

I have a 91 and its just like this, every time one of my friends drives my car they put us through the windshield it seems like. My older ones where also like this 89, 87,87,86. I think it is just common place on panthers.

[1987cp]

Can always dump the factory combination valve and replace it with separate metering, proportioning, and residual valves like I've recently gotten a start on doing ....

[Southern_Pride]

Brake booster maybe. Mine is fucked up and makes it stop like that. I tend to like it though.

[pantera77]

I have a 91 and its just like this, every time one of my friends drives my car they put us through the windshield it seems like. My older ones where also like this 89, 87,87,86. I think it is just common place on panthers.

Same here. In fact I hate driving different cars now because I get so used to the on/off brakes on my panthers.

[FordMan77]

Can always dump the factory combination valve and replace it with separate metering, proportioning, and residual valves like I've recently gotten a start on doing ....

Or just upgrade to an 03+ like I did :smirk:

Jay

[1987cp]

:confused:

[Lazerbeans]

I am confused too, mine has great brakes. Under 50mph I just lay my foot on the brakes and it stops. No travel, then stop. I have drove alot of vehicles that have to travel an inch or so before they start to function. My Vic isn't like this, no travel. I have driven a few others Vics and never had an issue either, so I don't understand. But on mine everything is top notch, clean fluid, rears adjusted completely, and etc. Maybe something is not 100%, worn out or something. Might flush the system, and make sure all of the hardware (front and back) is in good condition.
Actually I just replaced the fronts. Since the rotors were out of spec, I let'em eat, and the rotors were trashed, and had no pads, just metal. And when I would first drive the car, the brakes would be very touchy. Then after driving awhile they would act normal. When I went to do the brakes, one piston was severely stuck. From what I can tell, since the pistons were extended out so far, they would stick because the seals on the pistons were trashed, and there was corrosion. So until they would loosen up they would be touchy. So from what I can deduce from this, is the brakes are touchy because the fronts are not acting right? I would check the seals, and the condition of the pistons. Now that the fronts pads and rotors have been replaced back to normal. Autozone around here wants $20 for a caliper, so in a few weeks I will replace'em and shoot them with brake paint, so they will look good when/if I get my wheels in about a month.
I have learned a long time ago you goto "dot every I and cross every T" to keep from having problems. Been there done that. I would check for corrosion on the front caliper pistons. and work through the whole system, starting with the cheapest stuff and working my way up. I don't know how any times I have replaced a $20 part, and it was something like a brunt wire or loose connection.

[gadget73]

I got rid of the factory brakes. I hate how touchy they are. The stock brakes lock up far too easily for my liking. Later model big brakes with rear discs are infinitely more controllable. When everything is 100% right, the stock brakes aren't nearly as bad, but they do have very low pedal effort and travel. Its just how they were built. It goes along with the pinky steering and the luggage cruncher on the Towncars. Everything on these things was designed to work with extremely minimal effort. Figure they were built for little old ladies. You don't want grandmom to have to stand on the brakes to stop.

[Mad MAx]

heh my ole lady locked the brakes in the gm up going around a corner oneday and did a 180 perfectly in the road, just kept on goin'.

the brakes on my van are almost as touchy. The idea of upgrading the discs all the way around is relevant to my intrests though.