How to adjust brakes so that I don't have to push so hard to get good stopping?

[DPP]

Hello,

Looking for some instruction on how to adjust brakes so I don't have to apply so much pressure to get good stopping. I have a 1994 Mustang convertible 3.8L that you have to really firmly push the brake pedal to the floor to make it stop well. It is not spongy or anything abnormal, it just requires a very firm push to the floor to get it to start stopping well. Do you have any recommendations?

Thanks,

Dustin

 

[07GtS197]

So it has a lot of pedal travel? It sounds like a failing master cylinder. Your brakes will still work but you’d have to push them to the floor.

 

[DPP]

I may have mistated something. No, it doesn't have a lot of travel, but you just need to apply very firmly to get it stop--it doesn't go to the floor you just have to apply alot of pressure. Sorry for confusion, but does that make sense?

 

[07GtS197]

Have you checked your brake pads?

 

[ttocs]

maybe needs to be bled/new fluid.

 

[96blak54]

I vote to revamp the 30yr old brake system!

New lines, new pads, new rotors....drilled and slotted and new fluids.

For real tho, your situation may just need a good brake bleeding, fluid change

 

[Fawls]

What sort of booster does it have, Hydro boost or vacuum? and is it working properly.

 

[ttocs]

also reach down to the bottom of the booster and see if you feel any rust as that is where they start and you will not see it till you have it out of the car.

 

[ThoroughbredFckinStallion]

Mine also feels like it's not boosting crap anymore. All the other typical brake issues seem to not be present. I have a stiff pedal and terrible brake performance.

 

[shovel]

Hello,

Looking for some instruction on how to adjust brakes so I don't have to apply so much pressure to get good stopping. I have a 1994 Mustang convertible 3.8L that you have to really firmly push the brake pedal to the floor to make it stop well. It is not spongy or anything abnormal, it just requires a very firm push to the floor to get it to start stopping well. Do you have any recommendations?

Thanks,

Dustin

There's no such thing as adjusting them, part of this is 90s era brakes were simply not as good as modern brakes (as in, if you came from something newer your antique car is going to feel worse...) and part of this is even if they were great brand new they are now ancient and most people have not replaced 30+ year old rubber hoses, etc.

Your lowest hanging fruit here is new soft lines (all of them) and to put the 2 piston PBR front calipers from a new edge on your 94. PBR calipers are way better than your single piston 94 calipers and cost exactly the same amount because they are just stock normal calipers for 99-04 mustangs. For the rear you would only need new pads and soft lines, no need to change rear calipers.

Use pads which are known to be high quality (as in, not what Autozone says) - my opinion is that everything from Powerstop is going to be good quality for a fun daily driver. Remember that you will be buying pads for a 99-04 if you put 99-04 calipers on it. You don't need to buy Powerstop's calipers and you don't need rotors if yours are fine.

That can all be pretty cheap and will likely get you what you want.

 

[ttocs]

seriously reach down under the booster and see if it feels rusty or worse yet wet. If so plan on changing it and doing some cussing when you do, I am not sure if I hated taking it out or trying to wedge it back in worse as they were both a PIA.

 

[Mustang5L5]

Given the age of the system, there could be many issues with it.

If i had to point the finger at something, would be the booster. 94-95 had vac brakes across the lineup. Either the diaphragm has failed, or the check valve has failed. Often times what happens is the MC starts to leak in the bore out the back of the housing and into the booster and kills the diaphragm causing a hard pedal.

If you inspect under the hood, often you'll see peeling paint on the booster under the MC which is signs of a leaking MC. Both item should be changed if this is the case.

You can remove the check valve and just test it by blowing through it.

With the engine off, pump your brakes a few times to purge all vacuum from the booster. Rest your foot on the brake and push slightly. Start the engine. The pedal should sink a little. Shut off the engine. wait 30 seconds or so and then pump the pedal. Should pump 1-2 times with a little hiss and then get hard.

If the pedal doesn't sink when you start, or gets hard immediately when you turn off the booster, replace it.

Could also be other issues as well. Any seized up caliper will cause a harder than normal pedal because the piston doesn't move. Inspect all 4 brakes after a drive and see if they are warm and the same temp. An IR gun helps here. Look at the wear patterns and check the inside surface of the rotor as well and look for anything that doesn't look smooth and clean.

 

[DPP]

Thanks for the recommendations, I will look into it when I get some time.

 

[DPP]

So I did the start up test and everything you said it should do--sinking in after pumping, etc, it did.

 

[DPP]

Here is a pic of the booster--you can see where the MC mates to it there is a trail from fluid and it appears rusty toward the bottom. What does it mean?

 

[DPP]

 

[ttocs]

is it wet on the bottom/rusty?

 

[Frank.JD.Perez]

Technically, you CAN adjust the brakes, but not in a way that the op is asking. A brake proportioning valve would help adjust the pressure from front and rear, but im about 11/10 sure that the ops brakes are all original type components.

So do a full overhaul on the brakes. Rotors, pads, fluids, hoses, etc. Also if this is a 94, theres the difference in size for the master cylinder bore size, so a simple pbr brake upgrade may make the swap feel worse. The op would need to upgrade the MC along with the calipers

 

[Frank.JD.Perez]

Another option... the op could work out and put some muscle on those twig legs

 

[shovel]

There's also this solution but it's likely not what OP is after.