WEIRD brake problem

[thisolechevy]

My 91 Talon TSI has been very reliable until now...when the car and motor are cool the brakes are perfect!! but then as you drive it and the motor warms up you have to pump the brakes to get them to work. Then after you park the car the rotors, calipers, and even wheels are extremly hot, so I figured calipers had locked up. But I jacked up the car and could spin the wheels freely with no catching at all. But both inner and outer brake lines on both sides are cracked quite a bit, could htis be the reason?

 

[PeteGSX95]

Did you check for leaks in the lines?? And aslo check the fluid level if its too low it could cause the problem.

 

[thisolechevy]

nope I couldnt find any leaks at all and the brake fluid level hasnt changed at all. Still right at the maximum line, and like I said the work PERFECT when they are cold.

 

[PeteGSX95]

IF they were extremly hot thay would have to be rubbing even a littel bit of contact could cause the heat. After you drive the car for a bit take the wheel off and have someone step on the pedal and let offof it and look to see if the calipers are releasing all the way.

 

[Mitsu RacerX]

no to be stupid have you checked to see if your piston caliper is or have been pushed out to far, which would make them stick and get hot. On my 95 RS turbo my brakes had to be pumped (once) before it would catch. When I took it off it looked fine. I then found out that the piston had been pushed out to far and had messed up the caliper. It might help you if not sorry man...

 

[No_Skillz]

Have you considered the possibility of air or water in your lines? If there is either, it will expand as temperature increases, causing your brakes to engage(hence the high brake temps), in addition to lessened brake feel (hence the pumping). Try a bleed.

 

[toybreaker]

If all four rotors are hot;

There is a thermal compensating port in the master cylinder. It's generally where the fluid enters from the reservoir.

With the pedal up, fluid can enter or leave the master cyinder as the fluid expands and contracts due to variances in temperature in the brake hydraulics or engine compartment.

The master cylinder piston closes the fluid inlet off on it's way by as the brake pedal is depressed, thus creating a sealed cylinder.

If the port is blocked by debris, or an incorrectly adjusted pushrod, no fluid can escape the system as it expands due to an increase in temperature and pressure is created. This puts pressure to the whole system, and will drag all four corners a schosche, creating heat.

If only one wheel is an issue, a sticking caliper piston or slider pin may be to blame.

On very rare occaisons, I've seen some hose issues. They can take various forms. Usually it's just a restriction, and you can feel it as a pull when the brakes are applied. There are some variations, but mostly, the restriction just changes the time scale of actuation/release at that wheel, eventually, the pressures equal out.

If you let your caliper dangle from the brake hoses as you work on the brakes, bad things can happen to the hoses. ALWAYS support the caliper. I use a bungy thru the caliper and up to the spring/strut to support the caliper out of the way. If'n you just lay the caliper up accross the axle or whatever, you're bound to knock it off, and it will fall till the hose stops it, which traumatises the hose, usually at the ends.....not good.

Anytime I even suspect a hose may have issues, I will replace it. There's a whole bunch of cost effective stainless hoses for these cars. Any question of hose integrity is an invation to upgrade

I repeat, Don't take a chance on a brake hose. The only time you really need your brakes, you hit them hard, and that's when a hose will burst....

And it's hard to pick little bits of a wheelchair/shopping cart/ small dog out of your fmic....

 

[thisolechevy]

WOW thanks for the response guys!! I have ordered the new brake lines just to be safe but I will take off the calipers and see if they have an issue. I do complete brake jobs at my work I had just never run into this type of situation with them. And because its my car I cannot work on it at the shop (real bummer)
But thanks