420A Front brake lockup

[zacktaylor2001]

Hey there guys, I'm from Columbus Ohio, I've been having issues with my front brakes locking up, and I've already replaced the brake booster, master cylinder brake calipers pads rotors hardware down to the brake hoses and proportioning valve! Only things left are the brake lines and master reservoir! I had someone tell me he thinks that the reservoir cap might not be airtight any more since it's so old! It's a 1998 Mitsubishi Eclipse GS auto! Does anyone have any ideas?

 

[pauleyman]

define locking up. Like not releasing fully? Fully locked?
Does this car have abs?

 

[zacktaylor2001]

define locking up. Like not releasing fully? Fully locked?
Does this car have abs?

After driving for about 10 minutes whether I use the brakes or not the front brakes start to lock and continue to lock until I can't move the car! The car was built without abs!

 

[zacktaylor2001]

After driving for about 10 minutes whether I use the brakes or not the front brakes start to lock and continue to lock until I can't move the car! The car was built without abs!

After driving for about 10 minutes whether I use the brakes or not the front brakes start to lock and continue to lock until I can't move the car! The car was built without abs!

It's a great running car I just need to figure out this brake locking issue.

 

[pauleyman]

Did you check the wheel bearings? Is this a new development or it's always done this? Did you unhook the brake hoses and pump fluid? If so what happened? Pedal should be easy and return easy. I realize calipers are new but do they slide easily back and forth?

 

[zacktaylor2001]

The pedal keeps getting hard to push when they lock up, this is a new development, no I haven't checked the wheel bearings and I have not disconnected brake hoses and pump fluid

 

[pauleyman]

You did replace rubber hose lines? I have seen brakes with hoses deteriorated and they sort of acted like a check valve.

 

[zacktaylor2001]

Oh yeah I replaced the brakes hoses! And I know if I clamp them I can drive the car with no front brakes

 

[zacktaylor2001]

Oh yeah I replaced the brakes hoses! And I know if I clamp them I can drive the car with no front brakes

The hoses are brand new now! Along with 90% of my brake system!

 

[pauleyman]

Adjust the pedal. check hardlines for damage. Problem seems to be hydraulic given your last post.

 

[pauleyman]

When they're locked have you tried opening the bleed screw? If it shoots out you have pressure in the system and you shouldn't. Trace it back to the master cylinder.

 

[zacktaylor2001]

Ok thanks, so have my brake lines checked and probably replaced!

 

[zacktaylor2001]

When I crack the bleeders the only time it sprays out is with pressure from the pedal!

 

[zacktaylor2001]

I've also replaced the booster and master cylinder!

 

[pauleyman]

when they're locked have you removed the wheel and moved stuff around? If it isn't hydraulic it has to be at the caliper/mount/wheel

 

[zacktaylor2001]

I know the first time they locked my rotors were red hot when I got home! I did take everything apart and replaced just about everything that's easy to do at home with tools and a jack! But it doesn't seem like my wheel hub, bearing or anything like that is broken or bad!

 

[luv2rallye]

Did you have brake work done before this all started? Perhaps you should pump/flush ALL the brake fluid out everywhere and replace with quality brand new fluid. Long shot but perhaps the fluid has water, air, or some type of contaminants in it which is heating up as you drive and thereby expanding to activate the front brakes?

 

[pauleyman]

I agree. Flush the fluid. Once they lock you should be able to determine if it's hydraulic or not. If it isn't there are only so many possibilities. Stick sliders. Stuck piston. Bad wheel bearings. Eliminate each one.